[MPlayer-dev-eng] Proposed changes to af_resample

[Anders Johansson]

> Hi,
> 
> > The basic changes are:
> > 1. If the input and output frequencies are almost the same linear
> >    interpolation is used. The increase in CPU load is negligible (try
> >    it yourself) and it is impossible to hear the errors.
> 
> imho if they are almost same, then no resampling should be done!
> video will play a little bit slower/faster but no one can notice +-1% ...

I am trying to avoid this cause it will mean a redesign of the
automatic filter insertion or an interface redesign or an ugly
hack. Perhaps the best solution is to fix it in
libmpcodecs/dec_audio.c ?
 
> > 2. If input is float or if the user specify float then float
> >    processing is used.
> it's ok
> 
> > 3. int processing and sloppy resampling is enabled by default, and
> >    will be used unless 1. or 2. applies.
> 
> sloppy remple means that it may differ in output freq from the wanted one?

Basically if gcd(fin,fout) > 5000 then allow fout to differ slightly
from the exact value. The reason is that it takes a lot of time to
design a filter that is longer than 5000*L taps (and it eats memory)
up to a minute on a slow machine if fout is big.

> A'rpi / Astral & ESP-team

//Anders