[FFmpeg-devel] [RFC] Generic psychoacoustic model interface

Måns Rullgård mans
Wed Aug 27 14:21:38 CEST 2008


Alexander E. Patrakov wrote:
> Kostya wrote:
>> Here's my first attempt to define codec-agnostic psy model.
>> Here's an interface for it. I'm not sure about AC3, but
>> it should be possible to use it with DCA, Vorbis,
>> MPEG Audio Layers I-III and NBC, maybe WMA too.
>> In case somebody codes an implementation, of course.
>> Personally I plan to make my encoder use it backed with
>> already implemented 3GPP model.
>
> 1) The general issue of using _any_ psychoacoustical model with HD (>48 kHz)
> audio. How is the whole spectrum supposed to be split into bands? I.e., with
> 192 kHz sampling rate (think DCA with proprietary extensions), are you really
> sure to split the whole 96 kHz spectrum into just 128 equal subbands?

Lowpass filter with a cutoff of 30-40 kHz.  Nobody will be able to tell
the difference.

-- 
M?ns Rullg?rd
mans at mansr.com




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