MultimediaWiki - Recent changes [en]

FFmpeg Summer of Code 2013

Stefanosa — Wed, 06 Mar 2013 23:43:58 GMT

reduce nesting level by one

Revision as of 23:43, 6 March 2013		Current revision
Line 10:		Line 10:
	When adding an idea follow this template for consistency:		When adding an idea follow this template for consistency:

-	== Example Title ==	+	<pre>
		+	== Task Title ==

	'''Description:''' A few sentences or a short paragraph describing the task.		'''Description:''' A few sentences or a short paragraph describing the task.
Line 19:		Line 20:

	'''Mentor:''' List mentor and backup mentor if there is one and contact info such as IRC name or email address.		'''Mentor:''' List mentor and backup mentor if there is one and contact info such as IRC name or email address.
		+	</pre>

-	= GSoC task proposal ideas =	+	= Mentored tasks =

-	== Mentored tasks ==	+	== H264 MVC ==
-		+
-	=== H264 MVC ===	+

	'''Description:''' MVC samples exist, the codec is used on Bluray media, FFmpeg is missing a decoder. Since this task also consists of some changes in the current architecture, it is especially important that this task is discussed on the ffmpeg-devel mailing list.		'''Description:''' MVC samples exist, the codec is used on Bluray media, FFmpeg is missing a decoder. Since this task also consists of some changes in the current architecture, it is especially important that this task is discussed on the ffmpeg-devel mailing list.
Line 31:		Line 31:
	'''Mentor:''' Michael Niedermayer		'''Mentor:''' Michael Niedermayer

-	=== Animated Portable Network Graphics (APNG) ===	+	== Animated Portable Network Graphics (APNG) ==

	'''Description:''' FFmpeg currently does not support Animated PNGs.		'''Description:''' FFmpeg currently does not support Animated PNGs.
Line 69:		Line 69:
	'''Mentor: [[User:Pbm\|Paul B Mahol]]'''		'''Mentor: [[User:Pbm\|Paul B Mahol]]'''

-	=== Misc Libavfilter extension ===	+	== Misc Libavfilter extension ==

	<div class="floatright">[[Image:Lavfi-gsoc-filter-vintage-illustration.jpg]]</div>		<div class="floatright">[[Image:Lavfi-gsoc-filter-vintage-illustration.jpg]]</div>
Line 91:		Line 91:
	'''Qualification task:''' write or port one or more filter		'''Qualification task:''' write or port one or more filter

-	'''Mentor:''' Stefano Sabatini (''saste'' on IRC). Backup: Clément Bœsch (''ubitux'' on IRC).	+	'''Mentor:''' [[User:Stefanosa\|Stefano Sabatini]]. Backup mentor: Clément Bœsch (''ubitux'' on IRC).

	<br clear="all">		<br clear="all">
	<div class="floatright">[[Image:Three-two pulldown diagram (telecine).png]]</div>		<div class="floatright">[[Image:Three-two pulldown diagram (telecine).png]]</div>

-	=== Inverse telecine filter ===	+	== Inverse telecine filter ==

	'''Description:''' Libavfilter has all kind of filters but is really lacking an IVTC one. It's a must-have we have been delaying for too long.		'''Description:''' Libavfilter has all kind of filters but is really lacking an IVTC one. It's a must-have we have been delaying for too long.
Line 112:		Line 112:
	<br clear="all">		<br clear="all">

-	=== Subtitles ===	+	== 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 carry an historical burden not easy to deal with, and introduces various issues very specific to its sparse form.		'''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 carry an historical burden not easy to deal with, and introduces various issues very specific to its sparse form.
Line 129:		Line 129:
	'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).		'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).

-	=== glplay ===	+	== glplay ==

	<div class="floatright">[[Image:Opengl_logo.jpg]]</div>		<div class="floatright">[[Image:Opengl_logo.jpg]]</div>
Line 139:		Line 139:
	<br clear="all">		<br clear="all">

-	=== Unmentored tasks ===	+	= Unmentored tasks =

-	=== AAC ===	+	== AAC ==

	'''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.		'''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.
Line 151:		Line 151:
	See also the FFmpeg bug tracker for AAC issues, fixing one of them or rebasing the existing incomplete BSAC decoder for current git head fixing one or more existing bugs are possible qualification tasks.		See also the FFmpeg bug tracker for AAC issues, fixing one of them or rebasing the existing incomplete BSAC decoder for current git head fixing one or more existing bugs are possible qualification tasks.

