[FFmpeg-devel] [PATCH] NEON FFT/IMDCT

Naotoshi Nojiri naonoj
Tue Sep 8 07:35:59 CEST 2009


Hi,

Thank you for all of your comments and advices. I revised the patch
The latest performance is as follows.

FFT (fft-test -s):
32.0us
IMDCT (fft-test -i -m -s):
11.3us


Mans,

I also wrote a pure-asm version of MDCT, but because it doesn't
improve the performance, please ignore the part and use the FFT part
only.

Thanks,
Naotoshi Nojiri


2009/9/8 M?ns Rullg?rd <mans at mansr.com>:
> M?ns Rullg?rd <mans at mansr.com> writes:
>
>> Naotoshi Nojiri <naonoj at gmail.com> writes:
>>
>>> Hi,
>>>
>>> I tested the patch on Cortex-A8 @500MHz (BeagleBoard).
>>> FFT (fft-test -s):
>>> 440.8 -> 34.2 us/transform (12.9x speed up)
>>> IMDCT (fft-test -i -m -s):
>>> 142.4 -> 11.8 us/transform (12.1x speed up)
>>>
>>> I had written NEON intrinsics code a bit, but this is my first
>>> ARM/NEON code in assembly.
>>> So, any comments and suggestions would be appreciated.
>>
>> Inline asm is unacceptable.
>
> I have a faster, pure-asm version of the mdct stuff almost ready. ?No
> need to resubmit.
>
> --
> M?ns Rullg?rd
> mans at mansr.com
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at mplayerhq.hu
> https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
>
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