On 18.12.2015 08:45, Alexander E. Patrakov wrote: > 18.12.2015 11:47, Georg Chini wrote: >> On 18.12.2015 06:49, Tanu Kaskinen wrote: >>> >>> >>> Making pa_sample_rate_valid() accept values above PA_RATE_MAX isn't >>> very nice, but I can see how it's better than the current behaviour, >>> which probably can cause the daemon to crash. Alexander mentioned in >>> IRC that he'd prefer doing the adaptive resampling inside module- >>> loopback rather than using pa_sink_input_set_rate(), and this change >>> demonstrates one good reason for that. I'm not asking you to implement >>> that change, but it certainly would be nice. >>> >>> -- >>> Tanu >> Yes, doing it inside the module would really be a good idea. The >> main issue my controller is fighting against are the systematic >> errors introduced by changing the rate of the sink input. When >> you change the rate, the next latency report has an extremely >> high error. >> Can you point me to some code that implements resampling >> so that I have an example of what to do? > > Look at the ffmpeg resampler inside PulseAudio tree, it's the simplest > possible one. But I'd say that it's pointless to look at the code > without understanding the math behind all of that, so please look at > these links, too: > > https://en.wikipedia.org/wiki/Sinc_filter > https://ccrma.stanford.edu/~jos/resample/resample.pdf > I would first use the existing resamplers before trying to implement my own. So I was rather referring to the framework used in pulseaudio when using existing resamplers. If I ever write a specific resampler for the loopback module it could be integrated into the normal framework.
