On Tue, 9 Oct 2018, at 1:57 PM, Tanu Kaskinen wrote: > On Sat, 2018-10-06 at 15:29 -0300, wellington wallace wrote: > > Hi! PulseEffects developer here again. > > > > Like the title says I'd like to know if rewinds can cause crackling noises > > when we are recording from a null sink monitor. > > Yes it can: > https://gitlab.freedesktop.org/pulseaudio/pulseaudio/issues/304 > > > In PulseEffecs I use the > > plugin pulsesrc from GStreamer to record the null sink monitor and whenever > > there is a change in the null sink volume or in the volume of a sink input > > playing to the null sink I can here noises. Looking at Pulseaudio's logs I > > can see lines with: > > > > [null-sink] module-null-sink.c: Requested to rewind 3528 bytes. > > [null-sink] sink.c: Processing rewind... > > [null-sink] sink-input.c: Have to rewind 2840 bytes on render memblockq. > > [null-sink] sink-input.c: Have to rewind 1420 bytes on implementor. > > [null-sink] source.c: Processing rewind... > > [null-sink] module-null-sink.c: Rewound 2840 bytes. > > [pulseaudio] module-stream-restore.c: Storing volume/mute/device for stream > > sink-input-by-media-role:music. > > [pulseaudio] protocol-native.c: Client spotify changes volume of sink input > > Spotify. > > > > whenever the application volume is changed. At the same time they are shown > > I can hear cracklings. So it seems related. I noticed that forcing pulsesrc > > to use lower latencies help but do not fix the problem. Changing volumes > > with pulsesrc latency-time parameter set to 1000 us produces less noises > > than when it is set to 10000 us. > > > > I tried my best to see if there is anything I can do on my side to remove > > this noise I found nothing. Is that how things are or is there anything > > that can be done to remove this noises? > > This is how things are. It would be great if someone would have a hard > look at the monitor source rewinding code and see what goes wrong > there. I'd love it if someone beat me to it, but I think we need some unit testing for this. In general, I've been trying to add some high-level utilities to allow us to write such tests easily, and we need to extend this to do a lot more: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/tree/master/src/tests/lo-test-util.h https://gitlab.freedesktop.org/arun/pulseaudio/blob/reconfigure/src/tests/test-util.h Cheers, Arun _______________________________________________ pulseaudio-discuss mailing list pulseaudio-discuss@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
