[FFmpeg-devel] [PATCH] AAC Encoder, Round 2
Mon Aug 25 15:22:09 CEST 2008
Michael Niedermayer a ?crit :
>>1. Perform some input filtering (lowpass, highpass, stereo attenuation, whatever)
> Its debateable in how far this should be here or seperate and outside of the
While highpass (mainly in order to remove DC) might belong to a general
"preprocessing" step, highpass and stereo attenuation, while being
filtering operations, might/should actually be driven by the encoder
itself (psymodel or encoder core). So even if right now they are using
fixed parameters, it might be a good thing to provide provisions within
the interfaces to set up parameters of those filtering operations per frame.
*stereo attenuation depends of current complexity of input. If the
encoder is easily able to encode the input, there is no point in
performing stereo atenuation.
*lowpassing might increase temporal smearing in case of transcients, so
it might depend on attack detection.
personal page: http://gabriel.mp3-tech.org
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