[FFmpeg-devel] [PATCH] j2kenc / openjpegenc: document briefly the differences.

Michael Bradshaw mbradshaw at sorensonmedia.com
Sat Dec 3 19:45:56 CET 2011

>On Sat Dec 03 2011 13:29:08 GMT+0100 (CET), Carl Eugen Hoyos wrote:
>> Nicolas George<nicolas.george<at>  normalesup.org>  writes:
>>> +JPEG 2000.
>>> +
>>> +This encoder is considered experimental (@code{-vstrict experimental}) and
>>> +not actively maintained. Using libopenjpeg instead is recommended, although
>>> +it is slightly slower.
>> "This encoder is slightly faster than libopenjpeg, but still experimental
>> (@code{-vstrict experimental})."
>I'd drop the "slightly" - I have not done any benchmarking but I think
>openjpeg is slow: see http://cuj2k.sourceforge.net/Benchmark.html and

I don't mind whether the "slightly" is there or not, but I don't know
how FFmpeg's j2k encoder stacks up to those other libraries either.
And the speed differences decrease with frame size, and I don't know
how often people encode >20MB frames.

It would be cool to have an encoder that matched CUJ2K in speed
though.  I'd like to multithread the openjpeg encoder someday, which
should help significantly.  Anyway, those are my thoughts.


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