MultimediaWiki - User contributions [en]

FFmpeg Summer of Code 2014

2014-02-08T18:27:35Z

Reynaldo: /* Basic servers for network protocols */

This page is on wiki.multimedia.cx due to trac.ffmpeg.org being down for maintainance. It might be moved back later.

= Introduction =

FFmpeg is the universal multimedia toolkit: a complete, cross-platform solution to record, convert, filter and stream audio and video. It includes libavcodec - the leading audio/video codec library.

[https://developers.google.com/open-source/soc/ Google Summer of Code (GSoC)] is a program that offers students stipends to write code for open source projects. Through the guidance of mentors, students gain valuable experience interacting with and coding for open source projects like FFmpeg. Additionally, the project and its users benefit from code created from students who often continue contributing as developers. FFmpeg participated to several past editions ([[FFmpeg Summer Of Code 2006|2006]], [[FFmpeg Summer Of Code 2007|2007]], [[FFmpeg Summer Of Code 2008|2008]], [[FFmpeg Summer Of Code 2009|2009]] and [[FFmpeg Summer Of Code 2010|2010]]), and we are looking forward to being involved this year.

This is our ideas page for [http://www.google-melange.com/gsoc/homepage/google/gsoc2014 Google Summer of Code 2014]. See the [http://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2014/help_page#2._What_is_the_program_timeline GSoC Timeline] for important dates.

== Information for Students ==

=== Getting Started ===

# '''Get to know FFmpeg.''' If you are a student and interested in contributing to an FFmpeg GSoC project it is recommended to start by subscribing to the [http://ffmpeg.org/mailman/listinfo/ffmpeg-devel ffmpeg-devel] mailing-list, visiting our IRC channels (''#ffmpeg-devel'' and ''#ffmpeg''), and exploring the codebase and the development workflow. Feel free to [[#Contacting_FFmpeg|contact us]] if you have any questions.
# '''Find a project.''' Listed on this page are mentored and unmentored projects. Mentored projects are well-defined and mentor(s) have already volunteered. Unmentored projects are additional ideas that you may consider, but you will have to contact us to find a mentor. You may also propose your own project that may be a better match for your interest and skill level. If a project description is unclear or you have any questions, do not hesitate to contact its mentor or admin.
# '''Contact us.''' If you find a project that you are interested in then get in touch with the community and let us know. In case you want to work on a qualification task, you should ask the respective mentor(s) so that the task can be claimed.
# '''Apply.''' Student proposal period begins 10 March 19:00 UTC and ends 21 March 19:00 UTC. See the See the [http://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2014/help_page#2._What_is_the_program_timeline GSoC timeline] for additional information.

=== Qualification Tasks ===

In order to get accepted you will be requested to complete a small task in the area you want to contribute. FFmpeg GSoC projects can be challenging, and a qualification task will show us that you are motivated and have the potential to successfully finish a project.

The qualification task is usually shown in the project description. Contact the respective mentor(s) for assistance on getting a related qualification task or if you want to propose your own. You can also browse the [https://trac.ffmpeg.org FFmpeg Bug Tracker] for qualification task ideas.

=== Contacting FFmpeg ===

If you have questions or comments feel free to contact us via our mailing list, IRC channel, or e-mail one of the FFmpeg GSoC admins:

* '''Mailing-list:''' [http://ffmpeg.org/mailman/listinfo/ffmpeg-devel ffmpeg-devel]
* '''IRC:''' ''#ffmpeg-devel'' on Freenode
* '''FFmpeg GSoC Admin:''' [[User:Michael|Michael Niedermayer]] (''michaelni'' in #ffmpeg-devel on Freenode IRC)
* '''FFmpeg GSoC Backup Admin:''' [[User:Stefanosa|Stefano Sabatini]] (''saste'' in #ffmpeg-devel on Freenode IRC)

You can also contact a mentor directly if you have questions specifically related to one of the projects listed on this page.

= Mentored Projects =

This section lists well-defined projects that have one or more available mentors. If you are new to FFmpeg, and have relatively little experience with multimedia, you should favor a mentored project rather than propose your own. Contact the respective mentor(s) to get more information about the project and the requested qualification task.

== Animated Portable Network Graphics (APNG) ==

[[File:Animated PNG example bouncing beach ball.png|right|link=]]

'''Description:''' FFmpeg currently does not support Animated PNGs, the goal of this project is to change that and add support. The little bouncing ball animation shown to the right is such a APNG file.

'''Specification:''' https://wiki.mozilla.org/APNG_Specification

'''Expected results:'''
* APNG demuxer
** implement robust probing:
*** PNG images are not misdetected as APNG animations
*** APNG animations are not misdetected as PNG images
** splits stream into sensible packets (so they can be easily reused in APNG muxer)
** survives fuzzing (zzuf)
** add FATE coverage, coverage should be at least 70%
** test code under valgrind so no invalid reads/writes happen

* APNG decoder
** use existing PNG decoder code (write decoder in same file)
** implement parsing of all APNG chunks (acTL, fcTL, fdAT)
** error handling
** survives fuzzing (zzuf)
** add test for FATE, coverage should be at least 75%
** CRC checksum validation
** test code under valgrind so no invalid reads/writes happen

* APNG muxer && APNG encoder
** use existing PNG encoder code (write encoder in same file)
** write compliant files, make sure they play correctly in major web browsers that support APNG
** add test for FATE

'''Prerequisites:''' C coding skills, basic familiarity with git.

'''Qualification Task:''' Implement format autodetection for imagepipe and image demuxer.

'''Mentor:''' [[User:Pbm|Paul B Mahol]] (''durandal_1707'' in #ffmpeg-devel on Freenode IRC)

'''Backup mentor:''' [[User:Suxen_drol|Peter Ross]] (''pross-au'' in #ffmpeg-devel on Freenode IRC)

 

== FFv1 P frame support ==

'''Description:''' FFv1 is one of the most efficient intra-only lossless video codecs. Your work will be to add support for P frames with motion compensation and motion estimation support (the existing motion estimation code in libavcodec can be reused here). Then fine-tune it until the best compression rate is achieved. This will make FFv1 competitive with existing I+P frame lossless codecs like lossless H.264.

'''Expected results:''' State of the art P frame support in the FFv1 encoder and decoder implementation.

'''Prerequisites:''' C coding skills, basic familiarity with git, solid understanding of video coding especially with motion compensation.

'''Qualification Task:''' Implement support for simple P frames without motion compensation in FFv1. That is so that each frame stores the difference to the previous frame.

'''Mentor:''' [[User:Michael|Michael Niedermayer]] (''michaelni'' in #ffmpeg-devel on Freenode IRC)

'''Backup mentor:''' TBA

 

== Misc Libavfilter extension ==

[[File:Lavfi-gsoc-filter-vintage-illustration.jpg|right|link=]]

'''Description:''' Libavfilter is the FFmpeg filtering library. It currently supports audio and video filtering and generation support. This work may focus on porting, fixing, extending, or writing new audio and video filters from scratch.

Candidate filters for porting may be the remaining MPlayer filters currently supported through the mp wrapper, libaf MPlayer filters, and filters from other frameworks (e.g. mjpegtools, transcode, avisynth, virtualdub, etc.). In case of mp ports, the student should verify that the new filter produces the same output and is not slower.

Some ideas for more filters:
* a frequency filtering domain filter relying on the FFT utils in libavcodec
* a controller filter which allows to send commands to other filters (e.g. to adjust volume, contrast, etc.), e.g. like the sendcmd filter but through an interactive GUI
* a lua scripting filter, which allows to implement filtering custom logic in lua

For more ideas check [https://trac.ffmpeg.org/query?status=new&status=open&status=reopened&component=avfilter&col=id&col=summary&col=status&col=type&col=priority&col=component&col=version&order=priority trac libavfilter tickets].

'''Expected results:''' Write or port audio and video filters and possibly fix/extend libavfilter API and design when required.

'''Prerequisites:''' C coding skills, basic familiarity with git. Some background on DSP and image/sound processing techniques would be a bonus but is not strictly required.

'''Qualification Task:''' write or port one or more filters

'''Mentor:''' TBA

'''Backup mentor:''' [[User:Ubitux|Clément Bœsch]] (''ubitux'' in #ffmpeg-devel on Freenode IRC)

 

== Subtitles ==

'''Description:''' FFmpeg has been working on improving its subtitles support recently, notably by adding the support for various text subtitles and various hardsubbing (burning the subtitles onto the video) facilities. While the theme may sound relatively simple compared to audio/video signal processing, the project carries an historical burden not easy to deal with, and introduces various issues very specific to its sparse form.

'''Expected results:'''
* Add support for new subtitles formats. Example: a demuxer for .SUP files, just like VobSub but for Blu-Ray, or a VobSub muxer.
* Improve text subtitles decoders. Typically, this can be supporting advanced markup features in SAMI or WebVTT.
* Update the API to get rid of the clumsy internal text representation of styles
* Proper integration of subtitles into libavfilter. This is the ultimate goal, as it will notably allow a complete subtitles rendering for applications such as ffplay.
* BONUS: if everything goes well, the student will be allowed to add basic support for teletext

'''Prerequisites:''' C coding skills, basic familiarity with git. Some background in fansubbing area (notably ASS experience) would be a bonus but is not strictly required.

'''Qualification Task:''' write one subtitles demuxer and decoder (for example support for Spruce subtitles format). This is in order to make sure the subtitles chain is understood.

'''Mentor:''' [[User:Ubitux|Clément Bœsch]] (''ubitux'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' TBA, possibly Nicolas George (''Cigaes'' in #ffmpeg-devel on Freenode IRC)

 

== Postproc optimizations ==

[[File:PostProc.jpg|right|link=]]

'''Description:''' FFmpeg contains libpostproc, which is used to postprocess 8x8 DCT-MC based video and images (jpeg, mpeg-1/2/4, H.263 among others). Postprocessing removes blocking (and other) artifacts from low bitrate / low quality images and videos. The code though has been written a long time ago and its SIMD optimizations need to be updated to what modern CPUs support (AVX2 and SSE2+).

'''Expected results:'''
* Convert all gcc inline asm in libpostproc to YASM.
* Restructure the code so that it works with block sizes compatible with modern SIMD.
* Add Integer SSE2 and AVX2 optimizations for each existing MMX/MMX2/3dnow optimization in libpostproc.

'''Prerequisites:''' C coding skills, good x86 assembly coding skills, basic familiarity with git.

'''Qualification Task:''' convert 1 or 2 MMX2 functions to SSE2 and AVX2.

'''Mentor:''' [[User:Michael|Michael Niedermayer]] (''michaelni'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' TBA

 

== Bayer RGB colorspaces ==

[[File:350px-Bayer_pattern_on_sensor.svg.png|right|link=]]

'''Description:''' Several image and video format store pixels using Bayer-pattern colorspaces. Supporting these format would broaden FFmpeg's applicability to RAW still and video photography processing.

'''Expected results:'''
* Rebase existing patches
* Implement high quality bayer transformations in libswscale (plain C)
* Add bayer formats to the libavutil pixfmt enumeration routines
* SIMD optimizations of the libswscale transformations
* Complete PhotoCINE demuxer to support Bayer format; (or another format of your choosing)

Optional goodies:
* Extend TIFF decoder to support DNG-Bayer format
* Support a popular proprietary camera format (many to choose from; see dcraw project)

'''Prerequisites:''' C coding skills, basic familiarity with git.

