Libav Summer Of Code 2012
How it works
Google's Summer of Code program is simple: you (the student) work on a project, full-time, during the whole summer, and you get assistance (advice, mentoring) from a seasoned FFmpeg/Libav developer who knows his way around the project and has considerable standing in the community. By doing so, you'll learn to operate in an opensource project, you'll get relevant coding experience, and you'll have a chance at earning money while doing fun stuff during the summer. So, you need a project, a mentor, do a qualification task (see below) so we can quickly assess how good a candidate we feel you'll be for the program, and then you can apply.
- Please detail the deadlines for applying and being a student/mentor.
Selecting a project
Below, you'll find two lists of projects:
- Projects with a mentor
- Projects without a mentor
If you choose a project with a mentor, talk to that mentor (see below) and select a suitable qualification task. Once completed, you're eligible for participating in our Summer of Code program. If you choose a project without a mentor, your first job is to find a mentor (see below). Then, once you've found a mentor, continue as before. If you don't like any of the projects, you're free to define your own project and find a mentor as mentioned before (see below for caveats).
Once you've found a project (with or without mentor), start talking to the developers of the FFmpeg and Libav projects. We can often be found on IRC, and you can talk to us on mailinglists also. Hop on irc.freenode.net channels #ffmpeg-devel or #libav-devel, or talk to us on firstname.lastname@example.org or email@example.com. (At this point, you're probably wondering why there are 2 IRC channels and 2 mailinglists. Ask your mentor, it'll make for a good first conversation topic.) Here, you'll be able to ask around for mentors for projects without a mentor if you need to. If you're trying to define your own project, explain (with reasonable amount of detail) what you intend to achieve and why you think your project should be in our Summer of Code program. Once you've found a mentor, you're good to start your qualification task.
Note that the self-selected mentor needs to have considerable standing in the community to be eligible for mentoring. Likewise, if you choose to define your own Summer of Code project, some community members of considerable standing need to vouch for your project.
Your qualification task
The goal of a qualification task is to see if the mentor and student feel that, together, they will be able to finish the project of their choice. More specifically, the mentor will want to test whether the student has the skills and work ethics to complete a large coding project in a limited amount of time. The student will want to make sure that the mentor provides (useful) assistance when necessary. Therefore, students should select a mentor and a Summer of Code project before starting their work on a qualification task. The qualification task is often (but not necessarily) related to the selected project. For example, if your project will be to reverse engineer a new video codec, the qualification task may be to write a partial bitstream parser for that codec. If your project is to write a muxer for a container format, the qualification task may be to write the code to write the stream header.
There will be a second qualification task for every student: Pick a file of moderate size and reformat it in proper K&R style. The goal of this task is twofold: First it familiarizes students with the style that they will have to write their code in, second it demonstrates that students are able to submit patches from git and go through our review process.
While you're working on your qualification task, apply at http://www.google-melange.com/. The degree (and detail) with which you've finished your qualification task will determine how likely your project is to be selected. In the past few years, students that completely finished their qualification task always got selected as Summer of Code students, but that may vary depending on the number of spots we get assigned by Google, and the number of students that apply.
1st Tier Project Proposals
1st tier project proposals are project ideas that are reasonably well defined AND have a mentor volunteered.
- HEVC is the next-generation video standard from the MPEG standards committee. Your job is to write a decoder that can playback HEVC files.
- It does not need to be SIMD-optimized, but preferably has relevant functions separated in DSP contexts so they're easy to optimize later on.
- This task will depend on the current standardisation status of HEVC. Final publication is in 2013 but there may be parts which will not change much anyway.
Mentor: Ronald S. Bultje
- ETSI released specifcations (http://www.etsi.org/deliver/etsi_ts/102100_102199/102114/01.03.01_60/ts_102114v010301p.pdf). Your job is to complete the existing decoder with the following features.
(1) Add support for mixed Core + DTS-HD stream structure (DtsCoreFrame+DtsHdFrame+DtsCoreFrame+DtsHdFrame+...), used by Blu-Ray main and commentary tracks. (2) Add support for XXCh extension (6.1 and 7.1 channels). (3) Add support for X96 extension (96khz). (4) Add support for XLL extension (lossless). (5) Add support for a pure DTS-HD stream structure (DtsHdFrame+DtsHdFrame+DtsHdFrame+...), used by Blu-Ray PiP tracks. (6) Add support for XBR extension (extra bitrate).
Mentor: Benjamin Larsson
MPEG-4 ALS Roundup
This task is to update and enhance the existing ALS decoder as well as integrate and enhance the rudimentary encoder found at: https://github.com/justinruggles/FFmpeg-alsenc
Possible features are:
- implement rls-lms in the decoder
- do correct channel layout/sort handling in the decoder
- update to current master
- use codec private options
- implement encode2(), setting pts and duration
- document options and examples in encoders.texi
- come up with a good set of encoding tests for FATE
- implement mcc/channel sort in the encoder
- implement rls-lms in the encoder
- implement float support
Mentor: Justin Ruggles
On2 VP7 decoder
VP7 is a DCT-based video codec. At the moment, it seems to lack a reference implementation, but we do have a spec and may take hint from libavcodec's VP8 and VP6 decoder and libvpx. MPlayer can decode VP7 by loading a binary. To begin working on the project, one has to setup a reference decoder against which to compare our output. This can be done by either writing a wrapper for the binary or (maybe) hacking libvpx itself.
You might want to discuss with us how and where to start. Drop by on IRC if you need help. It is not as difficult as it sounds.
Mentor: Mashiat Sarker Shakkhar
RTMP[E|S|T|TE] protocol implementation
Currently librtmp is required for RTMPE, RTMPS, RTMPT, RTMPTE. The goal of this project is to implement these protocol variants natively in libavformat.
Mentor: Martin Storsjö
spin off build system into a separate project
Our build system is neat enough to make into a more general solution to be reused by other projects.
The goal of this project is to achieve exactly that. Intermediate steps will be reading, understanding and documenting the current build system, refactoring parts that can be generalized further and finally making a prototype implementation for libpostproc.
You will require skills in POSIX shell, GNU Make and a firm command of English.
Mentor: Diego Biurrun
Improve the audio resampling/rematrixing/converting code
- right now, we're using libswresample to resample/rematrix audio (samplerate / channels) and to resample the audio format (int, float, 16-bit, 32-bit).
- both interleaved and planar audio sample formats are already supported
- We need SIMD optimization of popular conversions (float-int16, int16-float), (stereo-mono-5.1) and anything else thats frequently used.
- We need support for alternate conversion functions (e.g. sample format conversion with or without dithering)
- fix bugs in current design (none known but there sure are some)
Mentor: Michael Niedermayer
2nd Tier (need mentor) Project Proposals
- this task is to get libbluray integrated and working with as many discs as possible.
- Add the ability to encode and decode using Advanced Access Content System.
- Specifications: http://www.aacsla.com/specifications/
- existing implementation e.g. DumpHD: http://forum.doom9.org/showthread.php?t=123111
- Most parts (BD-J, MKB, title key generation) probably do not belong in libavcodec/libavformat, this should be discussed with us before submitting an application
- possible solution: only implement "lowest" level (decode given the correct title key) but implement CSS en- and decryption as secondary goal