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. > Georg: Yes. I ran with -vvvv and am copying things from the log that I think might be relevant. First, we have some info about resampling: D: [pulseaudio] module-loopback.c: Loopback overall latency is 167.47 ms + 78.09 ms + 0.78 ms = 246.35 ms D: [pulseaudio] module-loopback.c: Should buffer 0 bytes, buffered at minimum 1412 bytes I: [pulseaudio] module-loopback.c: New rate of 11060 Hz not within 2â?° of 11025 Hz, forcing smaller adjustment D: [pulseaudio] module-loopback.c: [xps] Updated sampling rate to 11047 Hz. D: [pulseaudio] module-loopback.c: Loopback overall latency is 153.18 ms + 67.98 ms + 0.38 ms = 221.55 ms D: [pulseaudio] module-loopback.c: Should buffer 0 bytes, buffered at minimum 1100 bytes D: [pulseaudio] module-loopback.c: [xps] Updated sampling rate to 11052 Hz. D: [pulseaudio] module-loopback.c: Loopback overall latency is 138.84 ms + 56.82 ms + 0.15 ms = 195.82 ms D: [pulseaudio] module-loopback.c: Should buffer 0 bytes, buffered at minimum 44 bytes Then, an error: E: [alsa-source-USB Audio] alsa-source.c: ALSA woke us up to read new data from the device, but there was actually nothing to read! E: [alsa-source-USB Audio] alsa-source.c: Most likely this is a bug in the ALSA driver 'snd_usb_audio'. Please report this issue to the ALSA developers. E: [alsa-source-USB Audio] alsa-source.c: We were woken up with POLLIN set -- however a subsequent snd_pcm_avail() returned 0 or another value < min_avail. D: [pulseaudio] module-loopback.c: Loopback overall latency is 163.10 ms + 25.39 ms + 0.38 ms = 188.87 ms D: [pulseaudio] module-loopback.c: Should buffer 0 bytes, buffered at minimum 0 bytes Then, more resampling messages followed by some buffer issues: D: [pulseaudio] module-loopback.c: [xps] Updated sampling rate to 11025 Hz. 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 4.64 ms + 439.09 ms + 0.92 ms = 444.65 ms D: [pulseaudio] module-loopback.c: Should buffer 0 bytes, buffered at minimum 0 bytes D: [pulseaudio] module-loopback.c: [xps] Updated sampling rate to 11025 Hz. 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 272.80 ms + 434.29 ms + 0.42 ms = 707.51 ms D: [pulseaudio] module-loopback.c: Should buffer 0 bytes, buffered at minimum 10540 bytes I: [pulseaudio] module-loopback.c: New rate of 11288 Hz not within 2â?° of 11025 Hz, forcing smaller adjustment D: [pulseaudio] module-loopback.c: [xps] Updated sampling rate to 11047 Hz. D: [pulseaudio] module-loopback.c: Loopback overall latency is 387.70 ms + 388.88 ms + 0.75 ms = 777.33 ms As the fading ended, I think these messages were being printed: D: [pulseaudio] module-loopback.c: [xps] Updated sampling rate to 11025 Hz. 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 27.98 ms + 67.21 ms + 0.46 ms = 95.66 ms D: [pulseaudio] module-loopback.c: Should buffer 0 bytes, buffered at minimum 0 bytes D: [pulseaudio] module-loopback.c: [xps] Updated sampling rate to 11025 Hz. 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 > Regards > Georg >
