[FFmpeg-devel] [PATCH] HE-AAC v1 decoder try 4
Thu Feb 25 05:06:08 CET 2010
On Wed, Feb 24, 2010 at 10:31:43PM -0500, Alex Converse wrote:
> On Wed, Feb 24, 2010 at 9:20 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Wed, Feb 24, 2010 at 07:36:53PM -0500, Alex Converse wrote:
> >> On Tue, Feb 16, 2010 at 6:19 PM, Alex Converse <alex.converse at gmail.com> wrote:
> >> > On Tue, Feb 16, 2010 at 6:01 PM, Alex Converse <alex.converse at gmail.com>
> >> > wrote:
> >> >>
> >> >> Notes:
> >> >> *All the computation time is spent in ff_sbr_apply() and it's
> >> >> children. If it isn't called from ff_sbr_apply() making it 100% faster
> >> >> isn't going to buy us anything.
> >> >> *Right now the synthesis filterbank is written on top on an MDCT. With
> >> >> appropriate SIMD functions it may make sense to move it to an FFT.
> >> >> Right now the MDCT version is much faster.
> >> >> *SIMD placeholder patch not included
> >> >
> >> > Wrong patch.
> >> > try 4.1 :)
> >> Since the last patch I beat on the decoder with the zzuf hammer and
> >> fixed a few minor things as well as addressing the feeback I've seen
> >> in this thread.
> >> So I'm trying to figure out where we stand on this:
> >> *Does the ffplay issue block this?
> > what ffplay issue?
> The sample rate gets set late and ffplay winds up playing back at its
> default sample rate, as discovered by Vlad earlier in this thread.
id say move the sample_rate=0 from the codec init to av_find_stream_info()
if(aac) sample_rate=0; //elaborate comment
just an idea, maybe theres something cleaner ...
strictly speaking, all demuxers that set a wrong sample_rate are broken
(sample_rate is defined by math since a very long time. specs cannot
redefine it for their shitty hacks, but then the whole .mp4 spec is a
huge hack with all its intentionally wrongly set fields and layer of
hacks one for each codec on top to get the true value again,
sbr is another "set it wrong and add yet another layer of hacks")
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Observe your enemies, for they first find out your faults. -- Antisthenes
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