[examples] Add time scaling example.

1 files changed, 34 insertions, 0 deletions

diff --git a/examples/timescale.py b/examples/timescale.py
new file mode 100644
index 0000000..a83916b
--- /dev/null
+++ b/examples/timescale.py
@@ -0,0 +1,34 @@
+import sys
+import numpy as np
+import scipy.io.wavfile as wav
+import simpl
+
+usage = 'Usage: python {0} '.format(__file__) + \
+    '<input wav file> <time scale factor> <output wav file>'
+
+if len(sys.argv) != 4:
+    print usage
+    sys.exit(1)
+
+audio = simpl.read_wav(sys.argv[1])[0]
+time_scale_factor = float(sys.argv[2])
+output_file = sys.argv[3]
+
+pd = simpl.LorisPeakDetection()
+peaks = pd.find_peaks(audio)
+pt = simpl.SMSPartialTracking()
+partials = pt.find_partials(peaks)
+
+synth = simpl.SndObjSynthesis()
+audio_out = np.array([])
+step_size = 1.0 / time_scale_factor
+current_frame = 0
+
+while current_frame < len(partials):
+    i = int(current_frame)
+    frame = synth.synth_frame(partials[i])
+    audio_out = np.hstack((audio_out, frame))
+    current_frame += step_size
+
+audio_out = np.asarray(audio_out * 32768, np.int16)
+wav.write(output_file, 44100, audio_out)