'''Qualification Task:''' Implement a simple and working Bayer->RGB transform in libswscale

'''Mentor:''' [[User:Suxen_drol|Peter Ross]] (''pross-au'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' [[User:Michael|Michael Niedermayer]] (''michaelni'' in #ffmpeg-devel on Freenode IRC)

 

== MPEG-4 Audio Lossless Coding (ALS) encoder ==

[[File:Showwaves_green.png|240px|right|link=]]

'''Description:'''
A MPEG-4 ALS decoder was implemented several years ago but an encoder is still missing in the official codebase. A rudimentary encoder has already been written and is available on [https://github.com/justinruggles/FFmpeg-alsenc.git github]. For this project, that encoder is first to be updated to fit into the current codebase of FFmpeg and to be tested for conformance using the [http://www.nue.tu-berlin.de/menue/forschung/projekte/beendete_projekte/mpeg-4_audio_lossless_coding_als/parameter/en/#230252 reference codec and specifications]. Second, the encoder is to be brought through the usual reviewing process to hit the codebase at the end of the project.

'''Expected results:'''

* Update the existing encoder to fit into the current codebase.
* Ensure conformance of the encoder by verifying using the reference codec and generate a test case for FATE.
* Ensure the FFmpeg decoder processes all generated files without warnings.
* Enhance the rudimentary feature set of the encoder.

'''Prerequisites:''' C coding skills, basic familiarity with git. A certain interest in audio coding and/or knowledge about the FFmpeg codebase could be beneficial.

'''Qualification Task:''' Add floating point support to MPEG-4 ALS decoder

'''Mentor:''' [[User:Pbm|Paul B Mahol]] (''durandal_1707'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' TBA

 

== Hardware Acceleration API Software/Tracing Implementation ==

'''Description:''' Our support for hardware accelerated decoding basically remains untested. This is in part due to FFmpeg only implementing part of the required steps and in part since it requires specific operating systems and hardware.

The idea would be to start with a simple stub implementation of an API like e.g. VDPAU that provides only the most core functions. These would then serialize out the function calls and the data they get to allow for easy comparison and thus regression testing. Improvements to this approach are adding basic input validation and replay capability to allow testing regression data against real hardware. This would be similar to what apitrace https://github.com/apitrace/apitrace does for OpenGL.

A further step would be to actually add support for decoding in software, so that full testing including visual inspection is possible without the need for special hardware.

'''Prerequisites:''' C coding skills, basic familiarity with git

'''Qualification Task:''' Anything related to the hardware acceleration code, though producing first ideas and code pieces for this task would also be reasonable

'''Mentor:''' Reimar Döffinger (''reimar'' in #ffmpeg-devel on Freenode IRC, but since I'm rarely there better email me first: Reimar.Doeffinger [at] gmx.de)

'''Backup Mentor:''' TBA

 

== AAC Improvements ==

'''Description:''' FFmpeg contains an AAC encoder and decoder, both of them can be improved in various ways. This is enough work for more than one GSoC project, so one part of your submission would be to define on which task exactly you want to work.
* AAC BSAC decoder: This has already been started, but the existing decoder still fails on many samples
* AAC SSR decoder
* AAC 960/120 MDCT window

'''Qualification Task:''' See the FFmpeg bug tracker for AAC issues, fixing one of them or rebasing the existing incomplete BSAC decoder for current git head or fixing one or more existing bugs are possible qualification tasks.

'''Prerequisites:''' C coding skills, basic familiarity with git, knowledge about transform based audio coding would be useful.

'''Mentor:''' Baptiste Coudurier (''bcoudurier'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' TBA

 

== DTS / DCA Decoder Improvements ==

'''Description:''' FFmpeg contains a DTS decoder, but its missing several features
* DTS-HD decoder improvements: A possible qualification task is to implement ticket [https://trac.ffmpeg.org/ticket/1920 #1920]
** Add support for X96 extension (96khz)
** Add support for XLL extension (lossless)
** Add support for pure DTS-HD streams that do not contain a DTS core
** Add support for multiple assets
** Add support for LBR extension

'''Prerequisites:''' C coding skills, basic familiarity with git. Good understanding of DTS and related audio coding is a strict requirement.

'''Mentor:''' Benjamin Larsson (''merbanan/merbzt'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' TBA

 

== DCA Encoder improvements ==

'''Description:''' Add more complete multichannel support, subband adpcm support and optimize the decorrelation transform. A [http://wiki.multimedia.cx/index.php?title=Mirror specification] is available.

'''Prerequisites:''' C coding skills, basic familiarity with git. Good understanding of DTS and related audio coding is a strict requirement.

'''Qualification Task:''' Add 3.0 / 3.1 support and fix the channel order for 5.1

'''Mentor:''' Benjamin Larsson (''merbanan/merbzt'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' [[User:Michael|Michael Niedermayer]] (''michaelni'' in #ffmpeg-devel on Freenode IRC)

 

== MXF Demuxer Improvements ==

'''Description:''' The MXF demuxer needs a proper, compact way to map EssenceContainer ULs to WrappingKind. See [https://trac.ffmpeg.org/ticket/2776 ticket #2776] in our bug tracker, and [https://trac.ffmpeg.org/ticket/2776 ticket #1916] contains additional relevant information.

Essence in MXF is typically stored in one of two ways: as an audio/video interleave or with each stream in one huge chunk (such as 1 GiB audio followed by 10 GiB video). Previous ways of telling these apart have been technically wrong, but has worked due to a lack of samples demonstrating the contrary.

'''Expected results:''' The sample in ticket [https://trac.ffmpeg.org/ticket/2776 ticket #2776] should demux correctly. Add a test case in [http://ffmpeg.org/fate.html FATE]. The solution should grow libavformat by no more than 32 KiB.

'''Prerequisites:''' C coding skills, basic familiarity with git.

'''Qualification Task:''' Investigate if there may be a compact way of representing the UL -> WrappingKind mapping specified in the [http://www.smpte-ra.org/mdd/RP224v10-publication-20081215.xls official RP224 Excel document]. The tables takes up about half a megabyte verbatim which is unacceptable in a library as large as libavformat.

'''Mentor:''' Tomas Härdin (''thardin'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:'''

 

== Symmetric-key block ciphers ==

'''Description:'''
FFmpeg contains the libavutil library, which is a utility library to aid portable multimedia programming. It contains, among other things, standard cryptographic algorithms, like AES or Blowfish. The goal of this project is to add support for three other common block ciphers: CAST-128, Twofish and Camellia.

'''Specification:'''
* http://tools.ietf.org/search/rfc2144
* https://www.schneier.com/twofish.html
* http://tools.ietf.org/html/rfc3713

'''Expected Results:'''
* Implement CAST-128, Twofish and Camellia in C
* Support for ECB and CBC modes
* Ensure code works with all key sizes supported by an algorithm
* Ensure code is conformant to the standard and passes test vectors
* Ensure code does not attempt any invalid read or write using valgrind
* Simple C-level optimization to get comparable speed with other crypto libraries

'''Prerequisites:'''
C coding skills, basic familiarity with git. Basic understanding of cryptography. Understanding of block ciphers. C-level code optimization.

'''Qualification Task:''' Anything related to cryptography, like proving you can implement a cryptographic hash function or a HMAC function in C. The student can also propose his own qualification task.

'''Mentor:''' Giorgio Vazzana (''Holden'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' [[User:Michael|Michael Niedermayer]] (''michaelni'' in #ffmpeg-devel on Freenode IRC)

== VDPAU filter ==

'''Description:''' VDPAU is not only about hardware-accelerated decoding but also allows some postprocessing, most notably deinterlacing. Other features of the API include scaling, noise removal and a sharpening filter.

'''Expected results:''' Implement a filter that allows using the postprocessing features as defined by the VDPAU API. This should particularly include the deinterlacer, ideally all features should be usable to allow comparing the quality and performance of different hardware and hardware vs. software.

'''Prerequisites:''' C coding skills, you will need hardware that allows VDPAU post-processing.

'''Qualification Task:''' Show that you are familiar with the FFmpeg filter system, either by porting one or more of the remaining postprocessing filters from the MPlayer compatibility layer (files ''vf_*pp*.c'' in ''libavfilter/libmpcodecs'', see for comparison commit [http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=a2c547ff a2c547ff]) to a native filter or by implementing a very simple inverse telecine filter under LGPL that allows to reverse the effect of the telecine filter.

'''Mentor:''' [[User:ce|Carl Eugen Hoyos]] (''cehoyos'' in #ffmpeg-devel on Freenode IRC)

'''Backup Mentor:''' Reimar Döffinger (''reimar'' in #ffmpeg-devel on Freenode IRC, Reimar.Doeffinger [at] gmx.de)

== Basic servers for network protocols ==

'''Description:''' libavformat contains client for various network protocols used in multimedia streaming: HTTP, RTMP, MMS, RTSP. Your work will be to implement the server side for one or several of these protocols.

The libavformat framework is not designed to build general-purpose server applications with several clients, and nothing similar to the configuration features of real servers like Apache is expected, but libavformat should be able to stream a single predefined bytestream to/from a single client.

Note: server support is already implemented for the receiving side of RTSP.

'''Expected results:''' basic servers for network protocols capable of interoperating with third-party clients.

'''Prerequisites:''' C coding skills, basic familiarity with git, network programming.

'''Qualification Task:''' proof-of-concept server for one of the protocol, capable of interacting with a particular client in controlled circumstances; or anything network-related, e.g. fixing a Trac ticket.

'''Mentor:''' [[User:Cigaes|Nicolas George]] (''Cigaes'' in #ffmpeg-devel on Freenode IRC)

'''Backup mentor:''' [[User:Reynaldo|Reynaldo Verdejo]] (''reynaldo'' in #ffmpeg-devel on Freenode IRC, R Verdejo on g mail)

 

= Unmentored Projects =

This is a list of projects that students are encouraged to consider if a mentored project is unavailable or not within the students skill or interests. The student will have to find a mentor for the project. A student can also propose their own project.

== TrueHD encoder ==

'''Description:''' FFmpeg currently does not support encoding to one of the lossless audio formats used on Bluray discs. This task consists of implementing a TrueHD encoder that allows to losslessly encode audio to play it on hardware devices capable of TrueHD decoding.

== Opus decoder ==

[[File:Opus.png|right|link=]]

'''Description:''' Opus decoding is currently supported through the external libopus library
* Write a native decoder, continue working on the existing unfinished implementation
A possible qualification task is to port the existing incomplete decoder to current git head and improve it to show that you are capable of working on this task.

 

== VC-1 interlaced ==

'''Description:''' The FFmpeg VC-1 decoder has improved over the years, but many samples are still not decoded bit-exact and real-world interlaced streams typically show artefacts. This task is difficult.

'''Expected results:'''
* Implement missing parts of interlacing
* Make more reference samples bit-exact

'''Prerequisites:''' C coding skills, basic familiarity with git

'''Qualification Task:''' Find a bug in the current decoder implementation and fix it.

 

== JPEG 2000 ==

'''Description:''' FFmpeg contains an experimental native JPEG 2000 encoder and decoder. Both are missing many features, see also the FFmpeg bug tracker for some unsupported samples. This task is difficult

'''Expected results:''' A jpeg 2000 decoder which can decode most lossy samples without artifacts and lossless samples exactly.

'''Qualification Task:''' Fix an issue (for example from the bug tracker) to show that you are capable of improving the codec implementation.

