Changes between Initial Version and Version 1 of SponsoringPrograms/GSoC/2016


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Timestamp:
Feb 10, 2016, 5:59:29 PM (5 years ago)
Author:
cehoyos
Comment:

Copy GSoC 2015 into a new 2016 page

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  • SponsoringPrograms/GSoC/2016

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     1[[PageOutline(1-3)]]
     2
     3
     4= Introduction =
     5
     6FFmpeg 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
     7of other software projects in the multi-media field and beyond.
     8
     9This is our ideas page for [http://www.google-melange.com/gsoc/homepage/google/gsoc2015 Google Summer of Code 2015]. See the [http://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2015/help_page#2._What_is_the_program_timeline GSoC Timeline] for important dates.
     10
     11
     12----
     13
     14= Information for Students =
     15
     16== Getting Started ==
     17
     181. '''Get to know FFmpeg.''' If you are a student 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. Also do not hesitate to answer questions from other students on our IRC channel if you know the answer to something.
     19
     202. '''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].
     21
     223. '''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.
     23
     244. '''Apply.''' Students should apply by March 27 at the very latest. The "work" period begins on May 25 and ends in August. Take a look at [http://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2015/help_page#2._What_is_the_program_timeline GSoC timeline] for additional information. Note, make sure you apply to google before the 27th even if you have not yet finished your qualification task.
     25
     26{{{
     27#!div style="border: 1pt dotted; margin: 1em; background-color: #fffff9;"
     28'''Note''': A friendly reminder that while the application to GSoC is important for you and GSoC, FFmpeg mentors will not base their decision solely on the GSoC 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 GSoC's application rules so they can pay you.
     29}}}
     30
     31== Qualification Tasks ==
     32
     33In 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.
     34
     35The 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! Note, please avoid picking a qualification task which another student is already working on, each student should work on a different qualification task.
     36
     37{{{
     38#!div style="border: 1pt dotted; margin: 1em; background-color: #fffff9;"
     39'''Note:''' The running status of this term's qualification tasks is tracked [[2015-Qualis|here]].
     40}}}
     41
     42== Contacting FFmpeg ==
     43
     44If 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:
     45
     46* '''Mailing-list:''' [http://ffmpeg.org/mailman/listinfo/ffmpeg-devel ffmpeg-devel]
     47* '''IRC:''' ''#ffmpeg-devel'' on [http://freenode.net/ Freenode]
     48* '''FFmpeg GSoC Admins:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at), 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)
     49
     50
     51You may also contact a mentor directly if you have questions specifically related to one of the projects listed on this page.
     52
     53----
     54
     55= Mentored Projects =
     56
     57This 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.
     58
     59== AAC Encoder Improvements ==
     60
     61[[Image(wiki:SponsoringPrograms/GSoC/2014:showspectrum.jpg, right, nolink)]]
     62
     63'''Description:''' Currently, FFmpeg contains an experimental native AAC encoder (native meaning that it doesn't depend on external libraries), but it is lacking in terms of extension support, since it currently only implements AAC-LC (the low-complexity profile). Extending feature support of FFmpeg's native encoder is needed to make it competitive with other encoders.
     64
     65    - AAC native encoder missing extensions
     66      - Implement [http://wiki.hydrogenaud.io/index.php?title=Perceptual_Noise_Substitution AAC PNS]
     67      - Implement [http://wiki.hydrogenaudio.org/index.php?title=Joint_stereo#Intensity_Stereo intensity stereo]
     68      - Implement AAC LTP (long term prediction)
     69      - Implement [http://en.wikipedia.org/wiki/Spectral_band_replication AAC SBR] (spectral band replication)
     70
     71'''Qualification Task:'''
     72   - Proof-of-concept PNS. Simplest strategy possible (replace zeroes by noise) and implement bitstream syntax.
     73   - Fix assertion error mentioned in [https://trac.ffmpeg.org/ticket/2686#comment:322 #2686] (ffmpeg_anmr_error2.flac, assertion error on {{{diff >= 0 && diff <= 120}}}).
     74
     75'''Prerequisites:''' C coding skills, basic familiarity with git, knowledge about transform based audio coding are necessary.