-	=== DTS / DCA ===	+	== DTS / DCA ==

	'''Description:''' FFmpeg contains a DTS decoder and an experimental DTS encoder. Both are missing some features.		'''Description:''' FFmpeg contains a DTS decoder and an experimental DTS encoder. Both are missing some features.
Line 162:		Line 162:
	* DTS encoder improvements		* DTS encoder improvements

-	=== MPEG-4 ALS encoder ===	+	== MPEG-4 ALS encoder ==

	'''Description:''' An ALS decoder was implemented several years ago, an encoder is still missing.		'''Description:''' An ALS decoder was implemented several years ago, an encoder is still missing.

-	=== TrueHD encoder ===	+	== 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.		'''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 ===	+	== Opus decoder ==

	'''Description:''' Opus decoding is currently supported through the external libopus library		'''Description:''' Opus decoding is currently supported through the external libopus library
Line 176:		Line 176:
	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.		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.

-	=== HEVC / H265 ===	+	== HEVC / H265 ==

	'''Description:''' The specification was finished, FFmpeg needs a decoder for this new format.		'''Description:''' The specification was finished, FFmpeg needs a decoder for this new format.
Line 183:		Line 183:
	As a qualification task you need to implement parsing headers and maybe a bit beyond that to demonstrate that you are qualified and understand the HEVC specification. This project requires a solid understanding of video coding and C, it's not something for the average SOC student.		As a qualification task you need to implement parsing headers and maybe a bit beyond that to demonstrate that you are qualified and understand the HEVC specification. This project requires a solid understanding of video coding and C, it's not something for the average SOC student.

-	=== VC-1 interlaced ===	+	== 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.		'''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.
Line 190:		Line 190:
	As a qualification task, you should try to find a bug in the current decoder implementation and fix it.		As a qualification task, you should try to find a bug in the current decoder implementation and fix it.

-	=== JPEG 2000 ===	+	== JPEG 2000 ==

	<div class="floatleft">[[Image:Jpeg2000.jpg]]</div>		<div class="floatleft">[[Image:Jpeg2000.jpg]]</div>
Line 199:		Line 199:
	<br clear="all">		<br clear="all">

-	=== VP7 ===	+	== VP7 ==

	'''Description:''' Not many VP7 samples are in the wild, but no open-source decoder exists although a specification exists. Write a decoder that reuses as much as possible of existing FFmpeg code, it is likely that functions of the existing decoders for On2-based formats will be useful.		'''Description:''' Not many VP7 samples are in the wild, but no open-source decoder exists although a specification exists. Write a decoder that reuses as much as possible of existing FFmpeg code, it is likely that functions of the existing decoders for On2-based formats will be useful.

	[[Category:FFmpeg]]		[[Category:FFmpeg]]

User:Stefanosa

Stefanosa — Wed, 06 Mar 2013 23:29:28 GMT

add a bit of information to my own page

Revision as of 23:29, 6 March 2013		Current revision
Line 1:		Line 1:
-	Stefano Sabatini	+	Stefano Sabatini, FFmpeg developer in the area of ffprobe, libavfilter, documentation and misc stuff.
		+
		+	He is saste on IRC (freenode).

FFmpeg Summer of Code 2013

Stefanosa — Wed, 06 Mar 2013 23:25:46 GMT

move mentored task to the top of the page

Revision as of 23:25, 6 March 2013		Current revision
Line 22:		Line 22:
	= GSoC task proposal ideas =		= GSoC task proposal ideas =

-	== Audio codecs ==	+	== Mentored tasks ==
-		+
-	<center>[[Image:Audio_Spectrum.png]]</center>	+
-		+
-	=== AAC ===	+
-		+
-	'''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 LD decoder	+
-	* 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	+
-	* AAC multi-channel encoding	+
-	See also the FFmpeg bug tracker for AAC issues, fixing one of them or rebasing the existing incomplete BSAC decoder for current git head fixing one or more existing bugs are possible qualification tasks.	+
-		+
-	=== DTS / DCA ===	+
-		+
-	'''Description:''' FFmpeg contains a DTS decoder and an experimental DTS encoder. Both are missing some features.	+
-	* DTS-HD decoder improvements: A possible qualification task is to implement ticket #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	+
-	* DTS encoder improvements	+
-		+
-	=== MPEG-4 ALS encoder ===	+
-		+
-	'''Description:''' An ALS decoder was implemented several years ago, an encoder is still missing.	+
-		+
-	=== 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 ===	+
-		+
-	'''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.	+
-		+
-	== Video codecs ==	+
-		+
-	<center>[[Image:BBB-Scenes.jpg]]</center>	+
-		+
-	=== HEVC / H265 ===	+
-		+
-	'''Description:''' The specification was finished, FFmpeg needs a decoder for this new format.	+
-	* Write a basic decoder supporting I, P, and, only if time permits, B slices.	+
-	* It does not need to be ASM/SIMD optimized but its high level structure must permit such optimizations to be easily added later.	+
-	As a qualification task you need to implement parsing headers and maybe a bit beyond that to demonstrate that you are qualified and understand the HEVC specification. This project requires a solid understanding of video coding and C, it's not something for the average SOC student.	+

