| 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 | | |
| 131 | | The 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 | | |
| 133 | | The 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 | | |
| 135 | | Another 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 | | |
| 137 | | It 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 | | |
| 139 | | Finally, 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 | | |
| 314 | | |
| 315 | | == Implement full support for 3GPP Timed Text (movtext, QuickTime) subtitles == |
| 316 | | |
| 317 | | The 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) |
| 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. |
| | 275 | == H.264 Multiview Video Coding (MVC) == |
| | 276 | |
| | 277 | [[Image(wiki:SponsoringPrograms/GSoC/2014:h264_mvc.jpg, right, nolink)]] |
| | 278 | |
| | 279 | '''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. |
| | 280 | |
| | 281 | '''Expected results:''' Create MVC decoder and add a test for [http://ffmpeg.org/fate.html FATE]. |
| | 282 | |
| | 283 | '''Prerequisites:''' C coding skills, familiarity with git/source code control systems. Knowledge of H.264 and MPEG-TS would be helpfull |
| | 284 | |
| | 285 | '''Qualification Task:''' Perform work that demonstrates understanding of MVC and that is a subpart of the whole MVC implementation. |
| 473 | | |
| 474 | | == Browsing content on the server == |
| 475 | | |
| 476 | | '''Description:''' libavformat supports network protocols like FTP, SFTP, HTTP. |
| 477 | | |
| 478 | | The 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. |
| 479 | | Your work will be to implement browsing files on remote servers. |
| 480 | | |
| 481 | | Note: 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) |