     76
     77'''Mentor:''' Claudio Freire (''klaussfreire'' in g mail)
     78
     79'''Backup Mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     80
     81
     82== API regression testing ==
     83
     84'''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.
     85
     86'''Expected results:''' Build a suite of tests for API users, including advanced options such as draw_horiz_band
     87
     88'''Prerequisites:''' Good C coding skills, basic familiarity with git
     89
     90'''Qualification Task:'''  Write a test for a libavcodec decoder using the API
     91
     92'''Mentor:''' Kieran Kunhya(''kierank'' in #ffmpeg-devel on Freenode IRC, kieran[at]kunhya.com)
     93
     94'''Backup Mentor:'''
     95
     96== Animated Portable Network Graphics (APNG) ==
     97
     98[[Image(wiki:SponsoringPrograms/GSoC/2014:animated_PNG_example_bouncing_beach_ball.png, right, nolink)]]
     99
     100
     101'''Description:''' Add encoding support for Animated PNGs. The little bouncing ball animation shown to the right is such an APNG file.
     102
     103'''Specification:''' https://wiki.mozilla.org/APNG_Specification
     104
     105'''Expected results:'''
     106
     107    - APNG muxer & APNG encoder
     108        - use existing PNG encoder code (write encoder in same file)
     109        - write compliant files, make sure they play correctly in major web browsers that support APNG
     110        - Optimally choose blend and dispose op for each frame
     111        - choose offsets and dimension of frame so as to optimize quality per bitrate
     112        - if time permits add lossy png encoding support
     113        - add test for FATE
     114
     115'''Prerequisites:''' C coding skills, basic familiarity with git.
     116
     117'''Qualification Task:''' Write a basic apng encoder that uses APNG_BLEND_OP_SOURCE and offset_x/y=0 which produces valid apng file which can be displayed correctly
     118
     119'''Alternative Qualification Task:''' Improve the filter selection heuristic in the png encoder so files compress better
     120
     121
     122'''Mentor:''' Paul B Mahol (''durandal_1707'' in #ffmpeg-devel on Freenode IRC, onemda@gmail.com)
     123
     124'''Backup mentors:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at), Peter Ross (''pross'' in #ffmpeg-devel, pross@xvid.org)
     125
     126
     127== directshow digital video capture ==
     128
     129'''Description:''' FFmpeg today includes support for windows directshow boxes via creating its own dshow graphs, an internal capture sink, etc.  This had support added recently for things like analog capture devices and analog TV tuners, but lacks support for digital TV tuner capture devices (ATSC etc.) https://msdn.microsoft.com/en-us/library/windows/desktop/dd695354(v=vs.85).aspx
     130
     131The first step will be DVB or ATSC, then vice versa, until it encompasses all the various digital capture options and all parameters for the same.
     132
     133The next step will be creating a libavfilter that can "pass through" frames to be encoded by a windows directshow encoder (for instance, there are some encoders typically only available in windows as dshow devices, like lagarith).
     134
     135Another step would be allowing for "DV capture" (i.e. from a live webcam) viz: https://msdn.microsoft.com/en-us/library/windows/desktop/dd373388(v=vs.85).aspx
     136
     137It would also be nice to refactor the directshow code so that it can take multiple inputs instead of just two today.  Input would look like "-i video=name=Webcam:show_input_video_options=true:framerate=25:audio=name=Audio Device:rate=44100:video=name=Webcam 2:show_input_options=false" etc.
     138
     139Finally, it would be nice to implement the libav "enumerate devices" API to at least show which devices exist on the system.  Initially return just the devices, then return the devices along with any options they have like "name=Capture device:input_crossbar_device_number=3" (one each for each option) as a follow on.
     140
     141'''Expected results:''' It will have the ability to capture video and audio from digital TV tuner devices.  This basically involves setting up the right filter graph and sending it a tuning request, and exposing the output to FFmpeg with the right codecs presented.
     142
     143'''Prerequisites:''' C coding skills, basic familiarity with git, desire to learn, access to windows native box, and eventually, a digital capture device.