	=== H264 MVC ===		=== H264 MVC ===
Line 78:		Line 30:

	'''Mentor:''' Michael Niedermayer		'''Mentor:''' Michael Niedermayer
-
-	=== 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.
-	* Implement missing interlace features
-	* Make more reference samples bit-exact
-	As a qualification task, you should try to find a bug in the current decoder implementation and fix it.

	=== Animated Portable Network Graphics (APNG) ===		=== Animated Portable Network Graphics (APNG) ===
Line 123:		Line 68:

	'''Mentor: [[User:Pbm\|Paul B Mahol]]'''		'''Mentor: [[User:Pbm\|Paul B Mahol]]'''
-
-	=== JPEG 2000 ===
-
-	<div class="floatleft">[[Image:Jpeg2000.jpg]]</div>
-
-	'''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.
-	Work on an issue (for example from the bug tracker) as a qualification task to show that you are capable of improving the codec implementation.
-
-	<br clear="all">
-
-	=== VP7 ===
-
-	'''Description:''' Not many VP7 samples are in the wild, but no open-source decoder exists although a specification exists. Write a decoder that reuses as much as possible of existing FFmpeg code, it is likely that functions of the existing decoders for On2-based formats will be useful.
-
-	== Other ==
-
-	=== glplay ===
-
-	<div class="floatright">[[Image:Opengl_logo.jpg]]</div>
-
-	'''Description:''' The SDL library that is used by FFplay has some deficiencies, adding OpenGL output to FFplay should allow for better performance (and less bugs at least for some hardware / driver combinations). This could be a new application (glplay), but it is probably simpler to extend ffplay to use OpenGL. You can use code from MPlayer's OpenGL vo module which may be relicensed under the LGPL.
-
-	'''Mentor:''' TBD Backup: Reimar Döffinger
-
-	<br clear="all">

	=== Misc Libavfilter extension ===		=== Misc Libavfilter extension ===
Line 208:		Line 128:

	'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).		'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).
		+
		+	=== glplay ===
		+
		+	<div class="floatright">[[Image:Opengl_logo.jpg]]</div>
		+
		+	'''Description:''' The SDL library that is used by FFplay has some deficiencies, adding OpenGL output to FFplay should allow for better performance (and less bugs at least for some hardware / driver combinations). This could be a new application (glplay), but it is probably simpler to extend ffplay to use OpenGL. You can use code from MPlayer's OpenGL vo module which may be relicensed under the LGPL.
		+
		+	'''Mentor:''' TBD Backup: Reimar Döffinger
		+
		+	<br clear="all">
		+
		+	=== Unmentored tasks ===
		+
		+	=== AAC ===
		+
		+	'''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 LD decoder
		+	* 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
		+	* AAC multi-channel encoding
		+	See also the FFmpeg bug tracker for AAC issues, fixing one of them or rebasing the existing incomplete BSAC decoder for current git head fixing one or more existing bugs are possible qualification tasks.
		+
		+	=== DTS / DCA ===
		+
		+	'''Description:''' FFmpeg contains a DTS decoder and an experimental DTS encoder. Both are missing some features.
		+	* DTS-HD decoder improvements: A possible qualification task is to implement ticket #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
		+	* DTS encoder improvements
		+
		+	=== MPEG-4 ALS encoder ===
		+
		+	'''Description:''' An ALS decoder was implemented several years ago, an encoder is still missing.
		+
		+	=== 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 ===
		+
		+	'''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.
		+
		+	=== HEVC / H265 ===
		+
		+	'''Description:''' The specification was finished, FFmpeg needs a decoder for this new format.
		+	* Write a basic decoder supporting I, P, and, only if time permits, B slices.
		+	* It does not need to be ASM/SIMD optimized but its high level structure must permit such optimizations to be easily added later.
		+	As a qualification task you need to implement parsing headers and maybe a bit beyond that to demonstrate that you are qualified and understand the HEVC specification. This project requires a solid understanding of video coding and C, it's not something for the average SOC student.
		+
		+	=== 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.
		+	* Implement missing interlace features
		+	* Make more reference samples bit-exact
		+	As a qualification task, you should try to find a bug in the current decoder implementation and fix it.
		+
		+	=== JPEG 2000 ===
		+
		+	<div class="floatleft">[[Image:Jpeg2000.jpg]]</div>
		+
		+	'''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.
		+	Work on an issue (for example from the bug tracker) as a qualification task to show that you are capable of improving the codec implementation.
		+
		+	<br clear="all">
		+
		+	=== VP7 ===
		+
		+	'''Description:''' Not many VP7 samples are in the wild, but no open-source decoder exists although a specification exists. Write a decoder that reuses as much as possible of existing FFmpeg code, it is likely that functions of the existing decoders for On2-based formats will be useful.

