[Ffmpeg-devel] [RFC] svq1 very slow encoding

Michael Niedermayer michaelni
Fri Mar 30 01:35:26 CEST 2007


Hi

On Thu, Mar 29, 2007 at 04:18:58PM -0600, Loren Merritt wrote:
> On Thu, 29 Mar 2007, Baptiste Coudurier wrote:
> >Mike Melanson wrote:
> >>Baptiste Coudurier wrote:
> >>>
> >>>I just noticed that svq1 encoding was slow as hell (around 2fps here on
> >>>p4 2.4ghz), if someone had spare time/motivation to speed it up, it
> >>>would be great.
> >>
> >>SVQ1 stands for Sorenson Vector Quantizer #1. Are you sure you
> >>understand how vector quantizers operate? By nature, they are
> >>excruciatingly slow to encode, yet relatively blindingly fast to decode.
> >
> >Well, I don't know, it seems quicktime player here explodes ffmpeg
> >encoder performance (561s for 760 frame long movie, which is less than
> >2fps).
> >
> >Quicktime takes like 4 minutes and achieve 4mbit/s, quality is clearly
> >below of course, but it's clearly faster.
> 
> 65% of the cpu time was spent on one line. Clearly a candidate for simd.
> 
> Patch makes the encode 2.3x faster on a athlon64. Additional speedups I 
> tried but didn't include here: using inline instead of dsp adds another 
> 10%, and 3dnow adds 3%.

great, patch looks ok

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The greatest way to live with honor in this world is to be what we pretend
to be. -- Socrates
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20070330/e594389c/attachment.pgp>



More information about the ffmpeg-devel mailing list