From 07867cd07ec04d24b226b6af55ddaeac56be5665 Mon Sep 17 00:00:00 2001
From: Paul Brossier <piem@piem.org>
Date: Mon, 25 Apr 2016 18:56:13 +0200
Subject: [PATCH] demos/demo_reading_speed.py: add reading speed tests

---
 python/demos/demo_reading_speed.py | 86 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 python/demos/demo_reading_speed.py

diff --git a/python/demos/demo_reading_speed.py b/python/demos/demo_reading_speed.py
new file mode 100644
index 00000000..e6fdb78d
--- /dev/null
+++ b/python/demos/demo_reading_speed.py
@@ -0,0 +1,86 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+
+Compare the speed of several methods for reading and loading a sound file.
+
+This file depends on audioread and librosa:
+    https://github.com/beetbox/audioread
+    https://github.com/bmcfee/librosa
+
+"""
+
+import numpy as np
+import aubio
+import audioread
+import librosa
+
+def read_file_audioread(filename):
+    # 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)
+        out = out.reshape(2, -1)
+        return out
+
+    with audioread.audio_open(filename) as f:
+        total_frames = 0
+        for buf in f:
+            samples = convert_buffer_to_float(buf)
+            total_frames += samples.shape[1]
+        return total_frames, f.samplerate
+
+def load_file_librosa(filename):
+    y, sr = librosa.load(filename, sr = None)
+    return len(y), sr
+
+def read_file_aubio(filename):
+    f = aubio.source(filename, hop_size = 1024)
+    total_frames = 0
+    while True:
+        samples, read = f()
+        total_frames += read
+        if read < f.hop_size: break
+    return total_frames, f.samplerate
+
+def load_file_aubio(filename):
+    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
+    return total_frames, f.samplerate
+
+def test_speed(function, filename):
+    times = []
+    for i in range(10):
+        start = time.time()
+        total_frames, samplerate = function(filename)
+        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]
+
+    functions = [read_file_aubio, load_file_aubio, read_file_audioread, load_file_librosa]
+    for f in functions:
+        test_speed(f, filename)
-- 
2.11.0