'''Prerequisites:''' C coding skills, basic familiarity with git, good knowledge of Jpeg-2000

 

== Hardware Accelerated Video Encoding with VA-API ==

[[File:Hardware.jpg|right|link=]]

'''Description:''' FFmpeg already supports hardware accelerated decoding for multiple codecs but still lacks support for hardware accelerated encoding. The aim of the project is to add support for encoding with VA-API specifically, while keeping a generic enough approach in mind so that other hardware accelerators (TI-DSP, CUDA?) could be supported as well. This means that new ''hwaccel'' hooks are needed and two operational modes are possible: either ''(i)'' driver or hardware pack headers themselves, or ''(ii)'' lattitude is left to perform this task at the FFmpeg library level.

'''Expected results:''' Allow MPEG-2 and H.264 encoding with VA-API, while supporting variable bitrate (VBR) by default, and allowing alternate methods like constant bitrate (CBR) or constant QP (CQP) where appropriate or requested.
* MPEG-2 encoding:
** Add basic encoding with I/P frames (handle the ''-g'' option)
** Add support for B frames (handle the ''-bf'' option)
** Add support for constant bitrate (CBR, i.e. ''maxrate == bitrate'' and ''bufsize'' set)
** (Optionally) add support for interlaced contents
* H.264 encoding:
** Add basic encoding with I/P frames (handle the ''-g'' option)
** Add support for B frames (handle the ''-bf'' option)
** Add support for constant bitrate (CBR, i.e. ''maxrate == bitrate'' and ''bufsize'' set)
** Add support for constant QP (CQP, i.e. handle the ''-cqp'' option)
** Add support for more than one reference frame, while providing/using API to query the hardware capabilities
** Work on HRD conformance. May require to write an independent tool to assess that
** (Optionally) add configurability of the motion estimatation method to use. Define new types for HW accelerated encoding with at least two levels/hints for the accelerator.
* FFmpeg applications:
** Define common hwaccel interface for encoding
** Add initial support for hardware accelerated encoding to the ''ffmpeg'' application

'''Prerequisites:''' C coding skills, basic familiarity with git, hardware supporting VA-API for encoding.

'''Qualification Task:''' Anything related to the Hardware Acceleration (hwaccel) API, or to its related users. e.g. add JPEG decoding support with VA-API, etc.

'''Mentor:''' TBA

'''Backup Mentor:''' TBA, possibly Tushar Gohad

 

== H.264 Multiview Video Coding (MVC) ==

[[File:Mmspg-epfl-ch-double-camera.jpg|right|link=]]

'''Description:'''
MVC is used in 3D Blu-ray disks, but FFmpeg is missing a decoder which supports it. The goal of this project is to add support for MVC and 3D-Blu rays.
Since this project also consists of some changes in the current architecture, it is especially important that this project is discussed on the [http://ffmpeg.org/mailman/listinfo/ffmpeg-devel ffmpeg-devel mailing list]. There also exists a [http://article.gmane.org/gmane.comp.video.ffmpeg.devel/174155 patch] and a [https://github.com/kodabb/libav/commits/MVC_orig_clean git branch] which are in rather bad shape but could be used as basis for this project.
This task is difficult because it involves several design decisions that affect third party projects (video players).

'''Expected results:''' Create MVC decoder and add a test for the FFmpeg Automated Testing Environment (FATE).

'''Prerequisites:''' C coding skills, basic familiarity with git. Understanding of H.264

'''Qualification Task:''' Perform work that demonstrates understanding of MVC and that is a subpart of the whole MVC implementation.

'''Mentor:'''

'''Backup mentor:'''

 

== Your Own Project Idea ==

A student can propose a project. Ideas can also be found by browsing bugs and feature requests on our [https://trac.ffmpeg.org/ bug tracker]. The work should last the majority of the GSoC duration, the task must be approved by the developers, and a mentor must be assigned.

Students can discuss an idea in the [http://ffmpeg.org/mailman/listinfo/ffmpeg-devel ffmpeg-devel mailing-list], the #ffmpeg-devel IRC channel, or contact the FFmpeg GSoC admins for more information.

[[Category:FFmpeg]]

FFmpeg SFLC representation

2009-03-27T00:17:48Z

Reynaldo: /* FFmpeg legal representation */

=== FFmpeg legal representation ===

The [http://softwarefreedom.org/ Software Freedom Law Center (SFLC)] represents FFmpeg in legal affairs. To do this, they need a signed contract with individual copyright holders that gives them the right to represent them in legal matters concerning FFmpeg. To have an overview who signed those papers, we are collecting the names of those developers who already signed here.

Add your names in alphabetical order.

* Aurelien Jacobs

Letter reception confirmed by the SFLC:
* Diego Biurrun
* Ronald S. Bultje

Contacted the SFLC but was told they already have enough clients:
* Robert Swain

Contacted the SFLC, got the documents, sent the documents signed but got no confirmation of receipt this far:
* Reynaldo Verdejo

[[Category:FFmpeg]]

FFmpeg Summer Of Code 2008

2008-03-18T22:14:45Z

Reynaldo: /* Finish up a previous incomplete SoC project */

Google is sponsoring their fourth annual [http://code.google.com/soc/2008/ Summer of Code] for the summer of 2008. This entails paying students for working on open source projects. FFmpeg has been a participant in the 2006 and 2007 seasons. Visit the main [[FFmpeg Summer Of Code]] page for information on past seasons.

FFmpeg has been selected to participate in GSoC 2008. This page discusses possible project ideas and status for the Google Summer of Code 2008 season as it pertains to FFmpeg.

The administrator for the FFmpeg Summer of Code is Mike Melanson, a.k.a. [[User:Multimedia Mike|Multimedia Mike]]. His email address is mike -=at=- multimedia.cx.

'''If you are a student''' who wishes to be '''involved with a FFmpeg GSoC''' project, one of the first and best steps you can take is to subscribe to the [https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel FFmpeg development mailing list], sooner rather than later, and indicate your interest. In the past, we have weighted our selection decisions by how involved a prospective student is. And remember to read the part of this page dealing with qualification tasks since you '''absolutely must''' complete a qualification task to be eligible for a FFmpeg SoC project. No qualification task, no project. No exceptions.

== Current Status ==
* '''Next Big Date:''' March 24, 2008: Students may submit applications through Google
* March 17, 2008: Google is scheduled to announce selected projects; ''FFmpeg is selected''
* March 3, 2008: Submitted FFmpeg project application
* February 20, 2008: Created page

== Schedule ==
Official timeline: http://code.google.com/soc/2008/faqs.html#0.1_timeline
* March 3-12, 2008: Open source organizations may apply to the Google Summer of Code program.
* March 17, 2008: Google is scheduled to announce accepted organizations at: http://code.google.com/soc/
* March 24-31, 2008: Students may submit applications for various Google Summer of Code projects.

== Application Process ==
The student application process for 2008 will be as rigorous, if not more so, than in 2007.

[http://code.google.com/opensource/gsoc/2008/faqs.html#0.1_timeline From the formal timeline]:
* March 24, 2008: Student application period opens.
* March 31, 2008: Student application deadline.
* April 11, 2008: Final decisions are made.

All students who wish to be eligible for a GSoC FFmpeg project '''must''' successfully complete a qualification task. A student may submit an application before completing their task and they will have until April 11, 2008 to finish a qualification task. It is ill-advised to wait until the last minute, though. You must ''complete'' the task, which involves getting code approved for submission to source control, which takes many iterations over many days for most people. Further, we like people who show initiative earlier than later.

== 1st Tier Project Proposals ==
1st tier project proposals are project ideas that are reasonably well defined '''AND''' have a mentor volunteered.

==== G.729 Encoder ====
* Specification: http://www.itu.int/rec/T-REC-G.729/e
''Mentor: Benjamin Larsson''

==== G.723.1 Decoder ====
* Specification: http://www.itu.int/rec/T-REC-G.723.1/en
''Mentor: Benjamin Larsson''

==== G.723.1 Encoder ====
* Specification: http://www.itu.int/rec/T-REC-G.723.1/en
''Mentor: Benjamin Larsson''

=== DTS Encoder ===
* Specification: http://wiki.multimedia.cx/index.php?title=Mirror
* Sample files: http://samples.mplayerhq.hu/A-codecs/DTS/
* Qualification: TBD
* Prerequisite: Filterbanks (Sigsys)
* Clearly defined task
* There will be an existing encoder to extend, it will only produce 2 channel 44.1kHz streams.
* Primary goal: Encoder that can produce multi sample rate and multi channel files. Simple rate control. Wav and raw muxing support. Wav dts auto detection when decoding.
* Secondary goal: Techniques from specification implemented, optimal codebook usage, vector quantization, simple psycho acustics.
* Third goal: Advanced psycho acoustics.
''Mentor: Benjamin Larsson''

=== Nellymoser Encoder ===
* Specification: http://svn.mplayerhq.hu/ffmpeg/trunk/libavcodec/nellymoserdec.c?revision=11708&view=markup
* Sample files: http://samples.mplayerhq.hu/A-codecs/Nelly_Moser/
* Qualification: TBD
* Prerequisite: Filterbanks (Sigsys)
* Clearly defined task
* Primary goal: Dumb bitstream compatible encoder
* Secondary goal: Simple psycoacousics implemented
''Mentor: Benjamin Larsson''

=== AAC-LC Encoder ===
* Sample files: http://samples.mplayerhq.hu/A-codecs/AAC/
* Qualification: TBD
* Prerequisite: Filterbanks (Sigsys)
* Clearly defined task
* Primary goal: Dumb bitstream compatible encoder with flexible framework for a serious psychoacoustic implementation
''Mentor: Benjamin Larsson''
''Co-Mentor: Anderas Öman''

=== VP3/Theora Encoder ===
* Clearly defined task
* Primary goal: Encode video sequences such that they can be decoded by a VP3 decoder first, and then a standard Theora decoder.
''Mentor: Mike Melanson''

=== MXF muxer ===
* Specifications: SMPTE 377M
* Clearly defined task
''Mentor: Baptiste Coudurier''

=== MVC decoder ===
* Create an independent FFmpeg decoder for the [[Nokia MVC]] codec
* Very clearly defined task
* ''Mentor: Michael Niedermayer''

=== Apple Lossless Encoder ===
* Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ALAC/
* Decoder: http://svn.mplayerhq.hu/ffmpeg/trunk/libavcodec/alac.c?&view=markup
* Encoder that works on Linux with Wine: http://www.dbpoweramp.com/dmc.htm
* Primary goal: Encode files which will decode losslessly using the FFmpeg ALAC decoder.
* Secondary goal: Make sure encoded files will decode losslessly with iTunes and play on an iPod.
* Reuse as much code as possible from other FFmpeg encoders, namely FLAC since it is a similar codec.
* Specifically, reuse the LPC code from FLAC and make it more generic so it can be shared with various speech codecs as well.
* As time allows, experiment with different parts of the codec to push the boundaries of FFmpeg's decoder and of the format itself.
Also see [[ALAC]] and issue [https://roundup.mplayerhq.hu/roundup/ffmpeg/issue82 #82].

