[FFmpeg-devel] ac3 imdct question

Benjamin Larsson banan
Mon Oct 13 17:47:54 CEST 2008

Arpi wrote:
> Hi,
> Could someone DSP guru please explain me, what ff_fft_calc exactly
> calculates in ff_imdct_half_c() of mdct.c ?

Do I miss something obvious, ff_fft_calc should calculate the fft of a 
complex buffer of floats.

> I've tried to replace it (for experimenting with pitch correction...)
> with the 'standard' inverse discrete fourier transform but it does
> not work, the sound (ac3 music sample file) gets heavily distorted :(
> here's my modification:

Replacing the fft with a dct will not work.

Benjamin Larsson

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