Libav Summer Of Code 2012

2012-03-09T19:26:23Z

Ronald S. Bultje: revert

Libav Summer Of Code 2012

2012-03-09T19:18:47Z

Ronald S. Bultje: remove deadlines edit - this is not a WIP page

FATE failures

2012-03-01T19:07:24Z

Ronald S. Bultje: /* H.264 */

Although FATE can appear green, in fact many of the samples in FATE are not bit-exact.

The following samples are not bit-exact.

=== H.264 ===

tandberg 4/5 have large codec delays because of misordered frames, and the delay jumps randomly within the file. We don't preroll well enough to know the correct delay in advance and so at each point where we return a frame too far ahead in the future, we drop the preceeding frames once we get around to decoding them because we've already passed that point in units returned to the application. The correct solution for these would be to increase delay dynamically whenever we encounter a gap until either we're at max-delay, or until we've resolved the gap. almost certainly, max-delay should be settable in user applications so we can disable it for live/low-latency purposes. Q: should we return old frames also? The user may want to reorder himself (although this doesn't make much sense). Fate currently uses -strict 1 as a workaround for these samples, which simply forces codec-delay to 16. This is not the correct solution.
MAIN/MR4_TANDBERG_C.264 ... JF ( yuv420p @ 176x144 / 25 fps) not equal
MAIN/MR5_TANDBERG_C.264 ... JF ( yuv420p @ 176x144 / 25 fps) not equal

=== Other samples from the H264 conformance suite that don't play back correctly ===

FMO:
MAIN/FM1_FT_E.264 ... JF ( yuv420p @ 176x144 / 25 fps) not equal
MAIN/FM2_SVA_C.264 ... JF ( yuv420p @ 176x144 / 25 fps) not equal
MAIN/FM1_BT_B.h264 ... JF ( yuv420p @ 176x144 / 25 fps) not equal

For this one, we output only 12 of a few hundred-or-so frames, unanalyzed beyond that:
MAIN/sp1_bt_a.h264 ... JF ( yuv420p @ 176x144 / 25 fps) not equal

Looks like garbage, unanalyzed beyond that:
MAIN/H26L/BitstreamExchange/sp2_bt_b.h264 ... JF ( yuv420p @ 176x144 / 25 fps) not equal

Cropping:
MAIN/CVFC1_Sony_C.jsv ... JF ( yuv420p @ 338x274 / 25 fps) not equal

Looks like CAVLC-444 isn't completely implemented:
PP/PPCV444I-7.264 ... JF ( yuv420p @ 48x80 / 25 fps) not equal
PP/PPCV444I4_Mitsubishi_A.264 ... JF ( yuv420p @ 48x48 / 25 fps) not equal
PP/PPCV444I5_Mitsubishi_A.264 ... JF ( 50 fps @ 25 tbr / 25 fps) not equal
PP/PPCV444I6_Mitsubishi_A.264 ... JF ( yuv420p @ 48x48 / 25 fps) not equal
PP/Professional_profiles/PPCV444I1_Thomson_A.bits ... JF ( 50 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPCV444I2_Thomson_A.bits ... JF ( 50 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPCV444I3_Thomson_A.bits ... JF ( 50 fps @ 25 tbr / 25 fps) not equal

Missing 14-bits support:
PP/PPH444I4_Mitsubishi_A.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/PPH444I5_Mitsubishi_A.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/PPH444I6_Mitsubishi_A.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/PPH444P6_Mitsubishi_A.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/PPH444P7_Mitsubishi_A.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/PPH444P8_Mitsubishi_A.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/PPH444P9_Mitsubishi_A.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPH444I1_Thomson_A.bits ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPH444I2_Thomson_A.bits ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPH444I3_Thomson_A.bits ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPH444P1_Thomson_A.bits ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPH444P2_Thomson_A.bits ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPH444P3_Thomson_A.bits ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPH444P4_Thomson_A.bits ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/Professional_profiles/PPH444P5_Thomson_A.bits ... JF ( 25 fps @ 25 tbr / 25 fps) not equal

FMO + 14-bits:
PP/PPH444I-7.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal
PP/PPH444P-10.264 ... JF ( 25 fps @ 25 tbr / 25 fps) not equal

[[Category:FATE]]

