[FFmpeg-devel] [PATCH 1/5] libavcodec: Implementation of 32 bit fixed point FFT

Michael Niedermayer michaelni at gmx.at
Sat Jun 22 14:33:25 CEST 2013

On Fri, Jun 21, 2013 at 02:09:52PM +0000, Zeljko Lukac wrote:
> Rockboxs fft is 10% faster, but this is due to lower accuracy of multiplication (with each multiplication they loose 1 bit of accuracy compared to our implementation). If both ffts use the same multiplication routines then our fft is 3-4% faster (measured on PC and MIPS platform). This holds for plain C versions of both ffts. We expect that increased accuracy can be achieved without speed penalty when assembly optimizations are applied.

The rockbox FFT is said to have >16bit accuracy
have you checked the output accuracy from the decoder with both FFTs?


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