''Mentor: Justin Ruggles''

=== Snow Job ===
This task involves finishing work on the [[Snow]] video codec to bring it to 1.0 quality.
* Document the whole Snow algorithm
* Fix all Snow related bugs on roundup
* faster halfpel interpolation (issue183)
* Try a different transform like an lapped biorthogonal transform instead of the wavelet (this could be better or worse only trying can tell ...)
* anything in [http://svn.mplayerhq.hu/ffmpeg/trunk/doc/TODO?view=co doc/TODO] about Snow and [http://svn.mplayerhq.hu/ffmpeg/trunk/doc/snow.txt?view=co snow.txt/TODO]
* anything else which might improve Snow quality per bitrate
''(The idea here is that the goal would be, do as much as the time allows, though we should decide on some minimum as all above is clearly not doable within the time)

''Mentor: Michael Niedermayer''

=== x264 Improvements ===
This task has been moved to the VideoLan project, and can be found [http://wiki.videolan.org/SoC_x264 here].

== 2nd Tier Project Proposals ==
All that separates these proposals from their 1st tier brethren is a mentor. If you are particularly passionate about one of these tasks, perhaps you should attach your name to it. ''(Email me if you want to discuss it or need access to the Wiki. --[[User:Multimedia Mike|Multimedia Mike]] 21:58, 1 March 2008 (EST))''

==== GUI for FFmpeg ====
Build a gui for the libs of FFmpeg. The main objective in this task is to extent the codecs and formats to support querying of features and good defaults. The actual GUI should just be a simple skeleton with support for encoding of multiple files. Most of the work will be done in the libs.

==== Port FFmpeg to Visual Studio ====
Create a full working port including inline assembly.

==== Optimize FFT routines ====
Port djbfft and rework the fft framework in FFmpeg. This task can include a fixedpoint port and SIMD optimizations.

==== GSM Decoder ====
* Specification + sample implementation: http://kbs.cs.tu-berlin.de/~jutta/toast.html
* Samples: http://samples.mplayerhq.hu/A-codecs/GSM/
Also see [[GSM]].

==== AMR-WB Decoder ====
* Specification: http://www.3gpp.org/ftp/Specs/html-info/26-series.htm
* Samples: http://samples.mplayerhq.hu/A-codecs/amr/
Also see [[AMR]].

==== AMR-NB Encoder ====
* Specification: http://www.3gpp.org/ftp/Specs/html-info/26-series.htm
* Samples: http://samples.mplayerhq.hu/A-codecs/amr/
Also see [[AMR]].

==== Speex Decoder ====
* Specification: http://speex.org/docs/
* Samples: http://samples.mplayerhq.hu/A-codecs/speex/
Also see [[Speex]].

=== WMV3 Encoder ===
* Clearly defined task
* Primary goal: Encode video sequences such that they can be decoded by a Windows Media player.

This could either be done by improving [[Interesting Patches#WMV3 encoder by Denis Fortin|this patch]] or by writing the encoder from scratch.

=== Improve Ratecontrol ===
* Primary goal: Per Macroblock ratecontrol.
* Secondary goals: very regular one pass CBR ratecontrol (streaming), better Scene cut detection/B frames decision.

=== Better handling of audio in libavcodec ===
* Info: http://wiki.multimedia.cx/index.php?title=Ffmpeg_audio_api
* Loosely defined task

=== LGPL reimplementation of GPL sws_scale parts ===
* Loosely defined task
* Primary goal: LGPL licensed sws_scale
* Secondary goal: removal of lavc scaler

=== Freeform Proposal ===
If you think you have a good idea for a FFmpeg Summer of Code project, propose it on the [https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel FFmpeg development mailing list]. We will discuss it from there.

== Qualification Tasks ==
Many students apply for the Google Summer of Code and wish to work on a sexy multimedia project such as FFmpeg. All students will claim to be hard workers but we need a method of determining which students have a higher probability for success. Thus, we developed the qualification system during the 2007 season and will be enforcing the same system this year. A student must successfully complete a qualification task in order to be considered for an FFmpeg SoC project. In doing so, a student demonstrates that they:

* are willing to commit some time during the Summer of Code application review period in order to prove themselves
* can code C satisfactorily and with the same general style expected of the FFmpeg codebase
* can wrap their head around the code base
* can interact with the FFmpeg development mailing list
* can accept feedback and revise the code until it is suitable for inclusion in the main code base

'''Frequent Objection #1:''' ''But I don't have time to do a qualification task!'' Then how do we know you will have time to work on your task during the summer? The qualification tasks are selected to be fairly trivial by FFmpeg standards and should not be too difficult for a prospective FFmpeg contributor. If they ''are'' too difficult, maybe FFmpeg is not the project for you. Also, be encouraged by the fact that the app review period comes after the application submission deadline; i.e., you can work on a qualification task ''after'' you submit an application for FFmpeg. But you will not be considered for an SoC project slot unless you have satisfactorily completed a qualification task.

'''Process:''' If you are interested in applying for FFmpeg's Summer of Code and, by extension, interested in working on a qualification task, the first step is to subscribe to the [https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel FFmpeg development mailing list] and indicate your interest and which project you plan to work on.

=== Finish up a previous incomplete SoC project ===

Several SoC projects from previous years have not yet made it into FFmpeg. Taking any of them and finishing them up to the point that they can be included should make for a good qualification task. Check out the [[FFmpeg Summer Of Code]] overview page and look for the unfinished projects, like AMR-NB, QCELP, Dirac, TS muxer, JPEG 2000.

* Bartlomiej Wolowiec is working on finishing the EAC3 decoder [http://lists.mplayerhq.hu/pipermail/ffmpeg-soc/2008-March/002745.html].

* A G BHATT is working on [[FFmpeg Summer Of Code#JPEG 2000 Encoder and Decoder|JPEG 2000 decoder]] [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043754.html].

* Zhentan Feng is working on the [[FFmpeg Summer Of Code#TS Muxer|TS Muxer]] [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043773.html].

* Reynaldo H. Verdejo Pinochet is working on the [[FFmpeg Summer Of Code#QCELP Decoder|QCELP Decoder]] [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043806.html].

=== Generic Colorspace system ===
This task involves adding support more than 8 bits per component (Y on 10 bits, U on 10 bits, V on 10 bits for example)
and generic simple conversion to other colorspaces.

''Does this have to do with revising FFmpeg's infrastructure? If so, then it doesn't feel like a qualification task. If it's something simpler, then the vague description does not convey that simplicity. Please expound.'' --[[User:Multimedia Mike|Multimedia Mike]] 12:56, 25 February 2008 (EST)

''I don't think so, extending PixFmt to extended structure with finegrained description like depth, range values, colorspace, sample period, and write generic simple conversion from all formats to all others, like suggested by Michael on the mailing list. Conversion routine can be a good qualification task for video encoders/decoders. What do you think ?
--[[User:Bcoudurier|Baptiste Coudurier]] 00:30, 29 February 2008 (EST)

=== Cleanup of MLP decoder ===
This task involves adding a decoder to FFmpeg to play [[Meridian Lossless Packing|MLP]] audio data. The hard work has already been done; now a volunteer needs to take the existing decoder patch and make it satisfactory for inclusion into the codebase. MLP samples referenced from the [[Meridian Lossless Packing|MLP]] Wiki page.

Latest version of the MLP patch: http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-January/040234.html

And the comments: http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-January/040251.html

Claimed by: Andy Gocke

=== Support PB frame mode for H.263i ===
Details are in the issue tracker: http://roundup.mplayerhq.hu/roundup/ffmpeg/issue27

=== Patch cleanup for MPEG 1 & 2 optimizations ===
Details are in the issue tracker: http://roundup.mplayerhq.hu/roundup/ffmpeg/issue100

=== Implement a Vivo demuxer for FFmpeg ===
Implement an FFmpeg demuxer for the [[Vivo]] file format. The best reference for understanding the format would be MPlayer's [http://svn.mplayerhq.hu/mplayer/trunk/libmpdemux/demux_viv.c?view=markup existing .viv demuxer].

This task corresponds to issue 99: http://roundup.mplayerhq.hu/roundup/ffmpeg/issue99

''I am ready to help out with understanding MPlayer's demuxer, esp. MPlayer API stuff if necessary.
--[[User:Reimar|Reimar]] 15:46, 1 March 2008 (EST)

* Marcondes Ricarte is working on this [http://lists.mplayerhq.hu/pipermail/ffmpeg-soc/2008-March/002704.html]

=== Optimal Huffman tables for (M)JPEG ===
This task is outlined at http://guru.multimedia.cx/small-tasks-for-ffmpeg/ and is tracked in the issue tracker: http://roundup.mplayerhq.hu/roundup/ffmpeg/issue267

* Deep Pal [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043547.html asked] this task to be assigned to him in the ffmpeg-devel mailing list.

=== RL2 Playback System ===
This task is to implement an FFmpeg playback subsystem for [[RL2]] files. This will entail writing a new file demuxer and video decoder (the audio is already uncompressed), both of which are trivial by FFmpeg standards. [[RL2|The RL2 page]] contains the specs necessary to complete this task and points to downloadable samples.

:''Sascha Sommer sent a [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043598.html patch] to implement this to ffmpeg-devel.''

=== YOP Playback System ===
This task is to implement an FFmpeg playback subsystem for [[Psygnosis YOP]] files. This will entail writing a new file demuxer and video decoder, both of which are trivial by FFmpeg standards. [[Psygnosis YOP|The Psygnosis YOP page]] contains the specs necessary to complete this task and points to downloadable samples.

* Claimed by Indrani

=== BFI Playback System ===
This task is to implement an FFmpeg playback subsystem for [[BFI]] files. This will entail writing a new file demuxer and video decoder (the audio is already uncompressed), both of which are trivial by FFmpeg standards. [[BFI|The BFI page]] contains the specs necessary to complete this task and points to downloadable samples.

=== M95 Playback System ===
This task is to implement an FFmpeg playback subsystem for [[M95]] files. This will entail writing a new file demuxer and video decoder (the audio is already uncompressed), both of which are trivial by FFmpeg standards. [[M95|The M95 page]] contains the specs necessary to complete this task and points to downloadable samples.
:''Claimed by [[User:kdubois]]''

=== SSE2 iDCT Optimization ===
Incorporate an invert discrete cosine transform for SSE2-capable CPUs. The hardest work is already done-- dig up Intel's AP-945 application programming note which will spell out precisely how to do this. Mostly, this involves adapting the ASM code for gcc AT&T syntax.

:''I will be working on this.'' - [[User:Astrange|Alexander Strange]]

=== Apple RPZA encoder ===
Clean up the patch for svn inclusion. The current code can be found from here "[[Interesting Patches]]".

=== IFF demuxer ===
Implement demuxing of 8svx audio.

=== Interesting Patches ===
There is a growing backlog of "[[Interesting Patches]]" for FFmpeg tracked on this Wiki. Each one requires a volunteer to task the initiative to clean up the patch to the satisfaction of the project leaders so that it can finally be included.

=== Some bug on the bugtracker ===
From this page you can find the bugtracker: http://ffmpeg.mplayerhq.hu/bugreports.html
Some issues can qualify as a qualification task.

=== Legacy Tasks ===
Many tasks were suggested during the 2007 season. Any task that is not marked as '''completed''' is probably fair game, but ask on the list, just to be sure: http://wiki.multimedia.cx/index.php?title=FFmpeg_Summer_Of_Code_2007#Qualification_tasks

=== Freeform Tasks ===
If you have an idea for a simple task, come and discuss it on the [https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel development mailing list] and the devs might approve it.

