Summer of Code 2008

DRAFT

This is a draft proposal for Google Summer of Code projects with Xiph.org.

We need a primary and backup mentor volunteer for any project that is to become an official proposal.

Optimize Theora encoding/decoding speed, SSE/SSE2

Work on MMX, SSE/SSE2 implementations of the crucial encoding and decoding elements in libtheora. This could continue in theora-exp where with ruik's work or consolidate theora-mmx, theora-oil work into trunk. The results must still build cleanly on other archs and do run-time capability detection.

Mentor: Ralph Giles, backup: Jan Gerber, Mike Smith

Theora reference encoder quality optimization

The libtheora encoder could make more use of some features present in the spec but not currently implemented in the encoder. This is a little open ended, but suggestions are: quant matrix tuning, per-block qi choice, 4:2:2 and 4:4:4 chroma support.

Mentor: Ralph Giles, backup: Timothy Terriberry

Encode support in theora-exp

Implement a rate-distortion optimized encoding mode for theora-exp, including R-D optimzed mode decision and quantization (e.g., constant lambda). Then, use the above routines to implement a medium-latency ABR encoding mode (e.g., varying lambda), with a default target buffer size of approximately 2 seconds.

Mentor: Timothy "Derf" Terriberry, backup: Mike Smith, Ralph Giles

Development assistant for the "Ghost" audio codec

Designing a cutting edge perceptual codec is a very daunting task. Xiph is in the research stage on a new low-latency, general purpose audio codec, code-named "Ghost". This is basically a "code assistant" position, where you will be asked to implement, test, and give feedback on ideas from Christopher Montgomery, designer of the Ogg Vorbis format. Be prepared to learn a lot about audio coding, or apply what you already know. While there's less "ownership" potential in this project proposal, it will be a great opportunity to learn about compression algorithm design, practice your programming chops, and learn to work in team.

Mentor: Christopher "Monty" Montgomery, backup: Jean-Marc Valin

OggMNG implementation

Implement the OggMNG decode support in gstreamer and/or illi's dshow filters. Implement encoding support in based on byzanz or istambul. Bonus points for overlay support.

Mentors: Mike Smith, Ralph Giles

Subtitle Editor

this project would also consolidate the various proposals for subtitles. from what i saw on #annodex, using CMML might be the way to go. Coordinate with Annodex.net.

another option is to pick an existing format (e.g. srt) and get a gui mockup done. It should: give you playback with scrubbing, let you set in and out points, and write out the results in an Ogg File.

OggSkeleton tool support

Implement OggSkeleton production in various xiph tool packages. Also implement some playback support at least one popular playback framework: illi's dshow filters, gstreamer/totem, VLC, Quicktime, etc.

Mentor: Conrad Parker, backup: Silvia Pfeiffer

MXF support in gstreamer

Implement an MXF mux/demux for gstreamer, with mappings for Vorbis and Theora. This should probably be a gstreamer project instead.

Mentors: Christian Schaller, Mike Smith

Hardware implementation of Theora decoding

Working on a hardware theora decoder, that can be used in embedded devices, dvd players and video pods. Presumedly GPL verilog source to run on an FPGA.

Intel to AT&T x86 assembly translation

There is a general need for cross platform projects to be able to compile the same asm accelleration code on both GCC and MSVC. Unfortunately, at least of x86, they have incompatible assembly formats. Currently people either convert one to the other by hand (a maintenance nightmare) or require an external compile/assemble step on one or the other platform.

Start with the (unmaintained?) intel2gas script. Spruce it up to support all of recent MMX, SSE, SSE2, SSE3 instructions. Then implement the reverse translation. Once both are working, write some glue code so it can be easily used as part of a GNU autotools build to derive one set of source from the other at build or package time.

RTP payloaders and depayloaders for Vorbis and Theora

Write a set of payloaders and depayloader plugins for Vorbis and Theora for GStreamer and Farsight. These plugins should implement the current specifications for Vorbis and Theora. Philipe Khalaf and Rob Taylor of the Farsight project are prepared to mentor this project.

Mentors: Philipe Khalaf, Rob Taylor Backup: Christian Schaller