     144
     145'''Qualification Task:''' Study all links on digital video capture graphs: http://stackoverflow.com/questions/14150210/having-trouble-capturing-digital-tv-using-directshow and create some test graphs using MSVC graphedit that capture digital video successfully.  Also add an IPersistStream option to and from file for the dshow code base for video basefilter (basically, you can call this to "serialize" it's setting to a file after setting them, and then read them from a file to get back to what they were set to previously).  This also involves a new command line option as well.  ref: http://stackoverflow.com/questions/14050074/how-to-change-directshow-filter-properties-c/27931102#27931102
     146
     147'''Mentor:''' Roger Pack (rogerdpack@gmail.com) the dshow module maintainer.
     148
     149'''Backup Mentor:''' Ramiro Polla (''ramiro'' in #ffmpeg-devel on Freenode IRC, ramiro DOT polla AT gmail DOT com)
     150
     151
     152== FFv1 P frame support ==
     153
     154'''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.
     155
     156'''Expected results:''' State of the art P frame support in the FFv1 encoder and decoder implementation.
     157
     158'''Prerequisites:''' C coding skills, basic familiarity with git, solid understanding of video coding especially with motion compensation.
     159
     160'''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.
     161
     162'''Alternative 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
     163
     164'''Mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     165
     166'''Backup mentor:''' Derek Buitenhuis (''Daemon404'' in #ffmpeg-devel on Freenode IRC, derek.buitenhuis ut gmail)
     167
     168
     169== Postproc optimizations ==
     170
     171[[Image(wiki:SponsoringPrograms/GSoC/2014:PostProc.jpg, 240, right, nolink)]]
     172
     173
     174'''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+).
     175
     176'''Expected results:'''
     177    - Convert all gcc inline asm in libpostproc to YASM.
     178    - Restructure the code so that it works with block sizes compatible with modern SIMD.
     179    - Add Integer SSE2 and AVX2 optimizations for each existing MMX/MMX2/3dnow optimization in libpostproc.
     180
     181'''Prerequisites:''' C coding skills, good x86 assembly coding skills, basic familiarity with git.
     182
     183'''Qualification Task:''' convert 1 or 2 MMX2 functions to SSE2 and AVX2.
     184
     185'''Mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     186
     187'''Backup Mentor:'''
     188
     189
     190== MPEG-4 Audio Lossless Coding (ALS) encoder ==
     191
     192[[Image(wiki:SponsoringPrograms/GSoC/2014:showwaves_green.png, 240, right, nolink)]]
     193
     194'''Description:'''
     195A 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.
     196
     197'''Expected results:'''
     198
     199    - Update the existing encoder to fit into the current codebase.
     200    - Ensure conformance of the encoder by verifying using the reference codec and generate a test case for [http://ffmpeg.org/fate.html FATE].
     201    - Ensure the FFmpeg decoder processes all generated files without warnings.
     202    - Enhance the rudimentary feature set of the encoder.
     203
     204'''Prerequisites:''' C coding skills, basic familiarity with git. A certain interest in audio coding and/or knowledge about the FFmpeg codebase could be beneficial.
     205
     206'''Qualification Task:''' Add floating point support to MPEG-4 ALS decoder
     207
     208'''Mentor:''' Thilo Borgmann (thilo DOT borgmann AT mail DOT de)
     209
     210'''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)
     211
     212== Hardware Acceleration API Software / Tracing Implementation ==
     213
     214[[Image(wiki:SponsoringPrograms/GSoC/2014:hwaccel.jpg, right, nolink)]]
     215
     216'''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.
     217
     218The 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.
     219
     220A 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.
     221
     222'''Prerequisites:''' C coding skills, basic familiarity with git
     223
     224'''Qualification Task:''' Anything related to the hardware acceleration code, though producing first ideas and code pieces for this task would also be reasonable
     225
     226'''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)
     227
     228'''Backup Mentor:''' Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com)
     229
     230
     231== MXF Demuxer Improvements ==
     232
     233'''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.
     234
     235Essence 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.
     236
     237'''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.
     238
     239'''Prerequisites:''' C coding skills, basic familiarity with git. Knowledge of MXF would be useful
     240
     241'''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.
