Rémi Denis-Courmont <[email protected]> writes: > On Tue, 15 Sep 2009 22:18:22 +0100, Måns Rullgård <[email protected]> wrote: >>> Attached is an intial patch against libmpeg2 trunk to use NEON for >>> motion compensation. This is preliminary. There are a bunch of known >>> CPU stalls. Those could probably be fixed using plain assembly and >>> interleaving subsequent loads. Also, iDCT is not optimized. >> >> Why don't you steal the functions from FFmpeg instead? They are much >> better optimised than this patch. > > FFmpeg-based MPEG2 decoding was so slow on the target, that I did not even > consider the possibility that it might have been optimized. For whatever > reason, it is (eye-)noticeably slower than current libmpeg2 with the > non-SIMD ARM optimizations. Why is this so? I do not know. There could be > something wrong with VLC, but then again the FFmpeg h.264 decoding is > accelerated fine. Or it could be a build problem, or it could be that I did > not test properly, or it could be a FFmpeg problem in other part.
I have compared FFmpeg against libmpeg2 myself, and FFmpeg on ARMv7 is about 1.5x faster than libmpeg2. If your experience with VLC is to the contrary, there must be a problem in VLC. -- Måns Rullgård [email protected] ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ Libmpeg2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmpeg2-devel
