demos/demo_onset.py: add simple onset example, update demo_onset_plot.py

diff --git a/python/demos/demo_onset.py b/python/demos/demo_onset.py
new file mode 100755 (executable)
index 0000000..20e7bf0
--- /dev/null
+++ b/python/demos/demo_onset.py
@@ -0,0 +1,37 @@
+#! /usr/bin/env python
+
+import sys
+from aubio import onset, source
+from numpy import array, hstack, zeros
+
+win_s = 512                 # fft size
+hop_s = win_s / 2           # hop size
+
+if len(sys.argv) < 2:
+    print "Usage: %s <filename> [samplerate]" % sys.argv[0]
+    sys.exit(1)
+
+filename = sys.argv[1]
+
+samplerate = 0
+if len( sys.argv ) > 2: samplerate = int(sys.argv[2])
+
+s = source(filename, samplerate, hop_s)
+samplerate = s.samplerate
+o = onset("default", win_s, hop_s)
+
+# onset detection delay, in blocks
+delay = 4. * hop_s
+
+onsets = []
+total_frames = 0
+while True:
+    samples, read = s()
+    is_onset = o(samples)
+    if is_onset:
+        this_onset = int(total_frames - delay + is_onset[0] * hop_s)
+        print "%f" % (this_onset / float(samplerate))
+        onsets.append(this_onset)
+    total_frames += read
+    if read < hop_s: break
+#print len(onsets)

diff --git a/python/demos/demo_onset_file.py b/python/demos/demo_onset_file.py
deleted file mode 100755 (executable)
index fe13cd7..0000000
--- a/python/demos/demo_onset_file.py
+++ /dev/null
@@ -1,65 +0,0 @@
-#! /usr/bin/env python
-
-import sys
-from aubio import onset, source
-from numpy import array, hstack, zeros
-
-win_s = 512                 # fft size
-hop_s = win_s / 2           # hop size
-samplerate = 44100
-downsample = 2              # used to plot n samples / hop_s
-
-if len(sys.argv) < 2:
-    print "Usage: %s <filename>" % sys.argv[0]
-    sys.exit(1)
-
-filename = sys.argv[1]
-onsets = []
-
-s = source(filename, samplerate, hop_s)
-o = onset("default", win_s, hop_s)
-
-desc = []
-tdesc = []
-
-block_read = 0
-allsamples_max = zeros(0,)
-while True:
-    samples, read = s()
-    new_maxes = (abs(samples.reshape(hop_s/downsample, downsample))).max(axis=0)
-    allsamples_max = hstack([allsamples_max, new_maxes])
-    isbeat = o(samples)
-    desc.append(o.get_descriptor())
-    tdesc.append(o.get_thresholded_descriptor())
-    if isbeat:
-        thisbeat = (block_read - 4. + isbeat[0]) * hop_s / samplerate
-        print "%.4f" % thisbeat
-        onsets.append (thisbeat)
-    block_read += 1
-    if read < hop_s: break
-
-if 1:
-    # do plotting
-    from numpy import arange
-    import matplotlib.pyplot as plt
-    allsamples_max = (allsamples_max > 0) * allsamples_max
-    allsamples_max_times = [ float(t) * hop_s / downsample / samplerate for t in range(len(allsamples_max)) ]
-    plt1 = plt.axes([0.1, 0.75, 0.8, 0.19])
-    plt2 = plt.axes([0.1, 0.1, 0.8, 0.65], sharex = plt1)
-    plt.rc('lines',linewidth='.8')
-    plt1.plot(allsamples_max_times,  allsamples_max, '-b')
-    plt1.plot(allsamples_max_times, -allsamples_max, '-b')
-    for stamp in onsets: plt1.plot([stamp, stamp], [-1., 1.], '-r')
-    plt1.axis(xmin = 0., xmax = max(allsamples_max_times) )
-    plt1.xaxis.set_visible(False)
-    plt1.yaxis.set_visible(False)
-    desc_times = [ float(t) * hop_s / samplerate for t in range(len(desc)) ]
-    desc_plot = [d / max(desc) for d in desc]
-    plt2.plot(desc_times, desc_plot, '-g')
-    tdesc_plot = [d / max(desc) for d in tdesc]
-    for stamp in onsets: plt2.plot([stamp, stamp], [min(tdesc_plot), max(desc_plot)], '-r')
-    plt2.plot(desc_times, tdesc_plot, '-y')
-    plt2.axis(ymin = min(tdesc_plot), ymax = max(desc_plot))
-    plt.xlabel('time (s)')
-    #plt.savefig('/tmp/t.png', dpi=200)
-    plt.show()