     242
     243'''Mentor:''' Tomas Haerdin (''thardin'' in #ffmpeg-devel on Freenode IRC, tomas.hardin a codemill.se)
     244
     245'''Backup Mentor:''' Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com)
     246
     247
     248== VDPAU filter ==
     249
     250'''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. See the API documentation for more information on some of the features: http://http.download.nvidia.com/XFree86/vdpau/doxygen/html/
     251
     252'''Expected results:''' Implement a filter that allows usage of the postprocessing features as defined by the VDPAU API. This should particularly include the deinterlacer, and ideally all features should be usable to allow comparing the quality and performance of different hardware and hardware vs. software.
     253
     254'''Prerequisites:''' C coding skills, and you will need hardware that allows VDPAU post-processing.
     255
     256'''Qualification Task:''' Show that you are familiar with the FFmpeg filter system by implementing a very simple inverse telecine filter under LGPL that allows reversal of the effect of the telecine filter.
     257
     258'''Mentor:''' Carl Eugen Hoyos (''cehoyos'' in #ffmpeg-devel on Freenode IRC, ce AT hoyos.ws)
     259
     260'''Backup Mentor:''' Reimar Doeffinger (''reimar'' in #ffmpeg-devel on Freenode IRC, Reimar.Doeffinger [at] gmx.de)
     261
     262
     263== Basic servers for network protocols ==
     264
     265'''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.
     266
     267The 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.
     268
     269Note: server support is already implemented for the receiving side of RTSP.
     270
     271'''Expected results:''' basic servers for network protocols capable of interoperating with third-party clients.
     272
     273'''Prerequisites:''' C coding skills, basic familiarity with git, network programming.
     274
     275'''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].
     276
     277'''Mentor:''' Nicolas George (george ad nsup dot org)
     278
     279'''Backup mentor:''' Reynaldo Verdejo (''reynaldo'' in #ffmpeg-devel on Freenode IRC, R Verdejo on g mail)
     280
     281
     282== HTTP/2 ==
     283
     284'''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.
     285
     286'''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.
     287
     288'''Prerequisites:''' C coding skills, basic familiarity with git, network programming.
     289
     290'''Qualification Tasks:'''
     291
     292* Rework current HTTP/1 client code to make it input-driven and support non-blocking mode.
     293
     294* Implement the Websocket protocol on top of the HTTP/1 client code.
     295
     296'''Mentor:''' Nicolas George (george ad nsup dot org)
     297
     298'''Backup mentor:''' TBA
     299
     300
     301== TrueHD encoder ==
     302
     303'''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.
     304
     305'''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
     306
     307'''Prerequisites:''' C coding skills, basic familiarity with git
     308
     309'''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.
     310
     311'''Mentor:''' Ramiro Polla (''ramiro'' in #ffmpeg-devel on Freenode IRC, ramiro DOT polla AT gmail DOT com)
     312
     313'''Backup mentor:''' Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com)
     314
     315== Implement full support for 3GPP Timed Text (movtext, QuickTime) subtitles ==
     316
     317The 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.
     318
     319'''Expected Results:'''
     320- A display window for subtitles can be specified by the user when encoding or transcoding subtitles
     321 - A default window size based on the primary video stream will be implemented
     322- 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
     323 - 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)
     324- Subtitle merging for overlapping subtitles will be implemented
     325
     326'''Prerequisites:''' C coding skills, basic familiarity with git, access to the OS X QuickTime player for playback verification.
     327
     328'''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)
     329
     330'''Mentor:''' Philip Langdale (''philipl'' in #ffmpeg-devel on Freenode IRC, philipl AT overt DOT org)
     331
     332'''Backup mentor:''' Carl Eugen Hoyos (''cehoyos'' in #ffmpeg-devel on Freenode IRC, ce AT hoyos.ws)
     333
     334== Improve Selftest coverage ==
     335
     336'''Description:''' FFmpeg contains many selftests, still more code is not tested than tested thus more such tests are needed
     337to ensure regressions and platform specific bugs are quickly detected. Examples of existing self tests can be seen under #ifdef TEST
     338in various files
     339
     340'''Expected results:''' Significantly improve selftest code coverage
     341
     342'''Prerequisites:''' Good C coding skills, basic familiarity with git
     343
     344'''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
     345
     346'''Mentor:''' Michael Niedermayer (''michaelni'' in #ffmpeg-devel on Freenode IRC, michaelni@gmx.at)
     347
     348'''Backup Mentor:'''
     349
     350== Improve Closed Caption support ==
     351
     352'''Description:''' FFmpeg contains some support for Closed Captions, the goal of this project would be to improve the support.
