[MPlayer-dev-eng] [PATCH] fix for -srate bug

[Michael Niedermayer]

Hi

On Wednesday 20 October 2004 00:35, Ed Wildgoose wrote:
> Michael Niedermayer wrote:
> >to answer the question, how does libavcodecs resampler perform, i added
> >support for it in that test proggy, see attached diff & output
> >i also had to change the rolloff calculation, as it searched for the 3db
> >attenuation during upsampling and libavcodec doesnt have such a large
> >attenuation during upsampling, so it does the test with downsampling now
> >
> >summary:
> >lavc is at least twice as fast as the fastest converter from libsamplerate
> >(the benchmark routine should be replaced with rdtsc to find out by how
> > much exactly, it could be much more)
> >the -3db rolloff point of lavc is at 92.70 %, the one from the best
> > converter of libsamplerate is at 96.94 % and the second best is at 90.66
> > %
> >the SN ratio of lavc is 68.05 dB while libsamplerates 3 best converters
> > are around 100 db and the 2 remaining at 10-20, the reason for the lower
> > SN ratio is almost certainly caused by the 16bit in/output used in lavc
> > while libsamplerate uses floats
> >
> >[...]
>
> Hmm, thanks Michael!  This is a very interesting test!  It would have
> been beyond me to whip up such a comparison in such a short time.
>
> Can I just confirm that what you have done is the equivalent of using
> "mplayer -af resample=blah"?  I just want to be sure that I am comparing
> like with like?

[...]

>
> The -3db rolloff point of lavc seems pretty good as well.  However, the
> SN ratio seems pretty poor..  All I can say having only done some quick
> listening tests is that the mplayer high quality resampling doesn't have
> the annoying buzzing sounds, but it does sound a little different, and
> things like human voices are a little bit harder to make out and a
> little muffled.  It's not enough to instantly say that it sounds
> horrible, but there is something just not quite right there?

mplayer does currently _NOT_ use libavcodec for resampling 

[...]
-- 
Michael

"I do not agree with what you have to say, but I'll defend to the death your
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