	[[Category:FFmpeg]]		[[Category:FFmpeg]]

FFmpeg Summer of Code 2013

Michael — Wed, 06 Mar 2013 21:59:30 GMT

add myself as mentor /* H264 MVC */

Revision as of 21:59, 6 March 2013		Current revision
Line 76:		Line 76:
	'''Description:''' MVC samples exist, the codec is used on Bluray media, FFmpeg is missing a decoder. Since this task also consists of some changes in the current architecture, it is especially important that this task is discussed on the ffmpeg-devel mailing list.		'''Description:''' MVC samples exist, the codec is used on Bluray media, FFmpeg is missing a decoder. Since this task also consists of some changes in the current architecture, it is especially important that this task is discussed on the ffmpeg-devel mailing list.
	As qualification you have to do some work that demonstrates your understanding of MVC and that is a subpart of the whole MVC implementation.		As qualification you have to do some work that demonstrates your understanding of MVC and that is a subpart of the whole MVC implementation.
		+
		+	'''Mentor:''' Michael Niedermayer

	=== VC-1 interlaced ===		=== VC-1 interlaced ===

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 21:28:37 GMT

/* JPEG 2000 */

Revision as of 21:28, 6 March 2013		Current revision
Line 123:		Line 123:

	=== JPEG 2000 ===		=== JPEG 2000 ===
		+
		+	<div class="floatleft">[[Image:Jpeg2000.jpg]]</div>

	'''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.		'''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.
	Work on an issue (for example from the bug tracker) as a qualification task to show that you are capable of improving the codec implementation.		Work on an issue (for example from the bug tracker) as a qualification task to show that you are capable of improving the codec implementation.
		+
		+	<br clear="all">

	=== VP7 ===		=== VP7 ===

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 21:27:30 GMT

uploaded "[[Image:Jpeg2000.jpg]]"

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 21:26:25 GMT

Add wikipedia random apng to illustrate apng task

Revision as of 21:26, 6 March 2013		Current revision
Line 89:		Line 89:

	'''Specification:''' https://wiki.mozilla.org/APNG_Specification		'''Specification:''' https://wiki.mozilla.org/APNG_Specification
		+
		+	<div class="floatright">[[Image:Animated PNG example bouncing beach ball.png]]</div>

	'''Expected results:'''		'''Expected results:'''

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 21:25:18 GMT

uploaded "[[Image:Animated PNG example bouncing beach ball.png]]"

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 21:22:25 GMT

Add BBB scenes to illustrate video codecs

Revision as of 21:22, 6 March 2013		Current revision
Line 62:		Line 62:

	== Video codecs ==		== Video codecs ==
		+
		+	<center>[[Image:BBB-Scenes.jpg]]</center>

	=== HEVC / H265 ===		=== HEVC / H265 ===

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 21:21:48 GMT

uploaded "[[Image:BBB-Scenes.jpg]]"

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 21:20:56 GMT

uploaded "[[Image:BBB-Scenes.jpg]]"

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 21:14:39 GMT

illustrate audio codecs with an audio spectrum

Revision as of 21:14, 6 March 2013		Current revision
Line 23:		Line 23:

	== Audio codecs ==		== Audio codecs ==
		+
		+	<center>[[Image:Audio_Spectrum.png]]</center>

