[Ffmpeg-devel] patch: altivec optimizations for h264 decoder

[Diego Biurrun]

On Mon, Feb 06, 2006 at 11:24:14AM +0100, Mauricio Alvarez wrote:
> 
> As a part of my academic research on architectures for video
> decoding I am doing some optimizations to the h.264 decoder for the ppc
> architecture using altivec, and I want to submit them back to the ffmpeg
> project.

One of the patches does not apply cleanly anymore:

cerebus:~/src/ffmpeg/libavcodec/ppc$ patch --dry-run -p0 -i
/tmp/patch1.txt 
patching file dsputil_h264_altivec.c
Hunk #2 FAILED at 322.
1 out of 7 hunks FAILED -- saving rejects to file
dsputil_h264_altivec.c.rej

Also, please create the patches from the root of the source tree, it's
easier to handle them this way.

> iv) I have performed a regresion test and the new optimizations passed
> it ok. Also I have decocoded some videos[2] coded with the JM and x264
> encoders at HD resolution and all of them decode well.
> The speed-ups for the sequences used is described in the next table:

Have you tried Linux on PPC as well?  It does appear to work, but since
H.264 with AltiVec produces heavy artifacts, it's hard to tell if the
artifacts are worse or not.

Diego

P.S.: Please don't start threads by replying to existing messages, it
breaks proper threading, thanks.