[[Category:FFmpeg]]

FFmpeg Summer Of Code 2008

2008-03-18T22:13:55Z

Reynaldo: /* Finish up a previous incomplete SoC project */

Google is sponsoring their fourth annual [http://code.google.com/soc/2008/ Summer of Code] for the summer of 2008. This entails paying students for working on open source projects. FFmpeg has been a participant in the 2006 and 2007 seasons. Visit the main [[FFmpeg Summer Of Code]] page for information on past seasons.

FFmpeg has been selected to participate in GSoC 2008. This page discusses possible project ideas and status for the Google Summer of Code 2008 season as it pertains to FFmpeg.

The administrator for the FFmpeg Summer of Code is Mike Melanson, a.k.a. [[User:Multimedia Mike|Multimedia Mike]]. His email address is mike -=at=- multimedia.cx.

'''If you are a student''' who wishes to be '''involved with a FFmpeg GSoC''' project, one of the first and best steps you can take is to subscribe to the [https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel FFmpeg development mailing list], sooner rather than later, and indicate your interest. In the past, we have weighted our selection decisions by how involved a prospective student is. And remember to read the part of this page dealing with qualification tasks since you '''absolutely must''' complete a qualification task to be eligible for a FFmpeg SoC project. No qualification task, no project. No exceptions.

== Current Status ==
* '''Next Big Date:''' March 24, 2008: Students may submit applications through Google
* March 17, 2008: Google is scheduled to announce selected projects; ''FFmpeg is selected''
* March 3, 2008: Submitted FFmpeg project application
* February 20, 2008: Created page

== Schedule ==
Official timeline: http://code.google.com/soc/2008/faqs.html#0.1_timeline
* March 3-12, 2008: Open source organizations may apply to the Google Summer of Code program.
* March 17, 2008: Google is scheduled to announce accepted organizations at: http://code.google.com/soc/
* March 24-31, 2008: Students may submit applications for various Google Summer of Code projects.

== Application Process ==
The student application process for 2008 will be as rigorous, if not more so, than in 2007.

[http://code.google.com/opensource/gsoc/2008/faqs.html#0.1_timeline From the formal timeline]:
* March 24, 2008: Student application period opens.
* March 31, 2008: Student application deadline.
* April 11, 2008: Final decisions are made.

All students who wish to be eligible for a GSoC FFmpeg project '''must''' successfully complete a qualification task. A student may submit an application before completing their task and they will have until April 11, 2008 to finish a qualification task. It is ill-advised to wait until the last minute, though. You must ''complete'' the task, which involves getting code approved for submission to source control, which takes many iterations over many days for most people. Further, we like people who show initiative earlier than later.

== 1st Tier Project Proposals ==
1st tier project proposals are project ideas that are reasonably well defined '''AND''' have a mentor volunteered.

==== G.729 Encoder ====
* Specification: http://www.itu.int/rec/T-REC-G.729/e
''Mentor: Benjamin Larsson''

==== G.723.1 Decoder ====
* Specification: http://www.itu.int/rec/T-REC-G.723.1/en
''Mentor: Benjamin Larsson''

==== G.723.1 Encoder ====
* Specification: http://www.itu.int/rec/T-REC-G.723.1/en
''Mentor: Benjamin Larsson''

=== DTS Encoder ===
* Specification: http://wiki.multimedia.cx/index.php?title=Mirror
* Sample files: http://samples.mplayerhq.hu/A-codecs/DTS/
* Qualification: TBD
* Prerequisite: Filterbanks (Sigsys)
* Clearly defined task
* There will be an existing encoder to extend, it will only produce 2 channel 44.1kHz streams.
* Primary goal: Encoder that can produce multi sample rate and multi channel files. Simple rate control. Wav and raw muxing support. Wav dts auto detection when decoding.
* Secondary goal: Techniques from specification implemented, optimal codebook usage, vector quantization, simple psycho acustics.
* Third goal: Advanced psycho acoustics.
''Mentor: Benjamin Larsson''

=== Nellymoser Encoder ===
* Specification: http://svn.mplayerhq.hu/ffmpeg/trunk/libavcodec/nellymoserdec.c?revision=11708&view=markup
* Sample files: http://samples.mplayerhq.hu/A-codecs/Nelly_Moser/
* Qualification: TBD
* Prerequisite: Filterbanks (Sigsys)
* Clearly defined task
* Primary goal: Dumb bitstream compatible encoder
* Secondary goal: Simple psycoacousics implemented
''Mentor: Benjamin Larsson''

=== AAC-LC Encoder ===
* Sample files: http://samples.mplayerhq.hu/A-codecs/AAC/
* Qualification: TBD
* Prerequisite: Filterbanks (Sigsys)
* Clearly defined task
* Primary goal: Dumb bitstream compatible encoder with flexible framework for a serious psychoacoustic implementation
''Mentor: Benjamin Larsson''
''Co-Mentor: Anderas Öman''

=== VP3/Theora Encoder ===
* Clearly defined task
* Primary goal: Encode video sequences such that they can be decoded by a VP3 decoder first, and then a standard Theora decoder.
''Mentor: Mike Melanson''

=== MXF muxer ===
* Specifications: SMPTE 377M
* Clearly defined task
''Mentor: Baptiste Coudurier''

=== MVC decoder ===
* Create an independent FFmpeg decoder for the [[Nokia MVC]] codec
* Very clearly defined task
* ''Mentor: Michael Niedermayer''

=== Apple Lossless Encoder ===
* Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ALAC/
* Decoder: http://svn.mplayerhq.hu/ffmpeg/trunk/libavcodec/alac.c?&view=markup
* Encoder that works on Linux with Wine: http://www.dbpoweramp.com/dmc.htm
* Primary goal: Encode files which will decode losslessly using the FFmpeg ALAC decoder.
* Secondary goal: Make sure encoded files will decode losslessly with iTunes and play on an iPod.
* Reuse as much code as possible from other FFmpeg encoders, namely FLAC since it is a similar codec.
* Specifically, reuse the LPC code from FLAC and make it more generic so it can be shared with various speech codecs as well.
* As time allows, experiment with different parts of the codec to push the boundaries of FFmpeg's decoder and of the format itself.
Also see [[ALAC]] and issue [https://roundup.mplayerhq.hu/roundup/ffmpeg/issue82 #82].

''Mentor: Justin Ruggles''

=== Snow Job ===
This task involves finishing work on the [[Snow]] video codec to bring it to 1.0 quality.
* Document the whole Snow algorithm
* Fix all Snow related bugs on roundup
* faster halfpel interpolation (issue183)
* Try a different transform like an lapped biorthogonal transform instead of the wavelet (this could be better or worse only trying can tell ...)
* anything in [http://svn.mplayerhq.hu/ffmpeg/trunk/doc/TODO?view=co doc/TODO] about Snow and [http://svn.mplayerhq.hu/ffmpeg/trunk/doc/snow.txt?view=co snow.txt/TODO]
* anything else which might improve Snow quality per bitrate
''(The idea here is that the goal would be, do as much as the time allows, though we should decide on some minimum as all above is clearly not doable within the time)

''Mentor: Michael Niedermayer''

=== x264 Improvements ===
This task has been moved to the VideoLan project, and can be found [http://wiki.videolan.org/SoC_x264 here].

== 2nd Tier Project Proposals ==
All that separates these proposals from their 1st tier brethren is a mentor. If you are particularly passionate about one of these tasks, perhaps you should attach your name to it. ''(Email me if you want to discuss it or need access to the Wiki. --[[User:Multimedia Mike|Multimedia Mike]] 21:58, 1 March 2008 (EST))''

==== GUI for FFmpeg ====
Build a gui for the libs of FFmpeg. The main objective in this task is to extent the codecs and formats to support querying of features and good defaults. The actual GUI should just be a simple skeleton with support for encoding of multiple files. Most of the work will be done in the libs.

==== Port FFmpeg to Visual Studio ====
Create a full working port including inline assembly.

==== Optimize FFT routines ====
Port djbfft and rework the fft framework in FFmpeg. This task can include a fixedpoint port and SIMD optimizations.

==== GSM Decoder ====
* Specification + sample implementation: http://kbs.cs.tu-berlin.de/~jutta/toast.html
* Samples: http://samples.mplayerhq.hu/A-codecs/GSM/
Also see [[GSM]].

==== AMR-WB Decoder ====
* Specification: http://www.3gpp.org/ftp/Specs/html-info/26-series.htm
* Samples: http://samples.mplayerhq.hu/A-codecs/amr/
Also see [[AMR]].

==== AMR-NB Encoder ====
* Specification: http://www.3gpp.org/ftp/Specs/html-info/26-series.htm
* Samples: http://samples.mplayerhq.hu/A-codecs/amr/
Also see [[AMR]].

==== Speex Decoder ====
* Specification: http://speex.org/docs/
* Samples: http://samples.mplayerhq.hu/A-codecs/speex/
Also see [[Speex]].

=== WMV3 Encoder ===
* Clearly defined task
* Primary goal: Encode video sequences such that they can be decoded by a Windows Media player.

This could either be done by improving [[Interesting Patches#WMV3 encoder by Denis Fortin|this patch]] or by writing the encoder from scratch.

=== Improve Ratecontrol ===
* Primary goal: Per Macroblock ratecontrol.
* Secondary goals: very regular one pass CBR ratecontrol (streaming), better Scene cut detection/B frames decision.

=== Better handling of audio in libavcodec ===
* Info: http://wiki.multimedia.cx/index.php?title=Ffmpeg_audio_api
* Loosely defined task

=== LGPL reimplementation of GPL sws_scale parts ===
* Loosely defined task
* Primary goal: LGPL licensed sws_scale
* Secondary goal: removal of lavc scaler

=== Freeform Proposal ===
If you think you have a good idea for a FFmpeg Summer of Code project, propose it on the [https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel FFmpeg development mailing list]. We will discuss it from there.

== Qualification Tasks ==
Many students apply for the Google Summer of Code and wish to work on a sexy multimedia project such as FFmpeg. All students will claim to be hard workers but we need a method of determining which students have a higher probability for success. Thus, we developed the qualification system during the 2007 season and will be enforcing the same system this year. A student must successfully complete a qualification task in order to be considered for an FFmpeg SoC project. In doing so, a student demonstrates that they:

* are willing to commit some time during the Summer of Code application review period in order to prove themselves
* can code C satisfactorily and with the same general style expected of the FFmpeg codebase
* can wrap their head around the code base
* can interact with the FFmpeg development mailing list
* can accept feedback and revise the code until it is suitable for inclusion in the main code base

'''Frequent Objection #1:''' ''But I don't have time to do a qualification task!'' Then how do we know you will have time to work on your task during the summer? The qualification tasks are selected to be fairly trivial by FFmpeg standards and should not be too difficult for a prospective FFmpeg contributor. If they ''are'' too difficult, maybe FFmpeg is not the project for you. Also, be encouraged by the fact that the app review period comes after the application submission deadline; i.e., you can work on a qualification task ''after'' you submit an application for FFmpeg. But you will not be considered for an SoC project slot unless you have satisfactorily completed a qualification task.

'''Process:''' If you are interested in applying for FFmpeg's Summer of Code and, by extension, interested in working on a qualification task, the first step is to subscribe to the [https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel FFmpeg development mailing list] and indicate your interest and which project you plan to work on.