Libav Summer Of Code 2012

2012-02-17T15:34:45Z

Ronald S. Bultje: Remove references to ffmpeg except where historically relevant

Libav Summer Of Code 2012

2012-02-17T15:31:15Z

Ronald S. Bultje: Michael will not be a mentor for the Libav summer of code

FFmpeg / Libav Summer Of Code 2012

2012-02-17T15:30:41Z

2012-01-27T10:09:33Z

Ronald S. Bultje: /* Contacting developers/mentors */

== How it works ==

Google's Summer of Code program is simple: you (the student) work on a task, full-time, during the whole summer, and you get assistance (advice, mentoring) from a seasoned FFmpeg/Libav developer who knows his way around the project and has considerable standing in the community. By doing so, you'll learn to operate in an opensource project, you'll get relevant coding experience, and you'll have a chance at earning money while doing fun stuff during the summer. So, you need a task, a mentor, do a qualification task (see below) so we can quickly assess how good a candidate we feel you'll be for the program, and then you can apply.

=== Selecting a tasks ===
Below, you'll find two lists of tasks:
* Tasks with a mentor
* Tasks without a mentor
If you choose a task with a mentor, talk to that mentor (see below) and select a suitable qualification task. Once completed, you're eligible for participating in our Summer of Code program. If you choose a task without a mentor, your first job is to find a mentor (see below). Then, once you've found a mentor, continue as before. If you don't like any of the tasks, you're free to define your own task and find a mentor as mentioned before (see below for caveats).

=== Contacting developers/mentors ===
Once you've found a task (with or without mentor), start talking to the developers of the FFmpeg and Libav projects. We can often be found on IRC, and you can talk to us on mailinglists also. Hop on irc.freenode.net channels #ffmpeg or #libav, or talk to us on libav-devel@libav.org or ffmpeg-devel@ffmpeg.org. (At this point, you're probably wondering why there are 2 IRC channels and 2 mailinglists. Ask your mentor, it'll make for a good first conversation topic.) Here, you'll be able to ask around for mentors for projects without a mentor if you need to. If you're trying to define your own task, explain (with reasonable amount of detail) what you intend to achieve and why you think your task should be in our Summer of Code program. Once you've found a mentor, you're good to start your qualification task.

Note that the self-selected mentor needs to have considerable standing in the community to be eligible for mentoring. Likewise, if you choose to define your own Summer of Code task, some community members of considerable standing need to vouch for your task.

=== Your qualification task ===
The goal of a qualification task is to see if the mentor and student feel that together, they will be able to finish the task of their choice. More specifically, the mentor will want to test whether he thinks that the student has the skills and work ethics to complete a large coding task in a limited amount of time. The student will want to make sure that the mentor provides (useful) assistance when necessary. Therefore, students should select a mentor and a Summer of Code task before starting their work on a qualification task. The qualification task is often (but not necessarily) related to the selected task. For example, if your task will be to reverse engineer a new video codec, the qualification task may be to write a partial bitstream parser for that codec. If your task is to write a muxer for a container format, the qualification task may be to write the code to write the stream header.

=== Applying ===
While you're working on your qualification task, apply at http://www.google-melange.com/. The degree (and detail) with which you've finished your qualification task will determine how likely your project is to be selected. Generally, students that completely finish their qualification task always get selected as Summer of Code students, but that may vary depending on the number of spots we get assigned by Google.

=== Videolan qualification tasks ===
A completed FFmpeg/Libav qualifications task is also accepted as a qualification task for the VLC organization (does NOT include x264).

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

=== HEVC/H265 decoder ===

* HEVC is the next-generation video standard from the MPEG standards committee. Your job is to write a decoder that can playback HEVC files.
* It does not need to be SIMD-optimized, but preferably has relevant functions separated in DSP contexts so they're easy to optimize later on.

''Mentor: [[User:Ronald_S._Bultje|Ronald S. Bultje]]''

