[FFmpeg-devel] [PATCH 0/4] fftw exploration (WIP)

[Ganesh Ajjanagadde]

On Fri, Mar 25, 2016 at 9:36 AM, Nicolas George <george at nsup.org> wrote:
> Le sextidi 6 germinal, an CCXXIV, Ganesh Ajjanagadde a écrit :
>> Depends on if it is small or not. Yes, in many codecs, FFT's are short
>> length ones, e.g 512. However, on long lengths, e.g 8192+, as seen
>> from the benches, there are sometimes 2x variations at the moment.
>
> And how much of the actual total decoding is spent in the FFT? Even a ×50
> speedup would be useless if it is for a function that never amounts to more
> than 0,01% of the actual time. The FFT is probably not that negligible, but
> this is not a ×50 speedup either, and I have no idea how frequent are long
> lengths.

Paul had some interest in 2^17 fft's at a point.

>
> You often do your benchmark like that, please try to be more careful and
> benchmark spans of code that are actually relevant for FFmpeg's tasks.

Will keep in mind, thanks.

>
> Regards,
>
> --
>   Nicolas George
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>