Changes between Initial Version and Version 1 of SponsoringPrograms/Outreachy/2015-12


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Timestamp:
Oct 14, 2015, 2:30:05 PM (4 years ago)
Author:
michael
Comment:

copy outreachy 2015-5 to -12

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  • SponsoringPrograms/Outreachy/2015-12

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     1[[PageOutline(1-3)]]
     2
     3** This page is a copy from the 2015-5 page, it needs to be updated to be correct for december 2015, please help doing that and once done remove this note **
     4
     5
     6= Introduction =
     7
     8FFmpeg is the universal multimedia toolkit: a complete, cross-platform solution to record, convert, filter and stream audio and video. It is used by a number of media players (including VLC, MPlayer, and Totem through GStreamer), video distribution websites (including !YouTube and Vimeo), Internet browsers (including Google !Chrome/Chromium), and lots
     9of other software projects in the multi-media field and beyond.
     10
     11[http://gnome.org/outreachy/ Outreachy] is a program that helps underrepresented people to get involved in free and open source software. Through the guidance of mentors, interns gain valuable experience interacting with and coding for open source projects like FFmpeg. Additionally, the project and its users benefit from code created from applicants who often continue contributing as developers.
     12
     13This is our landing page for the current round of the program, which will formally start in May, 2015.
     14Please also see our [[SponsoringPrograms/GSoC/2015| Google Summer of Code Page]] for ideas, they are all also eligible and not duplicated here
     15
     16----
     17
     18= Information for Applicants =
     19
     20== Getting Started ==
     21
     221. '''Get to know FFmpeg.''' If you are an applicant interested in contributing to FFmpeg, it is recommended to start by subscribing to the [http://ffmpeg.org/mailman/listinfo/ffmpeg-devel ffmpeg-devel] mailing-list, visiting our !FreeNode IRC channels (''#ffmpeg-devel'' and ''#ffmpeg'' although you will find most developers on the first one), and exploring both the codebase and the development workflow. Feel free to [#ContactingFFmpeg contact us] if you have any questions.
     23
     242. '''Find a project.''' Listed on this page are mentored and un-mentored projects. Mentored projects are well-defined and mentor(s) have already volunteered. Un-mentored projects are additional ideas you may want to consider, but you will have to contact us to find a mentor. You can also propose your own project, if you can think of one that better fits your interest and skill level. If a project description is unclear or you have any questions, please get in touch with its mentor and/or send an email to the program admins at [opw@ffmpeg.org].
     25
     263. '''Contact us.''' If you decide on a project, get in touch with the community and let us know. If you want to work on a qualification task, let the respective mentor know so we can avoid duplicated efforts.
     27
     284. '''Apply.''' Interns should apply by April 7 at the very latest. The "work" period begins May 25 and ends the same day in August. Take a look at [https://gnome.org/outreachy/#apply] for additional information.
     29
     30{{{
     31#!div style="border: 1pt dotted; margin: 1em; background-color: #fffff9;"
     32'''Note''': A friendly reminder that while the application to Outreachy is important for you and Outreachy, FFmpeg mentors will not base their decision solely on the Outreachy application. We will judge the applicant based on their abilities in coding, learning the tools, communication skills etc. So please do not worry about your application being perfect for us. Although it is very important to follow Outreachy's application rules so they can pay you.
     33}}}
     34
     35== Qualification Tasks ==
     36
     37In order to get accepted you normally have to complete a small qualification task. FFmpeg development can be quite challenging and the qualification task helps us figure out whether you are motivated enough and have the potential to deliver successfully.
     38
     39The qualification tasks are 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. In general qualification tasks should include submitting a patch to the ffmpeg-devel mailing list which passes review and is accepted into the FFmpeg codebase. It will be common for such patches to need multiple iterations of submissions and reviews, so dont wait too long with the first submission!
     40
     41{{{
     42#!div style="border: 1pt dotted; margin: 1em; background-color: #fffff9;"
     43'''Note''': Assigned qualification tasks are being tracked [https://trac.ffmpeg.org/wiki/SponsoringPrograms/OPW/2015-05-Qualis here].
