On 15.06.2015 05:54, Nick wrote: > On 06/14/2015 12:03 PM, Georg Chini wrote: >> On 14.06.2015 18:54, Nick wrote: >>> Greetings PulseAudio folks: >>> >>> I'm trying to pipe audio between an amateur radio (basically a USB sound >>> card) hooked to a Raspberry Pi and my laptop over a local network. I've >>> built PulseAudio 6 on a Raspberry Pi B+ and set up module-tunnel-sink >>> and module-tunnel-source, and that's all functioning. I can record audio >>> on my laptop and it seems to work well. However, I need to be able to >>> monitor the sounds coming out of the radio live, so I set up a >>> module-loopback with the source set to the USB sound card on the RPi. >>> >>> Here are the relevant bits in my system.pa config file: >>> >>> load-module module-tunnel-sink server=laptop sink_name=xps rate=11025 >>> load-module module-tunnel-source server=laptop source_name=xpss >>> rate=11025 >>> load-module module-loopback >>> source=TI_USB_Audio_CODEC-00-CODEC.analog-stereo latency_msec=100 >>> rate=11025 >>> >>> I've downsampled because I'm trying to minimize bandwidth and don't need >>> hi-fi audio (after all, it's a ham radio). This works, but only for a >>> few minutes. Then, the audio from the loopback becomes choppy and >>> eventually fades out completely. It sits silently for about a minute >>> (sometimes more) and then comes back in full quality. A minute or so >>> later, the process repeats. >>> >>> Some interesting tidbits: >>> 1) Only the loopback fades. If I'm recording in an application on the >>> laptop from the networked tunnel source directly, it holds the signal >>> nicely the whole time (even during the fadeouts). >>> 2) If I connect to my local network over a VPN, the loopback fading does >>> not occur at all. >>> 3) The fading happens both on wifi connections and on hard-wired ones. >>> 4) If I change the target of the loopback in pavucontrol's Playback tab >>> to something else and then back to my laptop speakers, it often stops a >>> fadeout and comes back strong for a minute or so (and then fades out >>> again). >>> 5) The fading occurs both with the downsampled rate set on the loopback >>> and with the default. >>> 6) This happens on multiple remix methods, including the default and >>> trivial. >>> 7) This happens on both the Raspberry Pi B+ and on the Raspberry Pi 2. >>> CPU on the RPi2 is at about 20%. >>> 8) The client (my laptop) has PulseAudio 4.0, not 6.0 like the server. >>> >>> I've uploaded a recording of the fading phenomenon that you can listen >>> to here: http://partofthething.com/upload/pulseaudio-fadeout.mp3 >>> >>> I'm not sure what to do to continue debugging. Any suggestions? >>> >>> Best regards, >>> -Nick >>> >> Hello Nick, >> >> can you send some debug output from your pulseaudio session? It >> might help to identify the problem. module-loopback should provide >> a state update each adjust_time. >> > > I: [pulseaudio] module-tunnel.c: Server signalled buffer overrun/underrun. > D: [pulseaudio] module-tunnel.c: Server reports playback started. > I: [pulseaudio] module-tunnel.c: Server signalled buffer overrun/underrun. > D: [pulseaudio] module-tunnel.c: Server reports playback started. > I: [pulseaudio] module-tunnel.c: Server signalled buffer overrun/underrun. > D: [pulseaudio] module-tunnel.c: Server reports playback started. > D: [pulseaudio] module-loopback.c: Loopback overall latency is 218.50 ms > + 254.51 ms + 0.40 ms = 473.41 ms > D: [pulseaudio] module-loopback.c: Should buffer 0 bytes, buffered at > minimum 808 bytes > D: [pulseaudio] module-loopback.c: [xps] Updated sampling rate to 11045 Hz. > > Let me know if there's more info that might help. Many thanks! > Best, > -Nick > The lines coming from module-loopback look OK. It might be an issue with module-loopback changing the sample rate of the sink-input. Can you try and run it with adjust_time=0 to avoid latency adjustments? Do you get the messages from the tunnel sink also when you are only recording? Did you test out module-tunnel-sink-new if it makes a difference? Regards Georg