2011-03-09T17:39:04Z

Ronald S. Bultje: /* VC1 decoder missing features */

== Qualification tasks ==

For us to consider your application for SoC we require a completed qualification task. Many Summer-of-Code projects (in the list below) have specific qualification tasks. These tasks are meant to make you familiar with the code that you will be working with, are at approximately the same difficulty level as the actual Summer-of-Code project itself (just a lot smaller), and often already provide you with a jumpstart into your Summer-of-Code project. We suggest the following order of events:
* First, select a Summer-of-Code project (either from the list below, but in some cases you may also come up with your own)
* Second, discuss this project with the person that will mentor it. If a mentor is listed, talk to him on IRC, via email or so. If no mentor is listed, find one by emailing the FFmpeg-soc mailinglist.
* With your mentor, discuss the most appropriate qualification task for your Summer-of-Code project.
If no specific qualification task is listed for your project of interest, you can discuss with your mentor to choose a task from the [[Small FFmpeg Tasks|Small Tasks list]] or the [[Interesting Patches|Interesting Patches list]] instead. If your prospective mentor agrees, please send an email to the FFmpeg-soc mailing list to inform that you are working on it (to avoid duplicated work). You can discuss progress on your qualification task and initial review of your finished qualification task on the FFmpeg-soc mailinglist (sometimes the patch will have to go through final review on the main FFmpeg development mailinglist before it can be applied also). The qualification task is considered completed when your patch is accepted to our main SVN tree.

Before posting to the FFmpeg-soc mailinglist, make sure you read and understand [http://www.ffmpeg.org/contact.html our netiquette guidelines], especially avoid top-posting and thread-hijacking (note that if you don't understand one of those terms, make sure to have understood them before writing your first post). Before you send us your patch, read our [http://www.ffmpeg.org/general.html#SEC23 development guidelines] and make sure your patch fulfills all the requirements stated there. You should also familiar with the programs diff, patch and Subversion. You have to learn these basics on your own before you start, we will not teach them to you during the application process.

A completed FFmpeg qualifications task is also accepted as a qualification task for the VLC organization (does NOT include x264).

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

=== [[Advanced_Audio_Coding#BSAC_AAC|BSAC AAC]] Decoder ===

* Separate [[AAC]] Huffman decoding and dequantization from the rest of AAC decoder.
* Write a BSAC AAC decoder.
* Reuse as much of the existing AAC decoder and libavcodec as possible.

''Mentor: [[User:AConverse|Alex Converse]]

=== [[VC-1]] decoder missing features ===
* Add support for interlaced streams as used in Bluray recordings to the VC-1 decoder.
* Add support for chroma/luma scaling, used in [https://roundup.ffmpeg.org/issue1477 RTP/VC1].
* Add support for slice decoding, used in [https://roundup.ffmpeg.org/issue1477 RTP/VC1].
* Add optimizations for x86-32/64 (or ARM), so that HD streams play back faster.
* This includes fixing some reference streams

''Mentor: [[User:Kostya|Kostya Shishkov]], [[User:Ronald S. Bultje|Ronald S. Bultje]] and (maybe) Christophe Gisquet''

=== [[WTV|Windows Television (WTV)]] muxer ===

* Qualification task: develop a prototype WTV muxer that can produce files then able to be demuxed by FFmpeg.
* The objective of this project is produce files that are compatible with Microsoft Windows Media Center. To achieve this, one must determine which of the many undocumented data types are expected by Microsoft Stream Buffer Engine, discover their format, and implement these in the muxer.
* The muxer must support metadata and indexing.
* Clearly defined task; reverse engineering skills required.
''Mentor: [[User:Suxen_drol|Peter Ross]]

== 1st tier proposals of last year ==
These are the same as above-mentioned 1st tier proposals, but we're not sure yet if we'll repeat them. Once mentors are OK, please move them up.

=== NEW Seeking API ===
*primary goal: implement a new seeking API in libavformat
** implement av_seek_file in libavformat
** implement compatible new seek_file for all AVInputFormat porting existing seek function if possible.
** implement av_build_index function which will build an AVIndex for the file
** implement av_export_index function which will save AVIndex in a file which can be loaded later.

''Mentor: Baptiste Coudurier''

=== AACS implementation ===
* this task probably is to get libbluray integrated with vlc/mplayer/ffmpeg and working with as many discs as possible.
* Add the ability to encode and decode using Advanced Access Content System to FFmpeg.
* Specifications: http://www.aacsla.com/specifications/
* existing implementation e.g. DumpHD: http://forum.doom9.org/showthread.php?t=123111
* Most parts (BD-J, MKB, title key generation) probably do not belong into FFmpeg, this should be discussed with us before submitting an application
** possible solution: only implement "lowest" level (decode given the correct title key) but implement CSS en- and decryption as secondary goal

''Mentor: Reimar Döffinger''

