demos/demo_waveform_plot.py: improve

diff --git a/python/demos/demo_waveform_plot.py b/python/demos/demo_waveform_plot.py
index 11852a8f293f48421585cd44db3aed6feb68537c..7ab457a3070f55632bc049bb6e685f2be2003964 100755 (executable)
--- a/python/demos/demo_waveform_plot.py
+++ b/python/demos/demo_waveform_plot.py
@@ -9,10 +9,10 @@ def get_waveform_plot(filename, samplerate = 0, ax = None):
     if not ax:
         fig = plt.figure()
         ax = fig.add_subplot(111)
-    hop_s = 512                                        # fft window size
+    hop_s = 4096 # block size
 
     allsamples_max = zeros(0,)
-    downsample = 2  # to plot n samples / hop_s
+    downsample = 2**3  # to plot n samples / hop_s
 
     a = source(filename, samplerate, hop_s)            # source file
     if samplerate == 0: samplerate = a.samplerate
@@ -25,18 +25,27 @@ def get_waveform_plot(filename, samplerate = 0, ax = None):
         allsamples_max = hstack([allsamples_max, new_maxes])
         total_frames += read
         if read < hop_s: break
+    print samples.reshape(hop_s/downsample, downsample).shape
 
     allsamples_max = (allsamples_max > 0) * allsamples_max
     allsamples_max_times = [ ( float (t) / downsample ) * hop_s for t in range(len(allsamples_max)) ]
 
     ax.plot(allsamples_max_times,  allsamples_max, '-b')
     ax.plot(allsamples_max_times, -allsamples_max, '-b')
+    ax.axis(xmin = allsamples_max_times[0], xmax = allsamples_max_times[-1])
 
+    if allsamples_max_times[-1] / float(samplerate) > 60:
+        ax.set_xlabel('time (mm:ss)')
+        ax.set_xticklabels([ "%02d:%02d" % (t/float(samplerate)/60, (t/float(samplerate))%60) for t in ax.get_xticks()[:-1]], rotation = 50)
+    else:
+        ax.set_xlabel('time (ss.mm)')
+        ax.set_xticklabels([ "%02d.%02d" % (t/float(samplerate), 100*((t/float(samplerate))%1) ) for t in ax.get_xticks()[:-1]], rotation = 50)
 if __name__ == '__main__':
+    import matplotlib.pyplot as plt
     if len(sys.argv) < 2:
         print "Usage: %s <filename>" % sys.argv[0]
     else:
         for soundfile in sys.argv[1:]:
             get_waveform_plot(soundfile)
             # display graph
-            show()
+            plt.show()