	=== AAC ===		=== AAC ===

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 21:13:47 GMT

uploaded "[[Image:Audio Spectrum.png]]"

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 21:10:56 GMT

Add opengl logo for glplay

Revision as of 21:10, 6 March 2013		Current revision
Line 128:		Line 128:

	=== glplay ===		=== glplay ===
		+
		+	<div class="floatright">[[Image:Opengl_logo.jpg]]</div>

	'''Description:''' The SDL library that is used by FFplay has some deficiencies, adding OpenGL output to FFplay should allow for better performance (and less bugs at least for some hardware / driver combinations). This could be a new application (glplay), but it is probably simpler to extend ffplay to use OpenGL. You can use code from MPlayer's OpenGL vo module which may be relicensed under the LGPL.		'''Description:''' The SDL library that is used by FFplay has some deficiencies, adding OpenGL output to FFplay should allow for better performance (and less bugs at least for some hardware / driver combinations). This could be a new application (glplay), but it is probably simpler to extend ffplay to use OpenGL. You can use code from MPlayer's OpenGL vo module which may be relicensed under the LGPL.

	'''Mentor:''' TBD Backup: Reimar Döffinger		'''Mentor:''' TBD Backup: Reimar Döffinger
		+
		+	<br clear="all">

	=== Misc Libavfilter extension ===		=== Misc Libavfilter extension ===

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 21:09:49 GMT

uploaded "[[Image:Opengl logo.jpg]]"

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 21:08:42 GMT

Add lavfi illustration

Revision as of 21:08, 6 March 2013		Current revision
Line 134:		Line 134:

	=== Misc Libavfilter extension ===		=== Misc Libavfilter extension ===
		+
		+	<div class="floatright">[[Image:Lavfi-gsoc-filter-vintage-illustration.jpg]]</div>

	'''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.		'''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.
Line 155:		Line 157:
	'''Mentor:''' Stefano Sabatini (''saste'' on IRC). Backup: Clément Bœsch (''ubitux'' on IRC).		'''Mentor:''' Stefano Sabatini (''saste'' on IRC). Backup: Clément Bœsch (''ubitux'' on IRC).

-		+	<br clear="all">
	<div class="floatright">[[Image:Three-two pulldown diagram (telecine).png]]</div>		<div class="floatright">[[Image:Three-two pulldown diagram (telecine).png]]</div>

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 21:05:42 GMT

uploaded "[[Image:Lavfi-gsoc-filter-vintage-illustration.jpg]]"

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 21:01:34 GMT

move ivtc pic a bit up, clear float, move and center sub pic

Revision as of 21:01, 6 March 2013		Current revision
Line 154:		Line 154:

	'''Mentor:''' Stefano Sabatini (''saste'' on IRC). Backup: Clément Bœsch (''ubitux'' on IRC).		'''Mentor:''' Stefano Sabatini (''saste'' on IRC). Backup: Clément Bœsch (''ubitux'' on IRC).
		+
		+
		+	<div class="floatright">[[Image:Three-two pulldown diagram (telecine).png]]</div>

	=== Inverse telecine filter ===		=== Inverse telecine filter ===
Line 168:		Line 171:

	'''Mentor:''' Clément Bœsch (''ubitux'' on IRC). + Derek?		'''Mentor:''' Clément Bœsch (''ubitux'' on IRC). + Derek?
		+
		+	<br clear="all">

	=== Subtitles ===		=== 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 carry an historical burden not easy to deal with, and introduces various issues very specific to its sparse form.		'''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 carry an historical burden not easy to deal with, and introduces various issues very specific to its sparse form.
		+
		+	<center>[[Image:Subtitles-sensei.jpg]]</center>

	'''Expected results:'''		'''Expected results:'''
Line 183:		Line 190:

	'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).		'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).
-
-	[[Image:Subtitles-sensei.jpg]]

	[[Category:FFmpeg]]		[[Category:FFmpeg]]

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 20:54:30 GMT

uploaded "[[Image:Three-two pulldown diagram (telecine).png]]"

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 20:51:57 GMT

/* Other */

Revision as of 20:51, 6 March 2013		Current revision
Line 183:		Line 183:

	'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).		'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).
		+
		+	[[Image:Subtitles-sensei.jpg]]

	[[Category:FFmpeg]]		[[Category:FFmpeg]]

Special:Log/upload

Ubitux — Wed, 06 Mar 2013 20:51:07 GMT

uploaded "[[Image:Subtitles-sensei.jpg]]": Subtitles picture to illustrate the GSOC subtitles task

FFmpeg Summer of Code 2013

Compn — Wed, 06 Mar 2013 20:40:07 GMT

March 29 is the application deadline - add note.