     44}}}
     45
     46== Contacting FFmpeg ==
     47
     48If you have questions or comments feel free to contact us via our mailing list, IRC channel, or e-mail one of the FFmpeg Outreachy admins:
     49
     50* '''Mailing-list:''' [http://ffmpeg.org/mailman/listinfo/ffmpeg-devel ffmpeg-devel]
     51* '''IRC:''' ''#ffmpeg-devel'' on [http://freenode.net/ Freenode]
     52* '''FFmpeg Outreachy Admin:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     53* '''FFmpeg Outreachy Backup Admins:''' Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com. ), Reynaldo Verdejo (''reynaldo'' in #ffmpeg-devel on Freenode IRC, R Verdejo on g mail)
     54
     55
     56You may also contact a mentor directly if you have questions specifically related to one of the projects listed on this page.
     57
     58----
     59
     60= Mentored Projects =
     61
     62This 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.
     63
     64
     65== Setting up FATE automated testing system on various platforms ==
     66
     67'''Description:''' Set up virtalboxes with various OSs inside them as well as various qemu based non x86 clients, which run our FATE testset and submit results to fate.ffmpeg.org
     68
     69'''Docs:''' https://ffmpeg.org/fate.html
     70
     71'''Expected results:'''
     72
     73    - several virtualbox images with working fate clients inside them for platforms not yet listed on http://fate.ffmpeg.org
     74    - several non x86 qemu images with working fate clients inside them for platforms not yet listed on http://fate.ffmpeg.org
     75
     76'''Prerequisites:''' POSIX and command line knowledge sufficient to install and setup various odd and obscure operating systems, building and using cross compilers
     77
     78'''Qualification Task:''' create one or 2 working images with fate clients inside them for platforms not yet listed on http://fate.ffmpeg.org
     79
     80'''Mentor:''' Ramiro Polla (''ramiro'' in #ffmpeg-devel on Freenode IRC, ramiro DOT polla AT gmail DOT com)
     81
     82'''Backup mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     83
     84
     85== Creating fate tests / finding sample files to improve fate test coverage ==
     86
     87'''Description:''' Many of our decoders and demuxers are tested but some are not and many are tested incompletely. The goal of the task would be to find small multimedia files which improve this test coverage and add them to the fate tests. Also encoding / muxing / filtering tests can be added to improve coverage
     88
     89'''Docs:''' https://ffmpeg.org/fate.html
     90
     91'''Expected results:''' Significantly improved coverage on http://coverage.ffmpeg.org/, and new tests integrated in "make fate"
     92
     93'''Prerequisites:''' Good knowledge of the Makefile syntax as its used in our fate tests.
     94
     95'''Qualification Task:''' add 3 or 4 fate tests which improve the code coverage of "make fate"
     96
     97'''Mentor:''' Carl Eugen Hoyos (ce at hoyos dot ws)
     98
     99'''Backup mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     100
     101
     102== FFv1 P frame support ==
     103
     104'''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.
     105
     106'''Expected results:''' State of the art P frame support in the FFv1 encoder and decoder implementation.
     107
     108'''Prerequisites:''' C coding skills, basic familiarity with git, solid understanding of video coding especially with motion compensation.
     109
     110'''Qualification Task:''' Improve the compression of the existing FFV1 Intra frames, you can change any part of the algorithm but it must be practical, the more improvement you can achieve, the better
     111
     112'''Mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     113
     114'''Backup mentor:''' Derek Buitenhuis (''Daemon404'' in #ffmpeg-devel on Freenode IRC, derek.buitenhuis ut gmail)
     115
     116
     117== API regression testing ==
     118
     119'''Description:''' FATE is FFmpeg's automated testing suite. However, it only covers users of the ffmpeg executable, and not API users. This means that library users can often have bugs which the ffmpeg executable may hide.
     120
     121'''Expected results:''' Build a suite of tests for API users, including advanced options such as draw_horiz_band
     122
     123'''Prerequisites:''' Good C coding skills, basic familiarity with git
     124
     125'''Qualification Task:'''  Write a test for a libavcodec decoder using the API
     126
     127'''Mentor:''' Kieran Kunhya(''kierank'' in #ffmpeg-devel on Freenode IRC, kieran[at]kunhya.com)
     128
     129'''Backup Mentor:'''
     130
     131
     132== Postproc optimizations ==
     133
     134[[Image(wiki:SponsoringPrograms/GSoC/2014:PostProc.jpg, 240, right, nolink)]]
     135
     136
     137'''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+).
     138
     139'''Expected results:'''
     140    - Convert all gcc inline asm in libpostproc to YASM.
     141    - Restructure the code so that it works with block sizes compatible with modern SIMD.
