[FFmpeg-devel] [PATCH 2/5] fate: avoid framemd5, use framecrc its faster

[Reimar Döffinger]

On Thu, May 16, 2013 at 09:36:02PM +0000, Paul B Mahol wrote:
> On 5/16/13, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Thu, May 16, 2013 at 08:35:32PM +0200, Nicolas George wrote:
> >> Le decadi 20 floreal, an CCXXI, Michael Niedermayer a ecrit :
> >> > hmm, i get:
> >> > ffmpeg -f rawvideo md5:  user    0m2.212s    sys 0m0.428s
> >> > ffmpeg -f md5 -          user    0m2.192s    sys 0m0.408s
> >> > ffmpeg -f crc -          user    0m0.356s    sys 0m0.408s
> >> > ffmpeg -f null -         user    0m0.008s    sys 0m0.084s
> >> > aviocat md5:             user    0m2.004s    sys 0m0.108s
> >> > gnu md5sum               user    0m1.272s    sys 0m0.116s
> >> > ffadler                  user    0m0.164s    sys 0m0.060s
> >> >
> >> > Note, my ffmpeg tests did read the random file as if it was
> >> > rawvideo (which it was not) no real demuxing thus done
> >> > test done with a random 900mb file on sandybridge i7 4ghz
> >>
> >> It is hard to reproduce your runs, and the framework overhead may make
> >> comparison less relevant.
> >>
> >> I have written a small benchmark for various hash functions, I can send
> >> the
> >> program itself if wanted, and the results are below (the time is in
> >> cycles
> >> per byte).
> >>
> >> You will notice that OpenSSL is always faster than lavu; the difference
> >> is
> >> negligible for SHA-2 on x86_32, but elsewhere it is significant, and it
> >> is
> >> even huge for MD5 on Atom, for some reason.
> >
> > under which license is the openssl code ? if its lgpl we should
> > consider replacing ours by the openssl code. If not borrowing its
> > tricks would make sense
> 
> its bsd license

Unless something changed it is not compatible with any LGPL or GPL
license though.