[FFmpeg-devel] GP License question

Carl Eugen Hoyos cehoyos at ag.or.at
Tue Mar 22 16:47:52 CET 2016

Aaron Boxer <boxerab <at> gmail.com> writes:

> In fact, I couldn't find many j2k issues in trac.

I see too many:

> Does your codec take advantage of multiple cores?

Fortunately not: Since jpeg 2000 is an intra-only codec, 
using multiple cores to decode / encode several frames at 
the same time is possible and has a significantly lower 
overhead than implementing wavefront or slice-based 
multithreaded encoding or decoding.

Last time I tested the native codec was faster than 
openjpeg on a single core.

> Or is it only single threaded?

> Because this is one of the chief reasons for OpenJPEG 
> being slow as molasses.

I don't understand: It is possible (and FFmpeg does it) to 
use multi-threading when using Openjpeg but since this is 
possible with all intra-only (and therefore all jpeg 2000) 
codecs it does not make it faster than any of its rivals.

Are you interested in working on FFmpeg's jpeg2000 
implementation? If not, please consider to promote ronin 

Carl Eugen

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