Setup PCM device in constructor.

Currently, after recording audio using pyalsaaudio, the client is unable to close the device.

The reason is that PulseAudio client tries to drain the pipe to the PulseAudio server (presumably in order to prevent Broken Pipe error) on closing. That will never finish since new data will always arrive in the pipe.

Worse, the __del__ handler was auto-closing and thus auto-hanging.

Therefore, pause before de-allocating.

CHANGES

@@ -1,3 +1,32 @@
+Version 0.8.6:
+- Added four methods to the 'PCM' class to allow users to get detailed information about the device:
+
+  - 'getformats()' returns a dictionary of name / value pairs, one for each of the card's
+    supported formats - e.g. '{"U8": 1, "S16_LE": 2}',
+  - 'getchannels()' returns a list of the supported channel numbers, e.g. '[1, 2]',
+  - 'getrates()' returns supported sample rates for the device, e.g. '[48000]',
+  - 'getratebounds()' returns the device's official minimum and maximum supported 
+    sample rates as a tuple, e.g. '(4000, 48000)'.
+  
+  (#82 contributed by @jdstmporter)
+
+- Prevent hang on close after capturing audio (#80 contributed by @daym)
+
+Version 0.8.5:
+- Return an empty string/bytestring when 'read()' detects an 
+  overrun. Previously the returned data was undefined (contributed by @jcea)
+
+- Unlimited setperiod buffer size when reading frames (contributed by @jcea)
+
+Version 0.8.4:
+- Fix Python3 API usage broken in 0.8.3
+
+Version 0.8.3:
+- Add DSD sample formats (contributed by @lintweaker)
+- Add Mixer.handleevents() to acknowledge events identified by select.poll (contributed by @PaulSD)
+- Add functions for listing cards and their names (contributed by @chrisdiamand)
+- Add a method for setting enums (contributed by @chrisdiamand)
+
 Version 0.8.2:
 - fix #3 (we cannot get the revision from git for pip installs)
 

doc/libalsaaudio.rst

@@ -443,35 +443,31 @@ Mixer objects have the following methods:
    This method will fail if the mixer has no capture switch capabilities.
 
 
-.. method:: Mixer.getvolume(direction=PCM_PLAYBACK, unit=Percent)
+.. method:: Mixer.getvolume([direction])
 
    Returns a list with the current volume settings for each channel. The list
-   elements are percentages or dB values, depending on *unit*.
+   elements are integer percentages.
 
-   The *direction* argument can be either :const:`PCM_PLAYBACK` or
+   The optional *direction* argument can be either :const:`PCM_PLAYBACK` or
    :const:`PCM_CAPTURE`, which is relevant if the mixer can control both
    playback and capture volume. The default value is :const:`PCM_PLAYBACK`
    if the mixer has playback channels, otherwise it is :const:`PCM_CAPTURE`.
 
 
-.. method:: Mixer.setvolume(volume, channel=MIXER_CHANNEL_ALL, direction=PCM_PLAYBACK, unit=Percent)
+.. method:: Mixer.setvolume(volume, [channel], [direction])
 
    Change the current volume settings for this mixer. The *volume* argument
-   controls the new volume setting as either a percentage or a dB value. Both
+   controls the new volume setting as an integer percentage.
-   integer and floating point values can be given.
 
-   The *channel* argument can be used to restrict the channels for which the volume is
+   If the optional argument *channel* is present, the volume is set
-   set. By default, the volume of all channels is adjusted. This assumes that the mixer
+   only for this channel. This assumes that the mixer can control the
-   can control the volume for the channels independently.
+   volume for the channels independently.
 
-   The *direction* argument can be either :const:`PCM_PLAYBACK` or
+   The optional *direction* argument can be either :const:`PCM_PLAYBACK` or
    :const:`PCM_CAPTURE`, which is relevant if the mixer can control both
    playback and capture volume. The default value is :const:`PCM_PLAYBACK`
    if the mixer has playback channels, otherwise it is :const:`PCM_CAPTURE`.
 
-   The *unit* argument determines how the volume value is interpreted, as a prcentage
-   or as a dB value.
-   
 .. method:: Mixer.setmute(mute, [channel])
 
    Sets the mute flag to a new value. The *mute* argument is either 0 for not

doc/pyalsaaudio.rst

@@ -75,7 +75,7 @@ development at the time - and neither are very feature complete.
 I wrote PyAlsaAudio to fill this gap. My long term goal is to have the module
 included in the standard Python library, but that looks currently unlikely.
 
-PyAlsaAudio hass full support for sound capture, playback of sound, as well as
+PyAlsaAudio has full support for sound capture, playback of sound, as well as
 the ALSA Mixer API.
 
 MIDI support is not available, and since I don't own any MIDI hardware, it's

mixertest.py

@@ -46,17 +46,13 @@ def show_mixer(name, kwargs):
     print("Capabilities: %s %s" % (' '.join(mixer.volumecap()),
                                    ' '.join(mixer.switchcap())))
     volumes = mixer.getvolume()
-    for i, v in enumerate(volumes):
+    for i in range(len(volumes)):
-        print("Channel %i volume: %.02f%%" % (i, v))
+        print("Channel %i volume: %i%%" % (i,volumes[i]))
-
+        
-    volumes = mixer.getvolume(unit=alsaaudio.dB)
-    for i, v in enumerate(volumes):
-        print("Channel %i volume: %.02fdB" % (i, v))
-
     try:
         mutes = mixer.getmute()
-        for i, m in enumerate(mutes):
+        for i in range(len(mutes)):
-            if m:
+            if mutes[i]:
                 print("Channel %i is muted" % i)
     except alsaaudio.ALSAAudioError:
         # May not support muting
@@ -64,8 +60,8 @@ def show_mixer(name, kwargs):
 
     try:
         recs = mixer.getrec()
-        for i, r in enumerate(recs):
+        for i in range(len(recs)):
-            if r:
+            if recs[i]:
                 print("Channel %i is recording" % i)
     except alsaaudio.ALSAAudioError:
         # May not support recording

playwav.py

@@ -30,7 +30,7 @@ def play(device, f):
     else:
         raise ValueError('Unsupported format')
 
-    periodsize = f.getframerate() / 8
+    periodsize = f.getframerate() // 8
 
     device.setperiodsize(periodsize)
     

setup.py

@@ -8,7 +8,7 @@ from setuptools import setup
 from setuptools.extension import Extension
 from sys import version
 
-pyalsa_version = '0.8.4'
+pyalsa_version = '0.8.6'
 
 if __name__ == '__main__':
     setup(