Revision as of 20:40, 6 March 2013		Current revision
Line 1:		Line 1:
	FFmpeg Summer of Code Ideas List		FFmpeg Summer of Code Ideas List
		+
		+	March 29 at 19:00 UTC is the application deadline for interested organizations
		+	Please finish up this page before then.

	= Proposing Ideas =		= Proposing Ideas =

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 20:29:14 GMT

Add inverse telecine filter task

Revision as of 20:29, 6 March 2013		Current revision
Line 151:		Line 151:

	'''Mentor:''' Stefano Sabatini (''saste'' on IRC). Backup: Clément Bœsch (''ubitux'' on IRC).		'''Mentor:''' Stefano Sabatini (''saste'' on IRC). Backup: Clément Bœsch (''ubitux'' on IRC).
		+
		+	=== Inverse telecine filter ===
		+
		+	'''Description:''' Libavfilter has all kind of filters but is really lacking an IVTC one. It's a must-have we have been delaying for too long.
		+
		+	Various very good filters already exists in other projects, notably TIVTC (basically the reference filter), which have been ported/rewritten recently in a portable version (VIVTC). Some other solutions exists in the MPlayer project (something like 4 or 5 filters) but their efficiency is questionable. The VLC project also has its own complete toolkit for inverse telecine which might be interesting to look at, especially for its very complete documentation on the topic.
		+
		+	'''Expected results:''' Write/port a complete and efficient inverse telecine filter to libavfilter.
		+
		+	'''Prerequisites:''' C coding skills, familiarity with git/source code control systems. Some familiarity with the DVD encoding process and the image processing techniques would be a bonus but are not strictly required.
		+
		+	'''Qualification task:''' Make a comparative report about the current filters in various projects (MPlayer, TIVTC, VIVTC, VLC, Handbrake, ...) with all kind of different inputs, notably mixed and badly broken content. This is a very important step that has to be done before writing any code, and will be extremely useful as a future reference.
		+
		+	'''Mentor:''' Clément Bœsch (''ubitux'' on IRC). + Derek?

	=== Subtitles ===		=== Subtitles ===

FFmpeg Summer of Code 2013

Reimar — Wed, 06 Mar 2013 19:57:14 GMT

/* glplay */

Revision as of 19:57, 6 March 2013		Current revision
Line 127:		Line 127:

	'''Description:''' The SDL library that is used by FFplay has some deficiencies, adding OpenGL output to FFplay should allow for better performance (and less bugs at least for some hardware / driver combinations). This could be a new application (glplay), but it is probably simpler to extend ffplay to use OpenGL. You can use code from MPlayer's OpenGL vo module which may be relicensed under the LGPL.		'''Description:''' The SDL library that is used by FFplay has some deficiencies, adding OpenGL output to FFplay should allow for better performance (and less bugs at least for some hardware / driver combinations). This could be a new application (glplay), but it is probably simpler to extend ffplay to use OpenGL. You can use code from MPlayer's OpenGL vo module which may be relicensed under the LGPL.
		+
		+	'''Mentor:''' TBD Backup: Reimar Döffinger

	=== Misc Libavfilter extension ===		=== Misc Libavfilter extension ===

FFmpeg Summer of Code 2013

Ubitux — Wed, 06 Mar 2013 19:16:07 GMT

subtitles: expected results as bullet points

Revision as of 19:16, 6 March 2013		Current revision
Line 148:		Line 148:
	'''Qualification task:''' write or port one or more filter		'''Qualification task:''' write or port one or more filter

-	'''Mentor:''' Stefano Sabatini (''saste'' on IRC).	+	'''Mentor:''' Stefano Sabatini (''saste'' on IRC). Backup: Clément Bœsch (''ubitux'' on 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 carry an historical burden not easy to deal with, and introduces various issues very specific to its sparse form.
		+
		+	'''Expected results:'''
		+	* Write the support for new subtitles formats. Example: a demuxer for .SUP files, just like VobSub but for Blu-Ray.
		+	* Improve text subtitles decoders. Typically, this can be supporting advanced markup features in SAMI or WebVTT.
		+	* Improve the API to facilitates a proper integration of subtitles into libavfilter.
		+
		+	'''Prerequisites:''' C coding skills, familiarity with git/source code control systems. Some background in fansubbing area (notably ASS experience) would be a bonus but is not strictly required.
		+
		+	'''Qualification task:''' write one subtitles demuxer or muxer, and do some improvements to the different layers of the subtitles (to make sure the whole chain is understood).
		+
		+	'''Mentor:''' Clément Bœsch (''ubitux'' on IRC).