diff --git a/python/demos/demo_onset_plot.py b/python/demos/demo_onset_plot.py
new file mode 100755 (executable)
index 0000000..cfdf16b
--- /dev/null
+++ b/python/demos/demo_onset_plot.py
@@ -0,0 +1,74 @@
+#! /usr/bin/env python
+
+import sys
+from aubio import onset, source
+from numpy import array, hstack, zeros
+
+win_s = 512                 # fft size
+hop_s = win_s / 2           # hop size
+
+if len(sys.argv) < 2:
+    print "Usage: %s <filename> [samplerate]" % sys.argv[0]
+    sys.exit(1)
+
+filename = sys.argv[1]
+
+samplerate = 0
+if len( sys.argv ) > 2: samplerate = int(sys.argv[2])
+
+s = source(filename, samplerate, hop_s)
+samplerate = s.samplerate
+o = onset("default", win_s, hop_s)
+
+# onset detection delay, in blocks
+delay = 4. * hop_s
+
+onsets = []
+
+# storage for plotted data
+desc = []
+tdesc = []
+allsamples_max = zeros(0,)
+downsample = 2  # to plot n samples / hop_s
+
+total_frames = 0
+while True:
+    samples, read = s()
+    is_onset = o(samples)
+    if is_onset:
+        this_onset = int(total_frames - delay + is_onset[0] * hop_s)
+        print "%f" % (this_onset / float(samplerate))
+        onsets.append(this_onset / float(samplerate))
+    # keep some data to plot it later
+    new_maxes = (abs(samples.reshape(hop_s/downsample, downsample))).max(axis=0)
+    allsamples_max = hstack([allsamples_max, new_maxes])
+    desc.append(o.get_descriptor())
+    tdesc.append(o.get_thresholded_descriptor())
+    total_frames += read
+    if read < hop_s: break
+
+if 1:
+    # do plotting
+    from numpy import arange
+    import matplotlib.pyplot as plt
+    allsamples_max = (allsamples_max > 0) * allsamples_max
+    allsamples_max_times = [ float(t) * hop_s / downsample / samplerate for t in range(len(allsamples_max)) ]
+    plt1 = plt.axes([0.1, 0.75, 0.8, 0.19])
+    plt2 = plt.axes([0.1, 0.1, 0.8, 0.65], sharex = plt1)
+    plt.rc('lines',linewidth='.8')
+    plt1.plot(allsamples_max_times,  allsamples_max, '-b')
+    plt1.plot(allsamples_max_times, -allsamples_max, '-b')
+    for stamp in onsets: plt1.plot([stamp, stamp], [-1., 1.], '-r')
+    plt1.axis(xmin = 0., xmax = max(allsamples_max_times) )
+    plt1.xaxis.set_visible(False)
+    plt1.yaxis.set_visible(False)
+    desc_times = [ float(t) * hop_s / samplerate for t in range(len(desc)) ]
+    desc_plot = [d / max(desc) for d in desc]
+    plt2.plot(desc_times, desc_plot, '-g')
+    tdesc_plot = [d / max(desc) for d in tdesc]
+    for stamp in onsets: plt2.plot([stamp, stamp], [min(tdesc_plot), max(desc_plot)], '-r')
+    plt2.plot(desc_times, tdesc_plot, '-y')
+    plt2.axis(ymin = min(tdesc_plot), ymax = max(desc_plot))
+    plt.xlabel('time (s)')
+    #plt.savefig('/tmp/t.png', dpi=200)
+    plt.show()