[FFmpeg-devel] [PATCH] swresample: add exact_rational option

Muhammad Faiz mfcc64 at gmail.com
Mon Jun 13 02:46:22 CEST 2016


On Mon, Jun 13, 2016 at 2:19 AM, Michael Niedermayer
<michael at niedermayer.cc> wrote:
> On Sun, Jun 12, 2016 at 07:56:31AM +0700, Muhammad Faiz wrote:
>> give high quality resampling
>> as good as with linear_interp=on
>> as fast as without linear_interp=on
>> tested visually with ffplay
>> ffplay -f lavfi "aevalsrc='sin(10000*t*t)', aresample=osr=48000,
>> showcqt=gamma=5"
>> ffplay -f lavfi "aevalsrc='sin(10000*t*t)',
>> aresample=osr=48000:linear_interp=on, showcqt=gamma=5"
>> ffplay -f lavfi "aevalsrc='sin(10000*t*t)',
>> aresample=osr=48000:exact_rational=on, showcqt=gamma=5"
>>
>> slightly speed improvement
>> for fair comparison with -cpuflags 0
>> audio.wav is ~ 1 hour 44100 stereo 16bit wav file
>> ffmpeg -i audio.wav -af aresample=osr=48000 -f null -
>>         old         new
>> real    13.498s     13.121s
>> user    13.364s     12.987s
>> sys      0.131s      0.129s
>>
>> linear_interp=on
>>         old         new
>> real    23.035s     23.050s
>> user    22.907s     22.917s
>> sys      0.119s     0.125s
>>
>> exact_rational=on
>> real    12.418s
>> user    12.298s
>> sys      0.114s
>>
>> possibility to decrease memory usage if soft compensation is ignored
>
> interresting
>
> can you add some fate tests ?
> (that way this also could be easily tested for platform specific bugs)
>
patch attached

thanks
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