	[[Category:FFmpeg]]		[[Category:FFmpeg]]

User:Adam Quantrill

Adam Quantrill — Tue, 05 Mar 2013 18:09:26 GMT

New page

Adam is a computing and electronics engineer currently working in Telecoms, specifically GSM basestations at IP Access Ltd near Cambridge, UK.

Hobbies include engineering, electronics, computing and fine real ale.

AMR-NB

Adam Quantrill — Tue, 05 Mar 2013 18:06:26 GMT

/* GSM OTA format */

Revision as of 18:06, 5 March 2013		Current revision
Line 34:		Line 34:

	== Bit stream frame format ==		== Bit stream frame format ==
-	Specification ([http://www.3gpp.org/ftp/Specs/html-info/26101.htm 26.101]) describes two possible frame types - interface formats 1 and 2 (often abbreviated IF1 and IF2). IF2 is byte-aligned. The following tables of data are taken from this specification unless otherwise stated.	+	Specification ([http://www.3gpp.org/ftp/Specs/html-info/26101.htm 26.101]) describes two possible frame types - interface formats 1 and 2 (often abbreviated IF1 and IF2). IF2 is byte-aligned. The following tables of data are taken from this specification unless otherwise stated. AMR-NB over GSM uses a third slightly different format whose bit-packing is tightly defined by the GSM specs.

	=== IF1 format ===		=== IF1 format ===
Line 91:		Line 91:
	\| Padding (called "Bit stuffing" in the specification)		\| Padding (called "Bit stuffing" in the specification)
	\|		\|
		+	\|}
		+
		+	=== GSM OTA format ===
		+
		+	{\| border=1
		+	! bits !! low level meaning \|\| high level meaning
		+	\|-
		+	\| 4
		+	\| Mode request
		+	\| rowspan=1 \| AMR auxiliary information
		+	\|-
		+	\| 1
		+	\| F bit (0 good/1 unusual)
		+	\| rowspan=3 \| AMR header
		+	\|-
		+	\| 4
		+	\| Frame Type
		+	\|-
		+	\| 1
		+	\| Frame quality indicator (0 bad/1 good)
		+	\|-
		+	\|
		+	\| Class A bits
		+	\| rowspan=3 \| AMR core frame
		+	\|-
		+	\| 6
		+	\| CRC
		+	\|-
		+	\|
		+	\| Class B bits
	\|}		\|}

Line 140:		Line 170:

	* Class A is protected by an 8-bit CRC with polynomial x^8+x^6+x^5+x^4+1 computed over the Class A bits.		* Class A is protected by an 8-bit CRC with polynomial x^8+x^6+x^5+x^4+1 computed over the Class A bits.
		+	* However for AMR-NB over GSM the CRC is a 6-bit with polynomial x^6+x^5+x^3+x^2+x+1 computed over the Class A bits, and it immediately follows the Class A bits, rather than preceding them. That is, it's between the Class A and Class B bits. [see 3GPP TS 05.03 sec 3.9.4.3]
	* There is no significant step-wise change in subjective importance at class boundaries.		* There is no significant step-wise change in subjective importance at class boundaries.
	* The distribution of bits is ordered from most to least subjective importance at both the class level and within the classes.		* The distribution of bits is ordered from most to least subjective importance at both the class level and within the classes.

Talk:SGA

Merlix — Sun, 03 Mar 2013 23:11:11 GMT

New page

===32x File Format===

I disassembled the nt.bin and subload.bin, looks like most of the decoding is done on the 68k side, rather than the sh2 (32x) side.

I will document my curiosities here, for others to read.

==Special Values in decoding==
If the y tile size is 11 then special values are 01 and 03, otherwise its 04 and 02. Havent found where its used yet. But those values pop up all over the compressed data.

