mirror of
https://github.com/larsimmisch/pyalsaaudio.git
synced 2026-04-16 16:15:31 +00:00
8ea9470454
commit 8abf06be introduced a pause() prior to draining, in an attempt
to work around clearly broken pulseaudio client behavior for capture
streams (drain() is supposed to imply a stop).
but as the workaround was also applied to playback streams, it would
cause nasty "clicks", as the stream would (obviously) stop before being
resumed for draining.
but draining is actually pointless for capture streams, as we're closing
right afterwards, so the samples are lost anyway.
what's more, destructors are not supposed to wait for anything, so
draining in alsapcm_dealloc() was wrong to start with. so we remove it.
note that this is a minor behavior change, which is reflected by the
adjustment of the playback test to have an explicit close() at the end.
finally, close() was also affected by the pulseaudio bug (which was not
addressed before), so there we make draining exclusive to playback
streams.
54 lines
1.4 KiB
Python
Executable File
54 lines
1.4 KiB
Python
Executable File
#!/usr/bin/env python3
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# -*- mode: python; indent-tabs-mode: t; c-basic-offset: 4; tab-width: 4 -*-
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## playbacktest.py
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##
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## This is an example of a simple sound playback script.
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##
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## The script opens an ALSA pcm for sound playback. Set
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## various attributes of the device. It then reads data
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## from stdin and writes it to the device.
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##
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## To test it out do the following:
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## python recordtest.py out.raw # talk to the microphone
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## python playbacktest.py out.raw
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from __future__ import print_function
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import sys
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import time
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import getopt
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import alsaaudio
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def usage():
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print('usage: playbacktest.py [-d <device>] <file>', file=sys.stderr)
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sys.exit(2)
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if __name__ == '__main__':
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device = 'default'
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opts, args = getopt.getopt(sys.argv[1:], 'd:')
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for o, a in opts:
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if o == '-d':
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device = a
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if not args:
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usage()
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f = open(args[0], 'rb')
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# Open the device in playback mode in Mono, 44100 Hz, 16 bit little endian frames
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# The period size controls the internal number of frames per period.
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# The significance of this parameter is documented in the ALSA api.
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out = alsaaudio.PCM(alsaaudio.PCM_PLAYBACK, channels=1, rate=44100, format=alsaaudio.PCM_FORMAT_S16_LE, periodsize=160, device=device)
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# Read data from stdin
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data = f.read(320)
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while data:
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out.write(data)
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data = f.read(320)
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out.close()
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