refactor writing of tempo in MIREX format

bin/TempoDetector

@@ -9,13 +9,56 @@ from __future__ import absolute_import, division, print_function
 
 import argparse
 
+import numpy as np
+
 from madmom.audio import SignalProcessor
 from madmom.features import (ActivationsProcessor, RNNBeatProcessor,
                              TempoEstimationProcessor)
 from madmom.io import write_events, write_tempo
 from madmom.processors import IOProcessor, io_arguments
 
 
+def write_mirex(tempi, filename):
+    """
+    Write the most dominant tempi and the relative strength to a file (in
+    MIREX format).
+
+    Parameters
+    ----------
+    tempi : numpy array
+        Array with the detected tempi (first column) and their strengths
+        (second column).
+    filename : str or file handle
+        Output file.
+
+    """
+    # make the given tempi a 2d array
+    tempi = np.array(tempi, ndmin=2)
+    # default values
+    t1 = t2 = strength = np.nan
+    # only one tempo was detected
+    if len(tempi) == 1:
+        t1 = tempi[0][0]
+        strength = 1.
+        # generate a fake second tempo (safer to output a real value than NaN)
+        # the boundary of 68 bpm is taken from Tzanetakis 2013 ICASSP paper
+        if t1 < 68:
+            t2 = t1 * 2.
+        else:
+            t2 = t1 / 2.
+    # consider only the two strongest tempi and strengths
+    elif len(tempi) > 1:
+        t1, t2 = tempi[:2, 0]
+        strength = tempi[0, 1] / sum(tempi[:2, 1])
+    # for MIREX, the lower tempo must be given first
+    if t1 > t2:
+        t1, t2, strength = t2, t1, 1. - strength
+    # format as a numpy array
+    out = np.array([t1, t2, strength], ndmin=2)
+    # write to output
+    np.savetxt(filename, out, fmt=['%.2f', '%.2f', '%.2f'], delimiter='\t')
+
+
 def main():
     """TempoDetector"""
 
@@ -97,8 +140,7 @@ def main():
         # output handler
         if args.tempo_format == 'mirex':
             # output in the MIREX format (i.e. slower tempo first)
-            from functools import partial
-            output = partial(write_tempo, mirex=True)
+            output = write_mirex
         elif args.tempo_format in ('raw', 'all'):
             # borrow the event writer for outputting multiple values
             output = write_events

madmom/io/__init__.py

@@ -399,7 +399,7 @@ def load_tempo(filename, split_value=1., sort=None, norm_strengths=None,
     return np.vstack((tempi[:max_len], strengths[:max_len])).T
 
 
-def write_tempo(tempi, filename, delimiter='\t', mirex=False):
+def write_tempo(tempi, filename, delimiter='\t', mirex=None):
     """
     Write the most dominant tempi and the relative strength to a file.
 
@@ -426,23 +426,23 @@ def write_tempo(tempi, filename, delimiter='\t', mirex=False):
     # make the given tempi a 2d array
     tempi = np.array(tempi, ndmin=2)
     # default values
-    t1, t2, strength = 0., 0., 1.
+    t1 = t2 = strength = np.nan
     # only one tempo was detected
     if len(tempi) == 1:
         t1 = tempi[0][0]
-        # generate a fake second tempo
-        # the boundary of 68 bpm is taken from Tzanetakis 2013 ICASSP paper
-        if t1 < 68:
-            t2 = t1 * 2.
-        else:
-            t2 = t1 / 2.
+        strength = 1.
     # consider only the two strongest tempi and strengths
     elif len(tempi) > 1:
         t1, t2 = tempi[:2, 0]
         strength = tempi[0, 1] / sum(tempi[:2, 1])
     # for MIREX, the lower tempo must be given first
-    if mirex and t1 > t2:
-        t1, t2, strength = t2, t1, 1. - strength
+    if mirex is not None:
+        import warnings
+        warnings.warn('`mirex` argument is deprecated as of version 0.16 '
+                      'and will be removed in version 0.17. Please sort the '
+                      'tempi manually')
+        if t1 > t2:
+            t1, t2, strength = t2, t1, 1. - strength
     # format as a numpy array
     out = np.array([t1, t2, strength], ndmin=2)
     # write to output

tests/test_bin.py

@@ -1013,6 +1013,18 @@ def test_online(self):
         result = np.loadtxt(tmp_result)
         self.assertTrue(np.allclose(result, self.online_results))
 
+    def test_mirex(self):
+        run_single(self.bin, sample_file, tmp_result, args=['--mirex'])
+        result = np.loadtxt(tmp_result)
+        self.assertTrue(np.allclose(result, [117.65, 176.47, 0.27]))
+
+    def test_all_tempi(self):
+        run_single(self.bin, sample_file, tmp_result, args=['--all'])
+        result = np.loadtxt(tmp_result)
+        self.assertTrue(np.allclose(
+            result, [[176.471, 0.475], [117.647, 0.177], [240.000, 0.154],
+                     [68.966, 0.099], [82.192, 0.096]]))
+
 
 # clean up
 def teardown():

tests/test_features_tempo.py

@@ -418,10 +418,12 @@ def test_types(self):
     def test_values(self):
         # only one tempo given (>68 bpm)
         result = write_tempo(COMB_TEMPI[0], self.out_file)
-        self.assertTrue(np.allclose(result, [176.47, 88.235, 1], atol=0.001))
+        self.assertTrue(np.allclose(result, [176.47, np.nan, 1],
+                                    atol=1e-4, equal_nan=True))
         # only one tempo given (<68 bpm)
         result = write_tempo(COMB_TEMPI[3] / 2, self.out_file)
-        self.assertTrue(np.allclose(result, [34.483, 68.966, 1], atol=0.01))
+        self.assertTrue(np.allclose(result, [34.483, np.nan, 1],
+                                    atol=1e-4, equal_nan=True))
         # multiple tempi given
         result = write_tempo(COMB_TEMPI, self.out_file)
         self.assertTrue(np.allclose(result, [176.47, 117.647, 0.728],