[FFmpeg-devel] [RFC] Google Summer of Code 2013

[Michael Niedermayer]

On Wed, Feb 27, 2013 at 08:41:54PM +0100, Maxim Polijakowski wrote:
> Am 27.02.2013 20:15, schrieb Michael Niedermayer:
> >On Wed, Feb 27, 2013 at 07:29:38PM +0100, Maxim Polijakowski wrote:
> >>Am 27.02.2013 16:55, schrieb Roger Pack:
> >>>On 2/21/13, Lou Logan <lou at lrcd.com> wrote:
> >>>>Hello,
> >>>>
> >>>>It's GSoC time again, so I'll get the ball rolling:
> >>>>http://www.google-melange.com/gsoc/homepage/google/gsoc2013
> >>>>
> >>>>I started a new ideas list:
> >>>>http://wiki.multimedia.cx/index.php?title=FFmpeg_Summer_of_Code_2013
> >>>A few other wish list ideas, if anybody wants to run with them:
> >>I suggest to remove the GoToMeeting entry from this list. It sounds
> >>to me like another project that will never be completed in the GSoC
> >>time frame (3 month). Let me explain why:
> >>
> >>- due to the fact the "decoder specification" has been created in
> >>means of RE, it lacks the desired completeness. One need to dig into
> >>the binary code in order to extract missing parts
> >>
> >>- there is two issues with the ELS coder - the heart of the coding
> >>methods 2 and 3. Go2Meeting utilizes the augmented ELS that combines
> >>the vanilla ELS with a some sort of Q-coder in order to increase
> >>compression. This augmented version has been incompletely documented
> >>by a software patent. No one in the world would be ever able to
> >>reimplement this (weird) entropy coder using this patent alone.
> >>
> >>- fortunately, there is an open-source implementation of this coder
> >>written by the author of this compression method, Mr. Douglas
> >>Whiters. Though this code has been released under the GPL and a
> >>relicensing is required in order to use it within FFmpeg. One need
> >>to contact the author and ask for the appropriate permission. Should
> >>he disagree, we'll end up having another non-free piece of code.
> >>
> >>- FFmpeg's implementation of the JPEG need to be extended to include
> >>tables for Go2Meeting. The attached spec doesn't describe these
> >>tables.
> >quantization and or huffman tables ?
> >are they stored in the files or constant ?
> >
> >if constant and a encoder is available, you can encode the output of
> >-f lavfi mptestsrc
> >the values for the tables can then be inferred from the generated
> >bitstream.
> >The alternative is to find the tables in the binary which may or may
> >not be easier
> 
> Thank you for the suggestions. The tables are constant and I've
> already extracted those from the binary because it's just plain
> libjpeg6b...
> 
> I just wanted to say that the specification made by Kostya (great
> job anyway!) is not sufficient enough to write the decoder from
> scratch. Such "extra" knowledges are essential in order to be able
> to finish the GSoC task...

yes, i agree, both RE + implementation is rather difficult for s gsoc
task 

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Observe your enemies, for they first find out your faults. -- Antisthenes
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