2012/5/17 cee1 <fykcee1 at gmail.com>: > 2012/5/12 cee1 <fykcee1 at gmail.com>: >> Hi all, >> >> We're using PA on our product, and sometimes audio playback may >> corrupt after adjusting volume. >> >> We found a way to (relatively) easily reproduce the problem: >> 1. Play sample.mp3 through totem in repeat mode. >> 2. In gnome-volume-control, Hardware tap, repeat to shift between "Off >> profile" and "Analog Stereo Duplex profile". >> >> When the problem happens, the corruption continues until I: >> * Do one more shift between "Off profile" and "Analog Stereo Duplex profile". >> * Close totem (close all PA playback clients). >> * Adjust volume. >> >> When the problem happens, open another PA client doing audio playback, >> is also corrupt. >> >> Some additional information: >> * Output of alsa-info.sh on our product: >> http://dev.lemote.com/files/upload/software/PA-apc/alsa-info-lemote >> * PA daemon log: >> http://dev.lemote.com/files/upload/software/PA-apc/pulseaudio.log >> * The corrupted sound: >> http://dev.lemote.com/files/upload/software/PA-apc/corrupted_sound.ogg >> * The sample mp3: http://dev.lemote.com/files/upload/software/PA-apc/sample.mp3 > When the problem happens today, I notice: > 1) PA complains "alsa-source.c: Overrun!". I doesn't run any recording > ?application then. Curious. > 2) Playback becomes good automatically when play sample.mp3 again(note > totem is in repeat playing mode). It says sink becomes idle(I didn't > touch totem, so totem should keep playing back). Update: We've found a way the can reproduce the problem more quickly on our product: 1. do audio playback 2. alsamixer, select 'Master', press 'm' and hold for a while. Then release 'm', playback corrupts(sounds similar to http://dev.lemote.com/files/upload/software/PA-apc/corrupted_sound.ogg). I notice the following in PA daemon log: ( 439.779| 55.236) D: [alsa-sink][modules/alsa/alsa-sink.c:1261 sink_get_volume_cb()] Read hardware volume: 0: 78% 1: 78% ([0x31a4e488]) ( 439.780| 0.000) D: [alsa-sink][modules/alsa/alsa-sink.c:1266 sink_get_volume_cb()] in dB: 0: -6.40 dB 1: -6.40 dB ([0x31a4e488]) ( 439.781| 0.001) I: [pulseaudio][modules/module-device-restore.c:723 subscribe_callback()] Storing volume/mute for device+port sink:alsa_output.pci-0000_00_14.2.analog-stereo:analog-output. ([0x7f891270]) ( 439.782| 0.001) D: [alsa-sink][modules/alsa/alsa-sink.c:1607 process_rewind()] Requested to rewind 65536 bytes. ([0x31a4e9d8]) ( 439.782| 0.000) D: [alsa-sink][modules/alsa/alsa-sink.c:1630 process_rewind()] Limited to 11248 bytes. ([0x31a4e9d8]) ( 439.783| 0.000) D: [alsa-sink][modules/alsa/alsa-sink.c:1633 process_rewind()] before: 2812 ([0x31a4e9d8]) ( 439.783| 0.000) D: [alsa-sink][modules/alsa/alsa-sink.c:1641 process_rewind()] after: 2812 ([0x31a4e9d8]) ( 439.783| 0.000) D: [alsa-sink][modules/alsa/alsa-sink.c:1649 process_rewind()] Rewound 11248 bytes. ([0x31a4e9d8]) ( 439.783| 0.000) D: [alsa-sink][pulsecore/sink.c:935 pa_sink_process_rewind()] Processing rewind... ([0x31a4e998]) ( 439.783| 0.000) D: [alsa-sink][pulsecore/sink.c:3617 pa_sink_volume_change_rewind()] latency = 632 ([0x31a4e928]) ( 439.784| 0.000) D: [alsa-sink][pulsecore/sink-input.c:984 pa_sink_input_process_rewind()] Have to rewind 11248 bytes on render memblockq. ([0x31a4e940]) ( 439.784| 0.000) D: [alsa-sink][pulsecore/source.c:864 pa_source_process_rewind()] Processing rewind... ([0x31a4e958]) I guess it is 'rewind' that cause the problem? What does rewind do? Why we need rewind here? BTW, PA has module-device-restore and module-stream-restore, dose that means we don't need alsa-restore.service/store stuffs? What is the difference between device-restore and stream-restore? ---- Regards, cee1
