[FFmpeg-devel] FFmpeg Small Task: Optimal Huffman Tables.

Reimar Döffinger Reimar.Doeffinger at gmx.de
Sun Apr 22 19:29:25 CEST 2012

On Sun, Apr 22, 2012 at 08:23:45PM +0530, briggers wrote:
> I expect to have quite a bit of free time over the next few months
> which I hope I can spend constructively by contributing to the
> FFmpeg project. I was looking through the small tasks list on the
> wiki at multimedia.cx [1] to get an idea where I could start. I was
> thinking I could start with the implementation of optimal huffman
> tables for (M)JPEG. I'll try to tread lightly, but I hope you'll
> forgive any future brain farts. Thanks.

Don't worry about mistakes, reviews are there for catching it
(but if you are new it helps if you can forgive if reviews seem/are
a bit harsh, people generally have only time to point out all that
is bad, even if most is good :-) ).
After reading the task I see I may have misunderstood it.
I guess you mean adding a optimal huffman table for each frame
individually (i.e. more the JPEG use case)?
However there are also MJPEG formats that have one huffman table
in the global extradata header, in which case a proper two-pass where
the whole file is encoded first and the optimal table is calculated
only in the second pass is necessary.
But even without that I am not sure this is exactly the most
straight-forward/easy of the tasks listed, but you are very
welcome to do it :-)


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