[FFmpeg-devel] [PATCH] unscaled float 2 int conversion

[Michael Niedermayer]

On Sun, May 18, 2008 at 12:12:04AM +0200, Benjamin Larsson wrote:
> [...]
> >> so how should we go forward from this when we work on 
> >> implementing a new audio api. The codecs should output samples in their 
> >> native format, that is what I think most of us agree on. But what is the 
> >> native format for a codec outputting samples in float when running in 
> >> simd mode and the same when running in non simd mode ?
> > 
> > SAMPLE_FMT_FLT
> > and
> > SAMPLE_FMT_FLT_BIAS_385
> 
> The reason I keep bitching about this is that SAMPLE_FMT_FLT_BIAS_385
> output is cumbersome to use if you want to add a filter after you have
> decoded a codec frame.

I do not understand this problem. Each filter (if we ever do have audio
filters) supports specific formats and convertion filters would be
insterted as needed.
Only the convertion filter needs to care about SAMPLE_FMT_FLT_BIAS_385.


> 
> What I propose then is that we only use the bias trick when we are
> outputting 16bit samples directly after the decoder.

Of course, thats the whole idea behind SAMPLE_FMT_FLT_BIAS_385.
Also the second last filter might choose to output SAMPLE_FMT_FLT_BIAS_385
if it knows that the next filter prefers it and converts to 16bit.

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Observe your enemies, for they first find out your faults. -- Antisthenes
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