[MPlayer-dev-eng] [BUG] surround audio plugin broken

Anders Johansson ajh at watri.uwa.edu.au
Mon Jan 6 04:45:12 CET 2003


> On Mon, Jan 06, 2003 at 11:08:14AM +0800, Anders Johansson wrote:
> > Hi,
> > 
> > > Hi,
> > > 
> > > > > > Disagree, resampling when the movie is 48000 hz and the soundcard only
> > > > > > supports 44100 should be done by default, just like -vop scale is
> > > > > > auto-inserted when the output device is rgb. Otherwise the output is
> > > > > > just wrong.
> > > > > 
> > > > > yep. but for example automatic resampling of 44100 to 44098 is just dumb.
> > > > > (and slow and causes big delay and whatever)
> > 
> > Perhaps the sloppy switch in resample should be enabled by default.
> 
> What exactly does sloppy do? 

It reduces the lenght of the required filter by alowing the output
frequency to differ slightly from the requested value.

> > > this way we lose conversions helped by the codecs (examples: liba52's
> > > float2int, channels downsampling, mp3lib's half or quarter freq decoding,
> > > mono decoding of stereo sterams, stereo decoding of mono streams).
> > > but this way we could ask the soundcard to accept the codec's native format,
> > > and do the conversion only if it cannot be done. if both codecs & ao
> > > supports float, then prefer float in filters, otherwise if both codec & ao
> > > are integer, then don't convert it to & back from float, it just eats cpu.
> > > if the user wants hi-fi quality, he can still force float filters on
> > > commandline.
> > 
> > Should I make the filters convert to float depending on the -format switch
> > rather than depending on CPU speed perhaps?
> 
> I think Arpi was saying (and I agree) that filters should NEVER
> convert to float and back unless explicitly requested, or unless a
> filter appears in the chain which cannot handle integer data.

OK, I'll do it.
 
> Rich

//Anders



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