16.10.2014 11:48, Alexander E. Patrakov wrote: > FFMpeg code indeed looks cleaner and supports more sample formats > instead of insisting on s16. However, if one inlines the > resample_one() function from libavresample/resample_template.c into > the if (!nearest_neighbour) branch of resample() from > libavresample/resample.c, he will get almost exactly what we already > have in PulseAudio's embedded copy of the ffmpeg resampler. So, all > the speed benefits (if any) come from changing the working sample > format and from ffmpeg build system that applies optimizations via > CFLAGS that are sensible for this kind of code. Sorry, I have to correct myself here. One more possible reason for speed difference would be that PulseAudio's copy repeatedly tests c->linear (which is BTW always false), while, instead of that, FFMpeg's copy calls a function through a pointer in order to distinguish between situations where linear interpolation between filter taps is needed or unneeded. -- Alexander E. Patrakov
