Use .stats attribute in examples and other example updates

Author: mgeier

examples/bleeperoo.py

@@ -1,4 +1,15 @@
 #!/usr/bin/env python3
+"""Play some random bleeps.
+
+This example shows the feature of playing a buffer at a given absolute time.
+Since all play_buffer() invocations are (deliberately) done at once, this puts
+some strain on the "action queue".
+The "qsize" has to be increased in order to handle this.
+
+This example also shows that NumPy arrays can be used, as long as they are
+C-contiguous and use the 'float32' data type.
+
+"""
 
 from __future__ import division  # Only needed for Python 2.x
 import numpy as np
@@ -13,6 +24,7 @@
 samplerate = 44100
 
 bleeps = 300
+qsize = 512  # Must be a power of 2
 
 attack = 0.005
 release = 0.1
@@ -58,12 +70,13 @@
     bleeplist.append(bleep)
 
 with rtmixer.Mixer(device=device, channels=channels, blocksize=blocksize,
-                   samplerate=samplerate, latency=latency, qsize=512) as m:
+                   samplerate=samplerate, latency=latency, qsize=qsize) as m:
     start_time = m.time
     for bleep in bleeplist:
         m.play_buffer(bleep,
                       channels=[r.randint(channels) + 1],
                       start=start_time + r.uniform(start_min, start_max))
     while m.actions:
         sd.sleep(100)
-    # TODO: check for xruns
+print('{0} buffer underflows in {1} processed audio blocks'.format(
+    m.stats.output_underflows, m.stats.blocks))

examples/delay.py

@@ -27,4 +27,6 @@
     print('press Return to quit')
     print('#' * 80)
     input()
-# TODO: check xruns
+print('input underflows:', stream.stats.input_underflows)
+print('input overflows:', stream.stats.input_overflows)
+print('output underflows:', stream.stats.output_underflows)

examples/play_file.py

@@ -38,4 +38,6 @@
             if written < size:
                 break
         m.wait(action)
-        # TODO: check for xruns and ringbuffer errors
+        # TODO: check for ringbuffer errors
+        if action.stats.output_underflows:
+            print('output underflows:', action.stats.output_underflows)

examples/plot_input.py

@@ -76,4 +76,5 @@ def update_plot(frame):
     q = rtmixer.RingBuffer(elementsize, stepsize * qsize)
     action = stream.record_ringbuffer(q)
     plt.show()
+# TODO: check for ringbuffer errors?
 print('Input overflows:', action.stats.input_overflows)