=== [[Libavfilter]] video work ===
Libavfilter is the FFmpeg filtering library that started as a 2007 SoC [[FFmpeg Summer Of Code#Video Filter API (AKA libavfilter)|project]]. It replaced the now removed vhook subsystem. Most of it is already part of the FFmpeg main source tree, but there a few bits remaining. This project would consist in a combination of the following tasks:

* Get the remaining bits of the SoC tree committed (this includes: the rotate, split, and fps filters)
* Port all the missing filters from MPlayer (do not forget asking the authors if it is ok to release them under the LGPL)
* Framework: implement dynamic-reconfiguration of the filterchain, for supporting dynamic size/format changes
* Port filters from other frameworks (yuvjpeg, effectv, frei0r, virtualdub, vlc, etc...)
* Write wrappers for more image processing libraries and filtering frameworks (libgimp, libgraphicsmagic, weed), extend the libopencv wrapper for supporting more filters (this may need implemented float image support in libswscale)
* Write more filters (possibly starting from already posted filters which for a reason or another were never committed, e.g. concatenate, fish, 2xsai, select, lut, eval, posterize, elbg/posterize etc.)
* Implement a compose filter (suggestion for a better name?), for creating a mosaic of the input video streams
* Write a movie sink (e.g. it could be useful for implementing a display functionality, e.g. when the video is dumped to an output device)
* Write a frequency domain filter using the FFT implementation in libavcodec
* Write a Matlab/Octave/SAGE scripting wrapper (assuming it can be done)
* More ideas?

''Mentor: To be determined''

=== [[Libavfilter]] audio work ===
At the moment, FFmpeg filtering library has incomplete support for handling audio. This task would consist of a combination of the following tasks:

* Fix the remaining outstanding issues and complete the audio framework integration (check the saste's audio-filters FFmpeg branch on gitorious)
* Make the resampling filter works for several combinations of sample format and channels
* Write a visualization filter as proof-of-concept of a filter that works with both video and audio
* Extend/improve libav* audio resampling/rematrixing/requantization capabilities (this may need to re-design the audio API, maybe it deserves a task on its own)
* Write/port basic audio filters (check libaf in MPlayer/libmpcodecs)
* Write wrapper for audio frameworks (sox, ladspa, ...)

''Mentor: To be determined''

=== Rewrite the audio format conversion code ===

* right now, we're using audioresample to resample audio (samplerate / channels) and audioconvert to resample audio format (int, float, 16-bit, 32-bit). We'd like a new, swscale-style implementation that combines these two in a single codebase
* design should allow for SIMD optimization of popular conversions (float-int16, int16-float)
* fix bugs in current design (clipping, overflows when going from float to int, questionable rounding)

''Mentor: to be decided

=== DTS Encoder ===
* Specification: http://wiki.multimedia.cx/index.php?title=Mirror
* Sample files: http://samples.mplayerhq.hu/A-codecs/DTS/
* Qualification: Extend the encoder in the SoC tree (port the float transform from the decoder, fix the LFE channel generation).
* Primary goal: Encoder that can produce multi sample rate, multi channel files and multi bit-rate. Wav and raw muxing support. SVN merge.
* Secondary goal: Techniques from specification implemented, optimal codebook usage, vector quantization, simple psycho acoustics.
* Third goal: Advanced psycho acoustics.

''Mentor: Benjamin Larsson''

=== h264 decoder optimizations ===
* Quite simply, make our decoder faster
* Qualification task: make our decoder 1% faster

''Mentor: Michael Niedermayer''

=== Add support for Bayer RGB colour format ===
Since it is not even clear if this should be implemented in libswscale or libavcodec, this should be discussed on ffmpeg-devel or ffmpeg-soc before submitting.
There was a related discussion on mplayer-devel once and at least two related FFmpeg issues:
* http://thread.gmane.org/gmane.comp.video.mplayer.devel/48091
* http://roundup.ffmpeg.org/issue1816
* http://roundup.ffmpeg.org/issue1837
* Contact Peter Ross for his latest working patch (Jan-2011)

''Mentor: Michael Niedermayer''

== 2nd Tier Project Proposals ==
All that separates these proposals from their 1st tier brethren is a lack of mentor.

=== Finish SoC projects from previous years ===
Some projects are lingering in the dark unfinished. They should be picked up and made ready for inclusion. These projects are potentially less involved than starting from scratch, but also more useful for FFmpeg since the probability that the projects get finished should be higher. If some of them are deemed too easy, they could be combined.

