[FFmpeg-devel] Behaviour of liba52 decoder

[Michael Niedermayer]

On Thu, Jan 10, 2008 at 06:54:13PM +0000, M?ns Rullg?rd wrote:
> Michael Niedermayer <michaelni at gmx.at> writes:
> 
> > On Thu, Jan 10, 2008 at 01:36:31PM -0500, Rich Felker wrote:
> >> On Thu, Jan 10, 2008 at 06:28:52PM +0000, M?ns Rullg?rd wrote:
> >> > Rich Felker <dalias at aerifal.cx> writes:
> >> > 
> >> > > On Thu, Jan 10, 2008 at 12:57:33PM +0100, Thorsten Jordan wrote:
> >> > >> Michael Niedermayer schrieb:
> >> > >> > Hi
> >> > >> > 
> >> > >> >> any comments?
> >> > >> > 
> >> > >> > a52_decode_frame() looks buggy yes ...
> >> > >> > i suggest you rewrite it ...
> >> > >> > 
> >> > >> > it should roughly look like
> >> > >> > 
> >> > >> > read header
> >> > >> > for(all 6 block)
> >> > >> >     decode block
> >> > >> this would be ok if one could demand that full frames are given always.
> >> > >
> >> > > All lavc decoders are entitled to assume this.
> >> > 
> >> > I'm surprised nobody has mentioned the fact that we now have a native
> >> > AC3 decoder, so there is no longer any need for the liba52 wrapper.
> >> > Is there some reason I'm missing why it's still there?
> >> 
> >> Good question. I'd be happy to see it removed.
> >
> > if ours is faster sure remove liba52 support ...
> 
> Is speed the only deciding factor here?  I suppose I could benchmark
> decoding a DVD or two.

The question is probably if we have volunteers to do more complete testing
that is
* .o size
* memory requirement
* as already mentioned speed
* quality (are there specific tests mandated by the ac3 spec?)
* feature completeness (i assume we are better especially with EAC3 around
  the corner and liba52 being not very actively developed lately AFAIK)
* error concealment (being mandatory for EAC3 we should be as good or better
  here as well eventually)

Anyway speed tests alone would already be very interresting
C and SSE of course for both

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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