[pulseaudio-tickets] [PulseAudio] #54: sox output to ALSA pulse device hangs

[PulseAudio]

#54: sox output to ALSA pulse device hangs
----------------------------+-----------------------------------------------
 Reporter:  ZlatkO          |       Owner:  lennart
     Type:  defect          |      Status:  new    
 Priority:  normal          |   Milestone:         
Component:  module-alsa-*   |    Severity:  normal 
 Keywords:  sox ALSA hangs  |  
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 While sox works fine with both OSS/padsp ('padsp sox -t wav some.wav -t
 ossdsp /dev/dsp') and "real" ALSA devices ('sox -t wav some.wav -t alsa
 hw:0'), ALSA output to pulse doesn't work at all ('sox -t wav some.wav -t
 alsa pulse'). In the latter case, sox just hangs, hogs the CPU, and can't
 be terminated with Ctrl-C. The only way to get rid of it is to 'kill
 -KILL' it from another terminal.

 This affects, for example, audio preview in Nautilus. Audio preview is
 effectively done by piping the audio file to be previewed to 'play',
 which, in turn, is a wrapper for sox. Do this for a few times, and you'll
 be left with a bunch of rogue sox processes hogging the CPU, and no audio
 preview.

 I'll also file bug reports with ALSA and sox, just to be on the safe side.
 Somehow I don't suspect sox itself to be the culprit, though, because it
 works fine whenever only either one of ALSA or !PulseAudio is involved
 (OSS + padsp, ALSA + any other device than pulse), but breaks when both
 are (ALSA + pulse device).

 PS: I temporarily fixed the problem myself by simply patching 'play' (the
 sox wrapper), I'll attach the patch here just in case someone else gets
 bitten by the same bug.

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Ticket URL: <http://pulseaudio.org/ticket/54>
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