=== Finish up a previous incomplete SoC project ===

Several SoC projects from previous years have not yet made it into FFmpeg. Taking any of them and finishing them up to the point that they can be included should make for a good qualification task. Check out the [[FFmpeg Summer Of Code]] overview page and look for the unfinished projects, like AMR-NB, QCELP, Dirac, TS muxer, JPEG 2000.

* Bartlomiej Wolowiec is working on finishing the EAC3 decoder [http://lists.mplayerhq.hu/pipermail/ffmpeg-soc/2008-March/002745.html].

* A G BHATT is working on [[FFmpeg Summer Of Code#JPEG 2000 Encoder and Decoder|JPEG 2000 decoder]] [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043754.html].

* Zhentan Feng is working on the [[FFmpeg Summer Of Code#TS Muxer|TS Muxer]] [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043773.html].

* Reynaldo H. Verdejo Pinochet is working on the [[FFmpeg Summer Of Code#QCELP Decoder]] [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043806.html].

=== Generic Colorspace system ===
This task involves adding support more than 8 bits per component (Y on 10 bits, U on 10 bits, V on 10 bits for example)
and generic simple conversion to other colorspaces.

''Does this have to do with revising FFmpeg's infrastructure? If so, then it doesn't feel like a qualification task. If it's something simpler, then the vague description does not convey that simplicity. Please expound.'' --[[User:Multimedia Mike|Multimedia Mike]] 12:56, 25 February 2008 (EST)

''I don't think so, extending PixFmt to extended structure with finegrained description like depth, range values, colorspace, sample period, and write generic simple conversion from all formats to all others, like suggested by Michael on the mailing list. Conversion routine can be a good qualification task for video encoders/decoders. What do you think ?
--[[User:Bcoudurier|Baptiste Coudurier]] 00:30, 29 February 2008 (EST)

=== Cleanup of MLP decoder ===
This task involves adding a decoder to FFmpeg to play [[Meridian Lossless Packing|MLP]] audio data. The hard work has already been done; now a volunteer needs to take the existing decoder patch and make it satisfactory for inclusion into the codebase. MLP samples referenced from the [[Meridian Lossless Packing|MLP]] Wiki page.

Latest version of the MLP patch: http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-January/040234.html

And the comments: http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-January/040251.html

Claimed by: Andy Gocke

=== Support PB frame mode for H.263i ===
Details are in the issue tracker: http://roundup.mplayerhq.hu/roundup/ffmpeg/issue27

=== Patch cleanup for MPEG 1 & 2 optimizations ===
Details are in the issue tracker: http://roundup.mplayerhq.hu/roundup/ffmpeg/issue100

=== Implement a Vivo demuxer for FFmpeg ===
Implement an FFmpeg demuxer for the [[Vivo]] file format. The best reference for understanding the format would be MPlayer's [http://svn.mplayerhq.hu/mplayer/trunk/libmpdemux/demux_viv.c?view=markup existing .viv demuxer].

This task corresponds to issue 99: http://roundup.mplayerhq.hu/roundup/ffmpeg/issue99

''I am ready to help out with understanding MPlayer's demuxer, esp. MPlayer API stuff if necessary.
--[[User:Reimar|Reimar]] 15:46, 1 March 2008 (EST)

* Marcondes Ricarte is working on this [http://lists.mplayerhq.hu/pipermail/ffmpeg-soc/2008-March/002704.html]

=== Optimal Huffman tables for (M)JPEG ===
This task is outlined at http://guru.multimedia.cx/small-tasks-for-ffmpeg/ and is tracked in the issue tracker: http://roundup.mplayerhq.hu/roundup/ffmpeg/issue267

* Deep Pal [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043547.html asked] this task to be assigned to him in the ffmpeg-devel mailing list.

=== RL2 Playback System ===
This task is to implement an FFmpeg playback subsystem for [[RL2]] files. This will entail writing a new file demuxer and video decoder (the audio is already uncompressed), both of which are trivial by FFmpeg standards. [[RL2|The RL2 page]] contains the specs necessary to complete this task and points to downloadable samples.

:''Sascha Sommer sent a [http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-March/043598.html patch] to implement this to ffmpeg-devel.''

=== YOP Playback System ===
This task is to implement an FFmpeg playback subsystem for [[Psygnosis YOP]] files. This will entail writing a new file demuxer and video decoder, both of which are trivial by FFmpeg standards. [[Psygnosis YOP|The Psygnosis YOP page]] contains the specs necessary to complete this task and points to downloadable samples.

* Claimed by Indrani

=== BFI Playback System ===
This task is to implement an FFmpeg playback subsystem for [[BFI]] files. This will entail writing a new file demuxer and video decoder (the audio is already uncompressed), both of which are trivial by FFmpeg standards. [[BFI|The BFI page]] contains the specs necessary to complete this task and points to downloadable samples.

=== M95 Playback System ===
This task is to implement an FFmpeg playback subsystem for [[M95]] files. This will entail writing a new file demuxer and video decoder (the audio is already uncompressed), both of which are trivial by FFmpeg standards. [[M95|The M95 page]] contains the specs necessary to complete this task and points to downloadable samples.
:''Claimed by [[User:kdubois]]''

=== SSE2 iDCT Optimization ===
Incorporate an invert discrete cosine transform for SSE2-capable CPUs. The hardest work is already done-- dig up Intel's AP-945 application programming note which will spell out precisely how to do this. Mostly, this involves adapting the ASM code for gcc AT&T syntax.

:''I will be working on this.'' - [[User:Astrange|Alexander Strange]]

=== Apple RPZA encoder ===
Clean up the patch for svn inclusion. The current code can be found from here "[[Interesting Patches]]".

=== IFF demuxer ===
Implement demuxing of 8svx audio.

=== Interesting Patches ===
There is a growing backlog of "[[Interesting Patches]]" for FFmpeg tracked on this Wiki. Each one requires a volunteer to task the initiative to clean up the patch to the satisfaction of the project leaders so that it can finally be included.

=== Some bug on the bugtracker ===
From this page you can find the bugtracker: http://ffmpeg.mplayerhq.hu/bugreports.html
Some issues can qualify as a qualification task.

=== Legacy Tasks ===
Many tasks were suggested during the 2007 season. Any task that is not marked as '''completed''' is probably fair game, but ask on the list, just to be sure: http://wiki.multimedia.cx/index.php?title=FFmpeg_Summer_Of_Code_2007#Qualification_tasks

=== Freeform Tasks ===
If you have an idea for a simple task, come and discuss it on the [https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel development mailing list] and the devs might approve it.

[[Category:FFmpeg]]

ACT

2006-12-27T05:21:09Z

Reynaldo:

ACT is a low complexity speech compression codec

[[Category:Audio Codecs]]
[[Category:Undiscovered Audio Codecs]]

ACT

2006-12-27T05:18:49Z

Reynaldo:

ACT is a low complexity speech compression codec

[[Category:Undiscovered Codecs]]
[[Category:Audio Codecs]]

ACT

2006-12-27T05:16:24Z

Reynaldo:

ACT is a low complexity speech compression codec

MTV

2006-12-27T05:13:20Z

Reynaldo: /* Software players that support MTV and AMV playback */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
'''MTV''' is file format supposedly created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP4 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "'''MP4 Player'''" or "'''PMP'''", for '''P'''ersonal '''M'''edia '''P'''layer) are flash-based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China and capable of displaying images, videos, and text files. Although commonly called MP4 players, are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to proprietary formats such as this one and [[AMV]].

==MTV File Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing [[MP3]] audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats, as in fact very little "encoding" is actually done.

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necessarily aligned on block boundaries and each one of them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream. The first 12 bytes of each audio subblock is padding data and is always set to 0. Image data, on the other hand, is perfectly contained in each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the MP3 hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image frame data.

{| class="wikitable" style="text-align:right"
![[Image:mtv_overview.png]]
|}

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frames/s, 22050 samples/s mono sound : 80 MB (approx) The audio is 22050 samples/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG-2 PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
The software available in April 2006 allows screen sizes of 94x64, 128x96 and 128x128 pixels, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*[[FFmpeg]]'s [[ffplay]] supports MTV playback

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-12-27T05:12:18Z

Reynaldo: /* MTV File Format */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
'''MTV''' is file format supposedly created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP4 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "'''MP4 Player'''" or "'''PMP'''", for '''P'''ersonal '''M'''edia '''P'''layer) are flash-based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China and capable of displaying images, videos, and text files. Although commonly called MP4 players, are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to proprietary formats such as this one and [[AMV]].

==MTV File Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing [[MP3]] audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats, as in fact very little "encoding" is actually done.

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necessarily aligned on block boundaries and each one of them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream. The first 12 bytes of each audio subblock is padding data and is always set to 0. Image data, on the other hand, is perfectly contained in each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the MP3 hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image frame data.

{| class="wikitable" style="text-align:right"
![[Image:mtv_overview.png]]
|}

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frames/s, 22050 samples/s mono sound : 80 MB (approx) The audio is 22050 samples/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG-2 PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
The software available in April 2006 allows screen sizes of 94x64, 128x96 and 128x128 pixels, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*[[FFmpeg]]'s [[ffplay]] supports MTV playback
*[[MPlayer]] supports MTV playback through FFmpeg's libavformat

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-12-27T05:11:35Z

Reynaldo: /* MTV File Format */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
'''MTV''' is file format supposedly created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP4 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "'''MP4 Player'''" or "'''PMP'''", for '''P'''ersonal '''M'''edia '''P'''layer) are flash-based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China and capable of displaying images, videos, and text files. Although commonly called MP4 players, are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to proprietary formats such as this one and [[AMV]].

==MTV File Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing [[MP3]] audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats, as in fact very little "encoding" is actually done.

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necessarily aligned on block boundaries and each one of them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream. The first 12 bytes of each audio subblock is padding data and is always set to 0. Image data, on the other hand, is perfectly contained in each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the MP3 hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information.

{| class="wikitable" style="text-align:right"
![[Image:mtv_overview.png]]
|}

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frames/s, 22050 samples/s mono sound : 80 MB (approx) The audio is 22050 samples/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG-2 PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
The software available in April 2006 allows screen sizes of 94x64, 128x96 and 128x128 pixels, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*[[FFmpeg]]'s [[ffplay]] supports MTV playback
*[[MPlayer]] supports MTV playback through FFmpeg's libavformat

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-12-27T05:09:40Z

Reynaldo: /* MTV video origin and history */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
'''MTV''' is file format supposedly created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP4 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "'''MP4 Player'''" or "'''PMP'''", for '''P'''ersonal '''M'''edia '''P'''layer) are flash-based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China and capable of displaying images, videos, and text files. Although commonly called MP4 players, are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to proprietary formats such as this one and [[AMV]].

==MTV File Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing [[MP3]] audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats, as in fact very little "encoding" is actually done.

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necessarily aligned on block boundaries and each one of them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream. The first 12 bytes of each audio subblock is padding data and is always set to 0. Image data, on the other hand, is perfectly contained in each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the MP3 hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

{| class="wikitable" style="text-align:right"
![[Image:mtv_overview.png]]
|}

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frames/s, 22050 samples/s mono sound : 80 MB (approx) The audio is 22050 samples/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG-2 PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
The software available in April 2006 allows screen sizes of 94x64, 128x96 and 128x128 pixels, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*[[FFmpeg]]'s [[ffplay]] supports MTV playback
*[[MPlayer]] supports MTV playback through FFmpeg's libavformat

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-12-27T05:08:58Z

Reynaldo: /* MTV video origin and history */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
'''MTV''' is file format supposedly created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP4 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "'''MP4 Player'''" or "'''PMP'''", for '''P'''ersonal '''M'''edia '''P'''layer) are flash-based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China and capable of viewing images, videos, and text files. Although commonly called MP4 players, are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to proprietary formats such as this one and [[AMV]].

