add energy(), spl(), and rms() methods to Signal and FramedSignal

CHANGES.rst

@@ -24,13 +24,15 @@ API relevant changes:
 
 Other changes:
 
+* SPL and RMS can be computed on `Signal` and `FramedSignal` (#208)
 * `num_threads` is passed to `ParallelProcessor` in single mode (#217)
 * Use `install_requires` in `setup.py` to specify dependencies (#226)
 * Use new Cython build system to build extensions (#227)
 * Allow initialisation of previous/hidden states in RNNs (#243)
 * Forward path of `HMM` can be computed stepwise (#244)
 
 
+
 Version 0.14.1 (release date: 2016-08-01)
 -----------------------------------------
 

madmom/audio/signal.py

@@ -797,6 +797,22 @@ def write(self, filename):
         """
         return write_wave_file(self, filename)
 
+    def energy(self):
+        """Energy of signal."""
+        return energy(self)
+
+    def root_mean_square(self):
+        """Root mean square of signal."""
+        return root_mean_square(self)
+
+    rms = root_mean_square
+
+    def sound_pressure_level(self):
+        """Sound pressure level of signal."""
+        return sound_pressure_level(self)
+
+    spl = sound_pressure_level
+
 
 class SignalProcessor(Processor):
     """
@@ -1298,6 +1314,22 @@ def ndim(self):
         """Dimensionality of the FramedSignal."""
         return len(self.shape)
 
+    def energy(self):
+        """Energy of the individual frames."""
+        return energy(self)
+
+    def root_mean_square(self):
+        """Root mean square of the individual frames."""
+        return root_mean_square(self)
+
+    rms = root_mean_square
+
+    def sound_pressure_level(self):
+        """Sound pressure level of the individual frames."""
+        return sound_pressure_level(self)
+
+    spl = sound_pressure_level
+
 
 class FramedSignalProcessor(Processor):
     """

tests/test_audio_signal.py

@@ -1007,6 +1007,19 @@ def test_write_method(self):
         result = Signal(tmp_file)
         self.assertTrue(np.allclose(orig, result))
 
+    def test_methods(self):
+        # mono signals
+        signal = Signal(sig_1d)
+        self.assertTrue(np.allclose(signal.energy(), 3))
+        self.assertTrue(np.allclose(signal.rms(), 0.57735026919))
+        self.assertTrue(np.allclose(signal.spl(), -4.7712125472))
+        # multi-channel signals
+        signal = Signal(sig_2d)
+        self.assertTrue(np.allclose(signal.energy(), 8))
+        self.assertTrue(np.allclose(signal.root_mean_square(), 2. / 3))
+        self.assertTrue(np.allclose(signal.sound_pressure_level(),
+                                    -3.52182518111))
+
 
 class TestSignalProcessorClass(unittest.TestCase):
 
@@ -1458,6 +1471,25 @@ def test_values_file_fps(self):
         self.assertTrue(result.frame_size == 2048)
         self.assertTrue(result.hop_size == 882.)
 
+    def test_methods(self):
+        # mono signals
+        frames = FramedSignal(sig_1d, frame_size=4, hop_size=2)
+        self.assertTrue(np.allclose(frames.energy(), [0, 1, 2, 1, 1]))
+        self.assertTrue(np.allclose(frames.rms(),
+                                    [0, 0.5, 0.70710678, 0.5, 0.5]))
+        self.assertTrue(np.allclose(frames.spl(),
+                                    [-np.finfo(float).max, -6.0206, -3.0103,
+                                     -6.0206, -6.0206]))
+        # multi-channel signals
+        frames = FramedSignal(sig_2d, frame_size=4, hop_size=2)
+        self.assertTrue(np.allclose(frames.energy(), [1, 3, 4, 3, 3]))
+        self.assertTrue(np.allclose(frames.root_mean_square(),
+                                    [0.35355339, 0.61237244, 0.70710678,
+                                     0.61237244, 0.61237244]))
+        self.assertTrue(np.allclose(frames.sound_pressure_level(),
+                                    [-9.03089987, -4.25968732, -3.01029996,
+                                     -4.25968732, -4.25968732]))
+
 
 class TestFramedSignalProcessorClass(unittest.TestCase):