     142    - Add Integer SSE2 and AVX2 optimizations for each existing MMX/MMX2/3dnow optimization in libpostproc.
     143
     144'''Prerequisites:''' C coding skills, good x86 assembly coding skills, basic familiarity with git.
     145
     146'''Qualification Task:''' convert 1 or 2 MMX2 functions to SSE2 and AVX2.
     147
     148'''Mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     149
     150'''Backup Mentor:'''
     151
     152== MPEG-4 Audio Lossless Coding (ALS) encoder ==
     153
     154[[Image(wiki:SponsoringPrograms/GSoC/2014:showwaves_green.png, 240, right, nolink)]]
     155
     156'''Description:'''
     157A 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.
     158
     159'''Expected results:'''
     160
     161    - Update the existing encoder to fit into the current codebase.
     162    - Ensure conformance of the encoder by verifying using the reference codec and generate a test case for [http://ffmpeg.org/fate.html FATE].
     163    - Ensure the FFmpeg decoder processes all generated files without warnings.
     164    - Enhance the rudimentary feature set of the encoder.
     165
     166'''Prerequisites:''' C coding skills, basic familiarity with git. A certain interest in audio coding and/or knowledge about the FFmpeg codebase could be beneficial.
     167
     168'''Qualification Task:''' Add floating point support to MPEG-4 ALS decoder
     169
     170'''Mentor:''' Thilo Borgmann (thilo DOT borgmann AT mail DOT de)
     171
     172'''Backup Mentor:''' Paul B Mahol (''durandal_1707'' in #ffmpeg-devel on Freenode IRC, onemda@gmail.com), Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com)
     173
     174
     175== Hardware Acceleration API Software / Tracing Implementation ==
     176
     177[[Image(wiki:SponsoringPrograms/GSoC/2014:hwaccel.jpg, right, nolink)]]
     178
     179'''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.
     180
     181The 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 data to allow easy comparison and 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 [https://github.com/apitrace/apitrace apitrace] does for OpenGL.
     182
     183A 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.
     184
     185'''Prerequisites:''' C coding skills, basic familiarity with git
     186
     187'''Qualification Task:''' Anything related to the hardware acceleration code, though producing first ideas and code pieces for this task would also be reasonable
     188
     189'''Mentor:''' Reimar Doeffinger (''reimar'' in #ffmpeg-devel on Freenode IRC, but since I'm rarely there better email me first: Reimar.Doeffinger [at] gmx.de)
     190
     191'''Backup Mentor:''' Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com)
     192
     193
     194== MXF Demuxer Improvements ==
     195
     196'''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.
     197
     198Essence 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 worked and we lack samples demonstrating the contrary.
     199
     200'''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.
     201
     202'''Prerequisites:''' C coding skills, basic familiarity with git. Knowledge of MXF would be useful
     203
     204'''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.
     205
     206'''Mentor:''' Tomas Haerdin (''thardin'' in #ffmpeg-devel on Freenode IRC, tomas.hardin a codemill.se)
     207
     208'''Backup Mentor:''' Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com)
     209
     210
     211== Basic servers for network protocols ==
     212
     213'''Description:''' libavformat contains clients 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.
     214
     215The 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.
     216
     217Note: server support is already implemented for the receiving side of RTSP.
     218
     219'''Expected results:''' basic servers for network protocols capable of interoperating with third-party clients.
     220
     221'''Prerequisites:''' C coding skills, basic familiarity with git, network programming.
     222
     223'''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 ticket in our [https://trac.ffmpeg.org/ bug tracker].
     224
     225'''Mentor:''' Nicolas George (george ad nsup dot org)
     226
     227'''Backup mentor:''' Reynaldo Verdejo (''reynaldo'' in #ffmpeg-devel on Freenode IRC, R Verdejo on g mail)
     228
     229
     230== HTTP/2 ==
     231
     232'''Description:''' the [https://www.mnot.net/blog/2015/02/18/http2 final draft for the HTTP/2 protocol] has been published. It contains various new features that will probably be used to enhance distribution of multimedia contents. Therefore, FFmpeg needs an implementation.
     233
     234'''Expected results:''' HTTP/2 client over TLS and TCP for reading and writing, capable of interacting with stock servers, including using the same connection for simultaneous requests.
     235
     236'''Prerequisites:''' C coding skills, basic familiarity with git, network programming.