==MTV File Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing [[MP3]] audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats, as in fact very little "encoding" is actually done.

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necessarily aligned on block boundaries and each one of them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream. The first 12 bytes of each audio subblock is padding data and is always set to 0. Image data, on the other hand, is perfectly contained in each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the MP3 hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

{| class="wikitable" style="text-align:right"
![[Image:mtv_overview.png]]
|}

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frames/s, 22050 samples/s mono sound : 80 MB (approx) The audio is 22050 samples/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG-2 PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
The software available in April 2006 allows screen sizes of 94x64, 128x96 and 128x128 pixels, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*[[FFmpeg]]'s [[ffplay]] supports MTV playback
*[[MPlayer]] supports MTV playback through FFmpeg's libavformat

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

Talk:AMV

2006-12-27T05:02:27Z

Reynaldo: Aclaration

is [[AMV]] a file-format or a video-codec?, I thought AMV was the file-format and [[MTV]] was the video-codec?!, both extentions (.amv and .mtv) can be found on [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player MP4/MTV-Player] download sites :/

Also see MTV discussion http://wiki.multimedia.cx/index.php?title=Talk:MTV

== Aclaration ==

It is a file format used for carrying compressed video/audio streams. so is MTV but the latter while carrying compresed audio just uses raw rgb for the video.

AMV

2006-12-27T04:59:21Z

Reynaldo:

* Extension: amv
* Samples: [http://www.mympxplayer.org/sample-videos-dc7.html] and [http://samples.mplayerhq.hu/amv/] 

==AMV video origin and history==
Little is known about the history of the '''AMV''' file format other than it been used by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] and been suposedly created to allow video playback capabilities on inexpensive and low end equipment without increasing the cost of those players with the license royalties and more processor power needed for other more complex format/codec pairs.

==AMV Video File Format==
AMV files contain a [[RIFF]] packed stream of video ([[Talk:AMV|video codec?]]) and [[MP3]] encoded audio.
 
When playing AMV formats, there is clearly some image de/compression taking place, as can be demonstrated by a simple calculation (see the [[MTV|MTV Video Format]] article). The image compression is, however, low by modern standards (around 4 pixels/byte, compared with over 10 pixels/byte in the [[MPEG-2]] DVD-Video standard). With a resolution of 128 x 96, and a frame rate of 12 fps, a 30 minute file will be around 80 MegaByte in size. 

==AMV and MTV encoding/transcoding information and utilities==
* [http://www.s1mp3.org/wiki/index.php/Video_encoding AMV encoding tips]
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)] 

==Software players that support AMV and MTV playback==
*Unknown
 

==Hardware players that support AMV and MTV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players]. 

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

 

[[Category:Video Codecs]]
[[Category:Undiscovered Video Codecs]]

AMV

2006-12-27T04:57:29Z

Reynaldo: /* AMV video origin and history */

* Extension: amv (or [[mtv]])
* Samples: [http://www.mympxplayer.org/sample-videos-dc7.html] and [http://samples.mplayerhq.hu/amv/] 

==AMV video origin and history==
Little is known about the history of the '''AMV''' file format other than it been used by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] and been suposedly created to allow video playback capabilities on inexpensive and low end equipment without increasing the cost of those players with the license royalties and more processor power needed for other more complex format/codec pairs.

==AMV Video File Format==
AMV files contain a [[RIFF]] packed stream of video ([[Talk:AMV|video codec?]]) and [[MP3]] encoded audio.
 
When playing AMV formats, there is clearly some image de/compression taking place, as can be demonstrated by a simple calculation (see the [[MTV|MTV Video Format]] article). The image compression is, however, low by modern standards (around 4 pixels/byte, compared with over 10 pixels/byte in the [[MPEG-2]] DVD-Video standard). With a resolution of 128 x 96, and a frame rate of 12 fps, a 30 minute file will be around 80 MegaByte in size. 

==AMV and MTV encoding/transcoding information and utilities==
* [http://www.s1mp3.org/wiki/index.php/Video_encoding AMV encoding tips]
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)] 

==Software players that support AMV and MTV playback==
*Unknown
 

==Hardware players that support AMV and MTV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players]. 

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

 

[[Category:Video Codecs]]
[[Category:Undiscovered Video Codecs]]

AMV

2006-12-27T04:53:19Z

Reynaldo: /* AMV Video File Format */

* Extension: amv (or [[mtv]])
* Samples: [http://www.mympxplayer.org/sample-videos-dc7.html] and [http://samples.mplayerhq.hu/amv/] 

==AMV video origin and history==
'''AMV''' is a video file format, used by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] and created to allow video playback capabilities on inexpensive equipment without increasing the cost of those players with the license royalties and more processor power needed for other more complex format/codec pairs. AMV files contain a [[RIFF]] packed stream of video ([[Talk:AMV|video codec?]]) and [[MP3]] encoded audio.

==AMV Video File Format==
AMV files contain a [[RIFF]] packed stream of video ([[Talk:AMV|video codec?]]) and [[MP3]] encoded audio.
 
When playing AMV formats, there is clearly some image de/compression taking place, as can be demonstrated by a simple calculation (see the [[MTV|MTV Video Format]] article). The image compression is, however, low by modern standards (around 4 pixels/byte, compared with over 10 pixels/byte in the [[MPEG-2]] DVD-Video standard). With a resolution of 128 x 96, and a frame rate of 12 fps, a 30 minute file will be around 80 MegaByte in size. 

==AMV and MTV encoding/transcoding information and utilities==
* [http://www.s1mp3.org/wiki/index.php/Video_encoding AMV encoding tips]
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)] 

==Software players that support AMV and MTV playback==
*Unknown
 

==Hardware players that support AMV and MTV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players]. 

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

 

[[Category:Video Codecs]]
[[Category:Undiscovered Video Codecs]]

AMV

2006-12-27T04:50:48Z

Reynaldo: /* AMV video origin and history */

* Extension: amv (or [[mtv]])
* Samples: [http://www.mympxplayer.org/sample-videos-dc7.html] and [http://samples.mplayerhq.hu/amv/] 

==AMV video origin and history==
'''AMV''' is a video file format, used by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] and created to allow video playback capabilities on inexpensive equipment without increasing the cost of those players with the license royalties and more processor power needed for other more complex format/codec pairs. AMV files contain a [[RIFF]] packed stream of video ([[Talk:AMV|video codec?]]) and [[MP3]] encoded audio.

==AMV Video File Format==
When playing AMV formats, there is clearly some image de/compression taking place, as can be demonstrated by a simple calculation (see the [[MTV|MTV Video Format]] article). The image compression is, however, low by modern standards (around 4 pixels/byte, compared with over 10 pixels/byte in the [[MPEG-2]] DVD-Video standard). With a resolution of 128 x 96, and a frame rate of 12 fps, a 30 minute file will be around 80 MegaByte in size. 

==AMV and MTV encoding/transcoding information and utilities==
* [http://www.s1mp3.org/wiki/index.php/Video_encoding AMV encoding tips]
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)] 

==Software players that support AMV and MTV playback==
*Unknown
 

==Hardware players that support AMV and MTV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players]. 

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

 

[[Category:Video Codecs]]
[[Category:Undiscovered Video Codecs]]

Talk:MTV

2006-10-12T23:21:57Z

Reynaldo:

is [[MTV]] a file-format or a video-codec?, I thought MTV was the video-codec and [[AMV]] was the file-format?!, both extentions (.mtv and .amv) can be found on [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player MP4/MTV-Player] download sites :/

Also see MTV discussion http://wiki.multimedia.cx/index.php?title=Talk:AMV

MTV is a multimedia container/file format, within an MTV file you found an [[MP3]] encoded audio track and [[RGB]] encoded image frame data.

MTV

2006-10-12T23:15:48Z

Reynaldo: /* Software players that support MTV and AMV playback */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
'''MTV''' is a video codec ([[Talk:MTV|or is it a video file format?]]), it was created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "'''MP4 Player'''" or "'''PMP'''", for '''P'''ersonal '''M'''edia '''P'''layer) are flash-based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to proprietary formats such as '''MTV''', [[AMV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files.

==MTV File Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing [[MP3]] audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats, as in fact very little "encoding" is actually done.

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necessarily aligned on block boundaries and each one of them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream. The first 12 bytes of each audio subblock is padding data and is always set to 0. Image data, on the other hand, is perfectly contained in each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the MP3 hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

{| class="wikitable" style="text-align:right"
![[Image:mtv_overview.png]]
|}

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frames/s, 22050 samples/s mono sound : 80 MB (approx) The audio is 22050 samples/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG-2 PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
The software available in April 2006 allows screen sizes of 94x64, 128x96 and 128x128 pixels, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*[[FFmpeg]]'s ffplay Supports MTV playback
*[[MPlayer]] supports MTV playback through FFmpeg's libavformat

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

AMV

2006-10-11T00:00:16Z

Reynaldo: /* AMV video origin and history */

* Extension: amv (or [[mtv]])
* Samples: [http://www.mympxplayer.org/sample-videos-dc7.html] 

==AMV video origin and history==
AMV is a video file format, used by [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] and created to allow video playback capabilities on inexpensive equipment without increasing the cost of those players with the license royalties (and more processor power). AMV is a video file format contain a [[MTV]] video stream and a [[MP3]] audio stream. The [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "'''MP4 Player'''" or "'''PMP'''", for '''P'''ersonal '''M'''edia '''P'''layer) that these video-files produced for are flash based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to the proprietary file formats such as [[AMV]], [[MTV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files. 

==AMV Video File Format==
When playing AMV formats, there is clearly some image de/compression taking place, as can be demonstrated by a simple calculation (see the [[MTV|MTV Video Format]] article). The image compression is, however, low by modern standards (around 4 pixels/byte, compared with over 10 pixels/byte in the [[MPEG-2]] DVD-Video standard). With a resolution of 128 x 96, and a frame rate of 12 fps, a 30 minute file will be around 80 MegaByte in size. 

==AMV and MTV encoding/transcoding information and utilities==
* [http://www.s1mp3.org/wiki/index.php/Video_encoding AMV encoding tips]
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)] 

==Software players that support AMV and MTV playback==
*Unknown
 

==Hardware players that support AMV and MTV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players]. 

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

 

[[Category:Video Codecs]]
[[Category:Undiscovered Video Codecs]]

MTV

2006-10-10T18:51:45Z

Reynaldo: /* MTV Video Format */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
The MTV Video format was created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "MP4 Player" or "PMP", for '''Personal''' '''M'''edia '''P'''layer) are flash based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to the proprietary file formats such as '''MTV''', [[AMV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files.

==MTV Video Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing MPEG1 Audio Layer 3 (AKA MP3) audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats (i.e. faster to encode on, say, desktop computer, and less hard on the batteries of the portable device), as in fact very little "encoding" is actually done

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necesarily aligned on blocks boundaries and each one off them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream, the first 12 bytes of each audio subblock is padding data and is allways set to 0. Image data, on the other side, is perfectly contained on each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the [[MP3]] hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

{| class="wikitable" style="text-align:right"
![[Image:mtv_overview.png]]
|}

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frame/s, 22050 sample/s mono sound : 80 MB (approx) The audio is 22050 sample/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.)