LAB_0289:
move #$0003,d3 ;6390: 363C0003
move #$0001,d4 ;6394: 383C0001
cmpi.b #$11,EXT_000D ;6398: 0C390011002018FF
beq.s LAB_028A ;63A0: 6708
move #$0002,d3 ;63A2: 363C0002
move #$0004,d4 ;63A6: 383C0004
LAB_028A:
rts ;63AA: 4E75

==Possible code book setup==
I think this code here is setting up a code book, whats interesting that it seeks to a specific location. Plus there is a specific code book size.

adda.l #$00003004,a0 ;6010: D1FC00003004
movea.l EXT_016B.w,a1 ;6016: 2278AA66
adda.l #$00003020,a1 ;601A: D3FC00003020
move #$1800,d0 ;6020: 303C1800
bsr LAB_0281 ;6024: 610001EC

Scream Tracker 3 Module

Malvineous — Sun, 03 Mar 2013 02:13:53 GMT

/* File Format */ Mention how wide parapointers are

Revision as of 02:13, 3 March 2013		Current revision
Line 8:		Line 8:
	==File Format==		==File Format==

-	The format is little-endian (least significant byte first). A "byte" is 8 bits, a "word" is 16 bits, and a "dword" (double word) is 32 bits. Hex values will be denoted with "0x". A parapointer points to pp*16 in the file due to the DOS nature of the format.	+	The format is little-endian (least significant byte first). A "byte" is 8 bits, a "word" is 16 bits, and a "dword" (double word) is 32 bits. Hex values will be denoted with "0x". A parapointer is 16 bits wide, and points to pp*16 in the file due to the DOS nature of the format.

	Note that if some parts of the format are inconsistent, it's usually best to let it slip, as ST3 itself will allegedly for instance load instruments which don't have the "SCRS" / "SCRI" mark.		Note that if some parts of the format are inconsistent, it's usually best to let it slip, as ST3 itself will allegedly for instance load instruments which don't have the "SCRS" / "SCRI" mark.

User:Compn

Compn — Thu, 28 Feb 2013 18:09:12 GMT

/* unknown codec */

Revision as of 18:09, 28 February 2013		Current revision
Line 184:		Line 184:
	[[User:Dashcloud\|Dashcloud]] 14:23, 20 February 2009 (EST)		[[User:Dashcloud\|Dashcloud]] 14:23, 20 February 2009 (EST)
	HHE1 - zvue video? hhe0 / hhe1 patent : http://www.freepatentsonline.com/y2007/0019741.html . looks like modified mpeg4.		HHE1 - zvue video? hhe0 / hhe1 patent : http://www.freepatentsonline.com/y2007/0019741.html . looks like modified mpeg4.
		+	.
		+	official website in archive hheld.com zvue.com
		+	zflicks 1.5 encodes to xvid, included with ZOrgInstall-1.0.1.exe
		+	all of the -zvue.avi files are created with zflicks 1.1 , but zflicks 1.1 does not include the hhe0 or hhe1 codec. only divx.dll (comes with 1.1) or xvid (comes with 1.5).
		+
		+
	speg - http://qstream.org/ appears to be an Xvid derivative- if you check out the source code, there's a patch mplayer-speg.patch		speg - http://qstream.org/ appears to be an Xvid derivative- if you check out the source code, there's a patch mplayer-speg.patch
	which just tacks SPEG onto all the xvid stuff. [[User:Dashcloud\|Dashcloud]] 14:23, 20 February 2009 (EST)		which just tacks SPEG onto all the xvid stuff. [[User:Dashcloud\|Dashcloud]] 14:23, 20 February 2009 (EST)

Summer of code

Compn — Wed, 27 Feb 2013 18:41:06 GMT

fix redirect

Revision as of 18:41, 27 February 2013		Current revision
Line 1:		Line 1:
-	#redirect [[FFmpeg Summer Of Code]]	+	#redirect [[FFmpeg_/_Libav_Summer_Of_Code]]

FFmpeg Summer of Code 2013

Compn — Wed, 27 Feb 2013 18:38:24 GMT

remove g2m task, 3 months is not enough time to reverse engineer and finish a spec.

Revision as of 18:38, 27 February 2013		Current revision
Line 57:		Line 57:

	== Video codecs ==		== Video codecs ==
-
-	=== GotoMeeting Decoder ===
-
-	'''Description:''' The [[GoToMeeting_Codec]] has been figured out and we need a decoder for it. We don't have samples for G2M1 so this decoder will focus on G2M2, G2M3 and G2M4 versions.

	=== HEVC / H265 ===		=== HEVC / H265 ===