Unfinished projects from previous years are:

2007:
* [[FFmpeg Summer Of Code#JPEG 2000 Encoder and Decoder|JPEG 2000 decoder]]
* [[FFmpeg Summer Of Code#JPEG 2000 Encoder and Decoder|JPEG 2000 encoder]]
* [[FFmpeg Summer Of Code#Dirac Encoder and Decoder|Dirac decoder]]
* [[FFmpeg Summer Of Code#Dirac Encoder and Decoder|Dirac encoder]]
* [[FFmpeg Summer Of Code#TS Muxer|TS muxer]]

2008:
* [[FFmpeg Summer Of Code#Generic frame-level multithreading support|Generic frame-level multithreading support]]

2009:
* [[FFmpeg_Summer_Of_Code#Playlist.2FConcatenation_Support_for_FFmpeg|Playlist and concatenation support]]
* [[FFmpeg_Summer_Of_Code#Implement_the_New_Seeking_API_in_Libavformat|New seeking API]]
* [[FFmpeg_Summer_Of_Code#Implementation_of_AVFilter_infrastructure_and_various_audio_filters|AVFilter audio infrastructure]]

For the current status of all SoC projects up to date, see [[FFmpeg Summer Of Code]].

=== Implement a Windows Video Presentation 2 decoder ===
* Fourcc: [[WVP2]]
* Samples: [http://samples.mplayerhq.hu/V-codecs/WVP2/ http://samples.mplayerhq.hu/V-codecs/WVP2/]
* Suggested qualification task: [[Reverse_Engineering|Reverse engineer]] the frame header parsing or the actual frame data parsing

=== WMA lossless ===
* Implement a decoder for WMA lossless (0x0163)
* Reuse as much libavcodec code as possible
* Samples: http://samples.mplayerhq.hu/A-codecs/WMA9/wma_0x163.wma http://samples.mplayerhq.hu/A-codecs/lossless/luckynight.wma

=== RALF Realaudio Lossless ===
* RE and implement a decoder for this format
* Reuse as much libavcodec code as possible

=== libvo ===
* Port MPlayer's libvo to ffplay
* Note that this does not just mean to produce a working hack so that ffplay can use xv, but a clean and acceptable wrapper for (most of) libvo.
* An alternative might be to only port the OpenGL part of libvo into a new glplay. This should be discussed on ffmpeg-devel before submission.

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

=== CELT Decoder ===
* Specification: http://celt-codec.org/docs
Also see [[CELT]].

=== 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]].

=== VP6 Encoder ===
* Specification: [[On2 VP6]]
* Samples: http://samples.mplayerhq.hu/V-codecs/VP6/

=== 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 subtitle support ===

* Add text-to-bitmap conversion functions
* One with hard-coded bitmaps for characters
* One that utilizes freetype
* Function used will be chosen upon compilation

Adjust existing subtitle support to new ABI
* ABI change: http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2009-January/058521.html

=== Improve Ratecontrol ===
*Primary goal 1: Fast heuristic VBV compliant per macroblock ratecontrol which has a better PSNR/bitrate and better subjective quality/bitrate than the current code.
*Primary goal 2: VBV compliant, rate distortion optimal per macroblock ratecontrol using the viterbi algorithm.
*Secondary goal 1: Fast heuristic scene change detection which detects scene changes more accurately, has better PSNR/bitrate and subjective quality/bitrate than the current heuristic.
*Secondary goal 2: Rate distortion optimal (for the current picture) scene change detection.
*Secondary goal 3: B frames decision which is faster and or has a higher PSNR/bitrate and subjective quality/bitrate than the current code.

=== SILK decoder and/or encoder ===
* A specification was published: http://tools.ietf.org/html/draft-vos-silk-01

=== DTS-HD Master Audio decoder ===
* You should know exactly what you do if you submit an application.

=== ATRAC3plus ===
* Implement a decoder for [[ATRAC3plus]].

=== Dolby E ===
* Implement a decoder for [[Dolby E]].

=== MPEG-4 SLS ===
* FFmpeg has currently no support for [[MPEG-4 SLS]]

=== DirectShow capture ===
* Implement an indev for DirectShow capture on Windows (and support A/V synchronisation).
* Qualification: Get [http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/106245 GDI] and [http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/105810 waveform] capture integrated into FFmpeg SVN with A/V synchronisation. Both patches are almost finished.

[[Category:FFmpeg]]