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG2-PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
Software available (to date April 2nd 2006) currently give screen sizes of 94x64, 128x96 and 128x128, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*Unknown

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-10-10T18:50:08Z

Reynaldo: /* File/Stream Overview */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
The MTV Video format was created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "MP4 Player" or "PMP", for '''Personal''' '''M'''edia '''P'''layer) are flash based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to the proprietary file formats such as '''MTV''', [[AMV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files.

==MTV Video Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing MPEG1 Audio Layer 3 (AKA MP3) audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats (i.e. faster to encode on, say, desktop computer, and less hard on the batteries of the portable device), as in fact very little "encoding" is actually done

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necesarily aligned on blocks boundaries and each one off them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream, the first 12 bytes of each audio subblock is padding data and is allways set to 0. Image data, on the other side, is perfectly contained on each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the [[MP3]] hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

{| class="wikitable" style="text-align:center"
![[Image:mtv_overview.png]]!
|}

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frame/s, 22050 sample/s mono sound : 80 MB (approx) The audio is 22050 sample/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.)

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG2-PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
Software available (to date April 2nd 2006) currently give screen sizes of 94x64, 128x96 and 128x128, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*Unknown

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-10-10T18:44:12Z

Reynaldo: /* MTV Video Format */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
The MTV Video format was created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "MP4 Player" or "PMP", for '''Personal''' '''M'''edia '''P'''layer) are flash based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to the proprietary file formats such as '''MTV''', [[AMV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files.

==MTV Video Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing MPEG1 Audio Layer 3 (AKA MP3) audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats (i.e. faster to encode on, say, desktop computer, and less hard on the batteries of the portable device), as in fact very little "encoding" is actually done

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necesarily aligned on blocks boundaries and each one off them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream, the first 12 bytes of each audio subblock is padding data and is allways set to 0. Image data, on the other side, is perfectly contained on each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the [[MP3]] hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

==File/Stream Overview==
[[Image:mtv_overview.png]]

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frame/s, 22050 sample/s mono sound : 80 MB (approx) The audio is 22050 sample/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.)

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG2-PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
Software available (to date April 2nd 2006) currently give screen sizes of 94x64, 128x96 and 128x128, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*Unknown

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

File:Mtv overview.png

2006-10-10T18:42:01Z

Reynaldo: Overview of and MTV file/stream structure

Overview of and MTV file/stream structure

MTV

2006-10-10T18:40:48Z

Reynaldo: /* MTV Video Format */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
The MTV Video format was created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "MP4 Player" or "PMP", for '''Personal''' '''M'''edia '''P'''layer) are flash based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to the proprietary file formats such as '''MTV''', [[AMV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files.

==MTV Video Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing MPEG1 Audio Layer 3 (AKA MP3) audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats (i.e. faster to encode on, say, desktop computer, and less hard on the batteries of the portable device), as in fact very little "encoding" is actually done

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necesarily aligned on blocks boundaries and each one off them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream, the first 12 bytes of each audio subblock is padding data and is allways set to 0. Image data, on the other side, is perfectly contained on each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the [[MP3]] hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.
[[Image:mtv_overview.png]]
===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frame/s, 22050 sample/s mono sound : 80 MB (approx) The audio is 22050 sample/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.)

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG2-PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
Software available (to date April 2nd 2006) currently give screen sizes of 94x64, 128x96 and 128x128, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*Unknown

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-10-10T16:59:34Z

Reynaldo: /* MTV Video Format */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
The MTV Video format was created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "MP4 Player" or "PMP", for '''Personal''' '''M'''edia '''P'''layer) are flash based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to the proprietary file formats such as '''MTV''', [[AMV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files.

==MTV Video Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing MPEG1 Audio Layer 3 (AKA MP3) audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats (i.e. faster to encode on, say, desktop computer, and less hard on the batteries of the portable device), as in fact very little "encoding" is actually done

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necesarily aligned on blocks boundaries and each one off them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream, the first 12 bytes of each audio subblock is padding data and is allways set to 0. Image data, on the other side, is perfectly contained on each image data block, each one representing an entire frame.

During decoding of the video stream, the audio frames are passed to the [[MP3]] hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frame/s, 22050 sample/s mono sound : 80 MB (approx) The audio is 22050 sample/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.)

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG2-PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
Software available (to date April 2nd 2006) currently give screen sizes of 94x64, 128x96 and 128x128, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*Unknown

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-10-10T16:53:48Z

Reynaldo: /* Encoding and transcoding/conversion software utilities */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
The MTV Video format was created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "MP4 Player" or "PMP", for '''Personal''' '''M'''edia '''P'''layer) are flash based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to the proprietary file formats such as '''MTV''', [[AMV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files.

==MTV Video Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing MP3 audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats (i.e. faster to encode on, say, desktop computer, and less hard on the batteries of the portable device), as in fact very little "encoding" is actually done

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necesarily aligned on blocks boundaries and each one off them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream, the first 12 bytes of each audio subblock is padding data and is allways set to 0. Image data, on the other side, is perfectly contained on each image data block, each one representing and entire frame. While the audio frames are encoded with MPEG1 Audio Layer 3 (a.k.a. [[MP3]]), the image information is stored in uncompressed raw format, according to the player's display hardware specification.

During decoding of the video stream, the audio frames are passed to the [[MP3]] hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frame/s, 22050 sample/s mono sound : 80 MB (approx) The audio is 22050 sample/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.)

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG2-PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
Software available (to date April 2nd 2006) currently give screen sizes of 94x64, 128x96 and 128x128, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*Unknown

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]

MTV

2006-10-10T16:49:57Z

Reynaldo: /* MTV Video Format */

* Extension: mtv (or [[amv]])
* Samples: http://samples.mplayerhq.hu/mtv/

==MTV video origin and history==
The MTV Video format was created to allow video playback capabilities on inexpensive [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''] without increasing the cost of those players with the license royalties (and more processor power). These [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese MP4/MTV Player'''] (sold as "MP4 Player" or "PMP", for '''Personal''' '''M'''edia '''P'''layer) are flash based [http://en.wikipedia.org/wiki/Digital_audio_player digital audio players], mostly manufactured in China, capable of viewing images, videos, and text files. Although commonly called MP4 players, they are unable to play true [[H.264| MP4 (MPEG-4 AVC H.264)]] formated videos and are limited to the proprietary file formats such as '''MTV''', [[AMV]], [[DMV]], [[MPV]], [[ATV]], and [http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player#ACT_Audio_Format ACT]. They are a kind of the [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Player]. This is beginning to change however, as more and more top-branded portable players are starting to support true [[H.264| MP4 (MPEG-4 AVC H.264)]] video files.

==MTV Video Format==
The format operates by displaying a series of raw uncompressed rgb565/555 image frames while playing MP3 audio but as the files are of low resolution and frame rate, sizes are comparable to [[MPEG-1]] or [[MPEG-2]]. (in a bytes-per-minute sense). Encoding and decoding are less processor-intensive than other contemporary formats (i.e. faster to encode on, say, desktop computer, and less hard on the batteries of the portable device), as in fact very little "encoding" is actually done

The MTV format consists of a 512 byte file header, followed by alternating audio and image blocks. Audio frame data is not necesarily aligned on blocks boundaries and each one off them has from 1 to n subblocks of 512 bytes each with 'n' remaining constant through the entire file/stream, the first 12 bytes of each audio subblock is padding data and is allways set to 0. Image data, on the other side, is perfectly contained on each image data block, each one representing and entire frame. While the audio frames are encoded with MPEG1 Audio Layer 3 (a.k.a. [[MP3]]), the image information is stored in uncompressed raw format, according to the player's display hardware specification.

During decoding of the video stream, the audio frames are passed to the [[MP3]] hardware decoder, while the memory pointer of the display hardware is simply adjusted to the next raw image within the video stream. While this concept does not require additional * hardware for the decoding process, it leads to huge memory requirements as no compression is applied to the image information. For this reason the storage capacity of an MP4 player is effectively much less than that of a player that decompresses files on the fly.

===MTV vs. [MPEG-2] (using typical values/approximations):===
'''Note!''' These MTV/[[AMV]] calculations are based on 30 minutes at 128 x 96 pixels, 12 frame/s, 22050 sample/s mono sound : 80 MB (approx) The audio is 22050 sample/s, mono, MP3(?) - a safe guess would be a maximum of 10 MB being audio, yielding 70 MB for video, or approximately 40,000 bytes per second.)

{| class="wikitable" style="text-align:right"
! file !! Approx. data rate !! Resolution (pixels) !! Frame rate !! Pixels per second !! Pixels per byte
|-
! AMV
| 40,000 B/s
| 128 x 96 = 12,288
| 12 fps
| 147,456
| ~3.5
|-
! DVD (MPEG2-PAL)
| > 1,000,000 B/s
| 704 x 576 = ~400,000
| 25 fps
| ~10,000,000
| ~10
|}

==Encoding and transcoding/conversion software utilities==
Software available (to date April 2nd 2006) currently give screen sizes of 94x64, 128x96 and 128x128, typically set to frame rates of 8, 12 and 16 frames per second (described as "low","medium" and "high"), which fits reasonably well on 1.2 to 1.5+ inch screens. By editing configuration files the range of frame rates handled by the encoder can be expanded to 8-24 (in 1fps increments), though using alternate framerates may cause problems if the player is not designed for those alternates. 
* [http://www.mympxplayer.org/tools-dc10.html www.mympxplayer.org - MP4 resource site and support forum, with MTV conversion/transcoding tools and utilies, (plus sample downloads)]
* [http://www.s1mp3.org/wiki/index.php/Video_encoding MTV/AMV encoding tips]

==Software players that support MTV and AMV playback==
*Unknown

==Hardware players that support MTV and AMV playback==
[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player '''Chinese-made portable MP3 players'''], also known as [http://en.wikipedia.org/wiki/S1_MP3_Player S1 MP3 Players].

==External Links==
*[http://en.wikipedia.org/wiki/Chinese_MP4/MTV_Player "Chinese-made portable MP3 player" article on wikipedia.org]
*[http://en.wikipedia.org/wiki/S1_MP3_Player "S1 MP3 Player" article on wikipedia.org]
* [http://www.mympxplayer.org www.mympxplayer.org - MP4 resource site and support forum, MTV conversion/transcoding tools and utilies, plus sample downloads]
*[http://www.moviecodec.com/topics/7595p1.html MTV Video topic-thread on moviecodec.com forum]
* [http://mp4-player-search-swicki.eurekster.com/ MP4 Player Search - Community powered and driven]
* [http://www.mp4nation.com/software/index.html MP4 Nation Knowledge Base: Support and tips on MP4 Players]
* [http://www.imup2date.co.uk/MP4/ An introduction to MP4 players, what they do, what you can do to them and a review]
* [http://www.s1mp3.org/en/docs_deadrec.php Recovering dead players and other software]
* [http://forum.s1mp3.org/ MP4 Forums on S1MP3.org]
* [http://www.moviecodec.com/topics/7595p3.html MTV Video Forum]
* [http://www.youtube.com/watch?v=us507LedkyY (A very negative) video-review of one of these MP4-Player on Youtube]

[[Category:Container Formats]]