     237
     238'''Qualification Tasks:'''
     239
     240* Rework current HTTP/1 client code to make it input-driven and support non-blocking mode.
     241
     242* Implement the Websocket protocol on top of the HTTP/1 client code.
     243
     244'''Mentor:''' Nicolas George (george ad nsup dot org)
     245
     246'''Backup mentor:''' TBA
     247
     248
     249== TrueHD encoder ==
     250
     251'''Description:''' FFmpeg currently does not support encoding to TrueHD, one of the lossless audio formats used on Bluray discs. A nearly functional Meridian Lossless Packing (MLP) encoder has already been written and is available on [https://github.com/ramiropolla/soc/tree/master/mlp github]. The MLP codec is the basis for TrueHD. For this project, that encoder is first to be updated to fit into the current codebase of FFmpeg and to be tested for conformance against Surcode's MLP encoder. Second, the encoder is to be updated to implement TrueHD functionality, allowing it to losslessly encode audio to play it on hardware devices capable of TrueHD decoding. Finally, the encoder is to be brought through the usual reviewing process to hit the codebase at the end of the project.
     252
     253'''Expected results:''' a TrueHD encoder that allows to losslessly encode audio to play it on hardware devices capable of TrueHD decoding with a competetive compression rate
     254
     255'''Prerequisites:''' C coding skills, basic familiarity with git
     256
     257'''Qualification Task:''' Update the MLP encoder so that it produces a valid bitstream that can be decoded by FFmpeg without errors to silence. Find out how to validate the generated bitstream besides using FFmpeg.
     258
     259'''Mentor:''' Ramiro Polla (''ramiro'' in #ffmpeg-devel on Freenode IRC, ramiro DOT polla AT gmail DOT com)
     260
     261'''Backup mentor:''' Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com)
     262
     263== Implement full support for 3GPP Timed Text (movtext, QuickTime) subtitles ==
     264
     265The standard subtitle format used in MP4 containers is 3GPP timed text, as defined in [http://www.3gpp.org/DynaReport/26245.htm 3GPP TS 26.245]. It is the only subtitle format supported in Apple's media players on OS X and iOS, and the only format that's part of the mpeg4 standard. As such it is important for FFmpeg to support the format as fully as possible. Currently, it supports a limited subset of the format without any rich text formatting or the ability to position text on the screen. For this project, the goal would be to implement complete support for these features and have the implementation fully reviewed and merged into FFmpeg.
     266
     267'''Expected Results:'''
     268- A display window for subtitles can be specified by the user when encoding or transcoding subtitles
     269 - A default window size based on the primary video stream will be implemented
     270- As much text formatting metadata as can be expressed in ASS will be supported for both transcoding to and from timed text, including positional metadata
     271 - The OSX QuickTime player should be used to evaluate the behaviour of formatting metadata. (This appears to be the most feature complete player with respect to the formatting features of 3GPP Timed Text)
     272- Subtitle merging for overlapping subtitles will be implemented
     273
     274'''Prerequisites:''' C coding skills, basic familiarity with git, access to the OS X QuickTime player for playback verification.
     275
     276'''Qualification Task:''' Implement support for transcoding bold, italic, and underline formatting to and from ffmpeg's internal ASS format. (Will require temporary patches (which already exist) for display window sizing/positioning)
     277
     278'''Mentor:''' Philip Langdale (''philipl'' in #ffmpeg-devel on Freenode IRC, philipl AT overt DOT org)
     279
     280'''Backup mentor:''' Carl Eugen Hoyos (''cehoyos'' in #ffmpeg-devel on Freenode IRC, ce AT hoyos.ws)
     281
     282== Improve Selftest coverage ==
     283
     284'''Description:''' FFmpeg contains many selftests, still more code is not tested than tested thus more such tests are needed
     285to ensure regressions and platform specific bugs are quickly detected. Examples of existing self tests can be seen under #ifdef TEST
     286in various files
     287
     288'''Expected results:''' Significantly improve selftest code coverage
     289
     290'''Prerequisites:''' Good C coding skills, basic familiarity with git
     291
     292'''Qualification Task:'''  Improve selftest code coverage by at least 1% of two of the main libs (libavcodec, libavformat, libavdevice, libavfilter, libavutil, libswresample, libswscale) as listed at http://coverage.ffmpeg.org/index.html
     293
     294'''Mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     295
     296'''Backup Mentor:'''