[CELT-dev] Variable frame size and API changes
Jean-Marc.Valin at USherbrooke.ca
Wed May 19 08:07:14 PDT 2010
Quoting Bob Bang <bob.bang2 at gmail.com>:
> in regards to your oversampling idea, the extra processing required may
> nullify the gains from using DSPLIB over kissfft.
I'm not suggesting resampling, but actually doing the native sampling at 51.2
> To be honest, I have not measured the MIPS difference between DSPLIB and
> kiss FFT, I will try to do that sometime soon to see how much of a
> difference the intrinsic libraries make. Do you have those numbers already?
> 2010/5/18 Jean-Marc Valin <Jean-Marc.Valin at usherbrooke.ca>
> > Hi Bob,
> > A few questions/comments:
> > 1) It may be possible to use the TI DSP for all of the radix-2 steps in the
> > FFT
> > and then only apply the radix 3 and 5 in C.
> > 2) I assume that the sampling is done on the TI chip, so couldn't you just
> > configure it to work at 51.2 kHz? This would produce frames that are powers
> > of
> > two and the resulting bit-stream would be perfectly compatible with a
> > decoder
> > running with the same frame duration (hence 15/16 the actual number of
> > samples)
> > at 48 kHz.
> > Cheers,
> > Jean-Marc
> > Quoting Bob Bang <bob.bang2 at gmail.com>:
> > > Hello Jean-Marc, I appreciate you taking our feedback in this change.
> > >
> > > I would be against this new input frame size change as I am developing on
> > > the TI 55x platform. On this platform it benefits to use the DSPLIB
> > which
> > > REQUIRES a power of 2 frame size.
> > >
> > > My current setup is using a 48kHz sample rate and a 128 sample frame size
> > > (~2.5ms).
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