1 files changed, 139 insertions, 0 deletions
diff --git a/python/demos/demo_reading_speed.py b/python/demos/demo_reading_speed.py
new file mode 100755
index 0000000..90739f3
--- /dev/null
+++ b/python/demos/demo_reading_speed.py
@@ -0,0 +1,139 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+
+Compare the speed of several methods for reading and loading a sound file.
+
+Optionally, this file can make use of the following packages:
+
+    - audioread     https://github.com/beetbox/audioread
+    - scipy         https://scipy.org
+    - librosa       https://github.com/bmcfee/librosa
+    - pydub         https://github.com/jiaaro/pydub
+
+Uncomment the function names below and send us your speed results!
+
+"""
+
+
+test_functions = [
+            "read_file_aubio",
+            "load_file_aubio",
+            #"load_file_scipy",
+            #"load_file_scipy_mmap",
+            #"read_file_audioread",
+            #"load_file_librosa",
+            #"read_file_pydub",
+            #"load_file_pydub",
+            ]
+
+
+import numpy as np
+
+def read_file_audioread(filename):
+    import audioread
+    # taken from librosa.util.utils
+    def convert_buffer_to_float(buf, n_bytes = 2, dtype = np.float32):
+        # Invert the scale of the data
+        scale = 1./float(1 << ((8 * n_bytes) - 1))
+        # Construct the format string
+        fmt = '<i{:d}'.format(n_bytes)
+        # Rescale and format the data buffer
+        out = scale * np.frombuffer(buf, fmt).astype(dtype)
+        return out
+
+    with audioread.audio_open(filename) as f:
+        total_frames = 0
+        for buf in f:
+            samples = convert_buffer_to_float(buf)
+            samples = samples.reshape(f.channels, -1)
+            total_frames += samples.shape[1]
+        return total_frames, f.samplerate
+
+def load_file_librosa(filename):
+    import librosa
+    y, sr = librosa.load(filename, sr = None)
+    #print y.mean(), y.shape
+    return len(y), sr
+
+def load_file_scipy(filename):
+    import scipy.io.wavfile
+    sr, y = scipy.io.wavfile.read(filename)
+    y = y.astype('float32') / 32767
+    #print y.mean(), y.shape
+    return len(y), sr
+
+def load_file_scipy_mmap(filename):
+    import scipy.io.wavfile
+    sr, y = scipy.io.wavfile.read(filename, mmap = True)
+    #print y.mean(), y.shape
+    return len(y), sr
+
+def read_file_pydub(filename):
+    from pydub import AudioSegment
+    song = AudioSegment.from_file(filename)
+    song.get_array_of_samples()
+    return song.frame_count(), song.frame_rate
+
+def load_file_pydub(filename):
+    from pydub import AudioSegment
+    song = AudioSegment.from_file(filename)
+    y = np.asarray(song.get_array_of_samples(), dtype = 'float32')
+    y = y.reshape(song.channels, -1) / 32767.
+    return song.frame_count(), song.frame_rate
+
+def read_file_aubio(filename):
+    import aubio
+    f = aubio.source(filename, hop_size = 1024)
+    total_frames = 0
+    while True:
+        _, read = f()
+        total_frames += read
+        if read < f.hop_size: break
+    return total_frames, f.samplerate
+
+def load_file_aubio(filename):
+    import aubio
+    f = aubio.source(filename, hop_size = 1024)
+    y = np.zeros(f.duration, dtype = aubio.float_type)
+    total_frames = 0
+    while True:
+        samples, read = f()
+        y[total_frames:total_frames + read] = samples[:read]
+        total_frames += read
+        if read < f.hop_size: break
+    assert len(y) == total_frames
+    #print y.mean(), y.shape
+    return total_frames, f.samplerate
+
+def test_speed(function, filename):
+    times = []
+    for _ in range(10):
+        start = time.time()
+        try:
+            total_frames, samplerate = function(filename)
+        except ImportError as e:
+            print ("error: failed importing {:s}".format(e))
+            return
+        elapsed = time.time() - start
+        #print ("{:5f} ".format(elapsed)),
+        times.append(elapsed)
+
+    #print
+    times = np.array(times)
+    duration_min = int(total_frames/float(samplerate) // 60)
+    str_format = '{:25s} took {:5f} seconds avg (±{:5f}) to run on a ~ {:d} minutes long file'
+    print (str_format.format(function.__name__, times.mean(), times.std(), duration_min ))
+
+if __name__ == '__main__':
+    import sys, time
+    if len(sys.argv) < 2:
+        print ("not enough arguments")
+        sys.exit(1)
+    filename = sys.argv[1]
+
+    for f in test_functions:
+        # get actual function from globals
+        test_function = globals()[f]
+        test_speed(test_function, filename)