     353
     354'''Expected results:''' To be defined
     355
     356'''Qualification Task:''' Not yet defined, a starting point would be to look at related tickets:
     357https://trac.ffmpeg.org/query?status=new&status=open&status=reopened&keywords=~+cc&order=priority
     358
     359'''Mentor:''' TBA
     360
     361= Unmentored Projects =
     362
     363This 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 [#YourOwnProjectIdea propose their own project].
     364
     365
     366== Missing AAC decoder features ==
     367
     368'''Description:''' FFmpeg contains an AAC decoder which is missing some features. The task is to rebase existing implementations to the current FFmpeg code-base, test them and fix the remaining bugs.
     369
     370    - AAC BSAC decoder: This has already been started, but the existing decoder still fails on many samples
     371    - AAC SSR decoder
     372    - AAC 960/120 MDCT window
     373
     374'''Qualification Task:''' See the [https://trac.ffmpeg.org/query?status=!closed&keywords=~aac FFmpeg bug tracker for AAC issues], fixing one of them or rebasing the existing incomplete BSAC decoder for current git head and fixing one or more existing bugs are possible qualification tasks.
     375
     376'''Prerequisites:''' C coding skills, basic familiarity with git, knowledge about transform based audio coding would be useful.
     377
     378'''Mentor:'''
     379
     380'''Backup Mentor:''' Reynaldo Verdejo (reynaldo in #ffmpeg-devel on Freenode IRC, R Verdejo on g mail), Sascha Sommer (saschasommer at freenet de)
     381
     382
     383== DTS / DCA Improvements ==
     384
     385'''Description:''' FFmpeg contains a DTS decoder, but its missing several features
     386
     387    - DTS-HD decoder improvements:
     388        - Add support for X96 extension (96khz)
     389        - Add support for pure DTS-HD streams that do not contain a DTS core
     390        - Add support for multiple assets
     391        - Add support for LBR extension
     392
     393'''Prerequisites:''' C coding skills, basic familiarity with git. Good understanding of DTS and related audio coding is a strict requirement.
     394
     395'''Qualification Task:'''  A possible qualification task is to implement ticket [https://trac.ffmpeg.org/ticket/1920 #1920]
     396
     397'''Mentor:'''
     398
     399'''Backup Mentor:''' Stefano Sabatini (''saste'' in #ffmpeg-devel on Freenode IRC, stefasab AT gmail DOT com)
     400
     401
     402== VC-1 interlaced ==
     403
     404'''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.
     405
     406'''Expected results:'''
     407* Implement missing parts of interlacing
     408* Make more reference samples bit-exact
     409
     410'''Prerequisites:''' C coding skills, basic familiarity with git, ability to read and understand the vc1 specification and align that knowledge with the existing code
     411
     412'''Qualification Task:''' Find a bug in the current decoder implementation and fix it.
     413
     414
     415== JPEG 2000 ==
     416
     417'''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
     418
     419'''Expected results:''' A jpeg 2000 decoder which can decode most lossy samples without artifacts and lossless samples exactly.
     420
     421'''Qualification Task:''' Fix an issue (for example from the bug tracker) to show that you are capable of improving the codec implementation.
     422
     423'''Prerequisites:''' C coding skills, basic familiarity with git, good knowledge of Jpeg-2000
     424
     425
     426== Hardware Accelerated Video Encoding with VA-API ==
     427
     428'''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.
     429
     430'''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.
     431
     432   - MPEG-2 encoding:
     433       - Add basic encoding with I/P frames (handle the `-g` option)
     434       - Add support for B frames (handle the `-bf` option)
     435       - Add support for constant bitrate (CBR, i.e. maxrate == bitrate and bufsize set)
     436       - (Optionally) add support for interlaced contents
     437   - H.264 encoding:
     438       - Add basic encoding with I/P frames (handle the `-g` option)
     439       - Add support for B frames (handle the `-bf` option)
     440       - Add support for constant bitrate (CBR, i.e. maxrate == bitrate and bufsize set)
     441       - Add support for constant QP (CQP, i.e. handle the -cqp option)
     442       - Add support for more than one reference frame, while providing/using API to query the hardware capabilities
     443       - Work on HRD conformance. May require to write an independent tool to assess that
     444       - (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.
