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comparison service/audioInputLevels/audioInputLevelsPulse.py @ 82:d288bc1174d4

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audio input levels to graphite Ignore-this: b1422609f3bf51778b8b2284ca914916
author drewp@bigasterisk.com
date Fri, 02 Aug 2013 07:55:45 -0700
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children f84129fbbe38
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81:ef639d892e77 82:d288bc1174d4
1 # based on http://freshfoo.com/blog/pulseaudio_monitoring
2 from __future__ import division
3 import socket, argparse
4 from Queue import Queue
5 from ctypes import POINTER, c_ubyte, c_void_p, c_ulong, cast
6 import galena
7
8 # From https://github.com/Valodim/python-pulseaudio
9 from pulseaudio import lib_pulseaudio as P
10
11 METER_RATE = 1
12 MAX_SAMPLE_VALUE = 127
13
14 class PeakMonitor(object):
15
16 def __init__(self, source_name, rate):
17 self.source_name = source_name
18 self.rate = rate
19
20 # Wrap callback methods in appropriate ctypefunc instances so
21 # that the Pulseaudio C API can call them
22 self._context_notify_cb = P.pa_context_notify_cb_t(self.context_notify_cb)
23 self._source_info_cb = P.pa_source_info_cb_t(self.source_info_cb)
24 self._stream_read_cb = P.pa_stream_request_cb_t(self.stream_read_cb)
25
26 # stream_read_cb() puts peak samples into this Queue instance
27 self._samples = Queue()
28
29 # Create the mainloop thread and set our context_notify_cb
30 # method to be called when there's updates relating to the
31 # connection to Pulseaudio
32 _mainloop = P.pa_threaded_mainloop_new()
33 _mainloop_api = P.pa_threaded_mainloop_get_api(_mainloop)
34 context = P.pa_context_new(_mainloop_api, 'peak_demo')
35 P.pa_context_set_state_callback(context, self._context_notify_cb, None)
36 P.pa_context_connect(context, None, 0, None)
37 P.pa_threaded_mainloop_start(_mainloop)
38
39 def __iter__(self):
40 while True:
41 yield self._samples.get()
42
43 def context_notify_cb(self, context, _):
44 state = P.pa_context_get_state(context)
45
46 if state == P.PA_CONTEXT_READY:
47 print "Pulseaudio connection ready..."
48 # Connected to Pulseaudio. Now request that source_info_cb
49 # be called with information about the available sources.
50 o = P.pa_context_get_source_info_list(context, self._source_info_cb, None)
51 P.pa_operation_unref(o)
52
53 elif state == P.PA_CONTEXT_FAILED :
54 print "Connection failed"
55
56 elif state == P.PA_CONTEXT_TERMINATED:
57 print "Connection terminated"
58
59 def source_info_cb(self, context, source_info_p, _, __):
60 if not source_info_p:
61 return
62
63 source_info = source_info_p.contents
64
65 if source_info.name == self.source_name:
66 # Found the source we want to monitor for peak levels.
67 # Tell PA to call stream_read_cb with peak samples.
68 print 'setting up peak recording using', source_info.name
69 print 'description:', source_info.description
70 samplespec = P.pa_sample_spec()
71 samplespec.channels = 1
72 samplespec.format = P.PA_SAMPLE_U8
73 samplespec.rate = self.rate
74
75 pa_stream = P.pa_stream_new(context, "peak detect demo", samplespec, None)
76 P.pa_stream_set_read_callback(pa_stream,
77 self._stream_read_cb,
78 source_info.index)
79 P.pa_stream_connect_record(pa_stream,
80 source_info.name,
81 None,
82 P.PA_STREAM_PEAK_DETECT)
83
84 def stream_read_cb(self, stream, length, index_incr):
85 data = c_void_p()
86 P.pa_stream_peek(stream, data, c_ulong(length))
87 data = cast(data, POINTER(c_ubyte))
88 for i in xrange(length):
89 # When PA_SAMPLE_U8 is used, samples values range from 128
90 # to 255 because the underlying audio data is signed but
91 # it doesn't make sense to return signed peaks.
92 self._samples.put(data[i] - 128)
93 P.pa_stream_drop(stream)
94
95 def main():
96
97
98 parser = argparse.ArgumentParser()
99 parser.add_argument(
100 '--source', required=True,
101 help='pulseaudio source name (use `pactl list sources | grep Name`)')
102
103 args = parser.parse_args()
104
105
106 out = galena.Galena(host='bang')
107 prefix = 'system.house.audio.%s' % socket.gethostname()
108 monitor = PeakMonitor(args.source, METER_RATE)
109 for sample in monitor:
110 #print ' %3d %s' % (sample, '>' * sample)
111 out.send(prefix + ".max", sample / 128)
112
113 if __name__ == '__main__':
114 main()