[FFmpeg-devel] [PATCH] HE-AAC v1 decoder try 4

Vladimir Pantelic pan
Wed Feb 17 09:44:24 CET 2010

Alexander Strange wrote:
> On Feb 16, 2010, at 6:19 PM, Alex Converse 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 :)
>>  <sbr.diff>
> I tried it with ffplay and it plays 2x too slow. If ffplay needs to be fixed, I wonder if other players will too? Well, it's unavoidable anyway.
> ffmpeg to wav sounds fine.

guess its the issue that the container signals the smaller (non-sbr) sample rate, e.g. 24khz and the decoder applies SBR 
and returns 48kHz. I had to fix my player to switch to the decoder returned sample rate too...

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