     445   - FFmpeg applications:
     446       - Define common hwaccel interface for encoding
     447       - Add initial support for hardware accelerated encoding to the ffmpeg application
     448
     449'''Prerequisites:''' C coding skills, basic familiarity with git, hardware supporting VA-API for encoding.
     450
     451'''Qualification Task''': Anything related to the Hardware Acceleration (hwaccel) API, or to its related users. e.g. port VDPAU acceleration to use hwaccel, add JPEG decoding support with VA-API, etc.
     452
     453'''Mentor:''' TBA
     454
     455'''Backup Mentor:''' TBA, possibly Tushar Gohad
     456
     457
     458== H.264 Multiview Video Coding (MVC) ==
     459
     460[[Image(wiki:SponsoringPrograms/GSoC/2014:h264_mvc.jpg, right, nolink)]]
     461
     462'''Description:''' MVC samples exist and the codec is used on Blu-ray media, but FFmpeg is missing a decoder. Since this project also consists of some changes in the current architecture, it is especially important that this project is discussed on the ffmpeg-devel mailing list.
     463
     464'''Expected results:''' Create MVC decoder and add a test for [http://ffmpeg.org/fate.html FATE].
     465
     466'''Prerequisites:''' C coding skills, familiarity with git/source code control systems. Knowledge of H.264 and MPEG-TS would be helpfull
     467
     468'''Qualification Task:''' Perform work that demonstrates understanding of MVC and that is a subpart of the whole MVC implementation.
     469
     470'''Mentor:''' TBA
     471
     472'''Backup mentor:''' TBA
     473
     474== Browsing content on the server ==
     475
     476'''Description:''' libavformat supports network protocols like FTP, SFTP, HTTP.
     477
     478The libavformat framework is able to read, seek and write to files located on server as they were local files. The libavformat is not able to list files nor directories located on remote servers.
     479Your work will be to implement browsing files on remote servers.
     480
     481Note: the libavformat will be prepared with suitable API and only protocol related code will need to be implemented.
     482
     483'''Expected results:''' Application that uses libavformat will be provided with an API to list files and directories (with their attributes like size, creation date, etc) located on remote servers. Implementation for FTP, HTTP and SFTP is required. Optionally file protocol can be also implemented.
     484
     485'''Prerequisites:''' C coding skills, basic familiarity with git, basic knowledge about FTP and HTTP protocols and libssh library.
     486
     487'''Qualification Task:''' Implement browsing routine for one of mentioned protocols (implementation may cover file/directory names only, work with specific servers and under defined conditions).
     488
     489'''Mentor:''' TBA
     490
     491'''Backup mentor:''' TBA, possibly Lukasz Marek (lukaszmluki in #ffmpeg-devel on Freenode IRC, lukasz.m.luki on g mail)
     492
     493== Subtitles ==
     494
     495[[Image(wiki:SponsoringPrograms/GSoC/2014:subtitles_support.jpg, 300, right, nolink)]]
     496
     497'''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.
     498
     499'''Expected results:'''
     500    - Add support for new subtitles formats. Example: a !VobSub muxer, a demuxer and decoder for EBU-TT, or even Kate subtitles (Xiph).
     501    - Improve text subtitles decoders. Typically, this can be supporting advanced markup features in SAMI or WebVTT.
     502    - 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.
     503
     504'''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.
     505
     506'''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.
     507
     508'''Mentor:''' TBA
     509
     510'''Backup Mentor:''' TBA, possibly Nicolas George (''Cigaes'' in #ffmpeg-devel on Freenode IRC)
     511
     512----
     513
     514
     515== Your Own Project Idea ==
     516
     517A student can propose a project. Ideas can also be found by browsing bugs and feature requests on our bug tracker. The work should last the majority of the GSoC internship duration, the task must be approved by the developers, and a mentor must be assigned.
     518
     519Students can discuss an idea in the [https://ffmpeg.org/mailman/listinfo/ffmpeg-devel/ ffmpeg-devel] mailing-list, the #ffmpeg-devel IRC channel, or contact the FFmpeg GSoC admins for more information.