Fix AudioClip I/O

moviepy/audio/AudioClip.py

@@ -246,8 +246,8 @@ def make_frame(t):
             is a list of the form sin(t) """
 
             if isinstance(t, np.ndarray):
-                array_inds = (self.fps*t).astype(int)
-                in_array = (array_inds > 0) & (array_inds < len(self.array))
+                array_inds = np.round(self.fps*t).astype(int)
+                in_array = (array_inds >= 0) & (array_inds < len(self.array))
                 result = np.zeros((len(t), 2))
                 result[in_array] = self.array[array_inds[in_array]]
                 return result

moviepy/audio/io/readers.py

@@ -119,6 +119,9 @@ def read_chunk(self,chunksize):
         result = (1.0*result / 2**(8*self.nbytes-1)).\
                                  reshape((int(len(result)/self.nchannels),
                                           self.nchannels))
+        pad = np.zeros((chunksize - len(result), self.nchannels),
+                       dtype=result.dtype)
+        result = np.concatenate([result, pad])
         #self.proc.stdout.flush()
         self.pos = self.pos+chunksize
         return result
@@ -168,7 +171,7 @@ def get_frame(self, tt):
             if not in_time.any():
                 raise IOError("Error in file %s, "%(self.filename)+
                        "Accessing time t=%.02f-%.02f seconds, "%(tt[0], tt[-1])+
-                       "with clip duration=%d seconds, "%self.duration)
+                       "with clip duration=%f seconds, "%self.duration)
 
             # The np.round in the next line is super-important.
             # Removing it results in artifacts in the noise.
@@ -187,8 +190,6 @@ def get_frame(self, tt):
             try:
                 result = np.zeros((len(tt),self.nchannels))
                 indices = frames - self.buffer_startframe
-                if len(self.buffer) < self.buffersize // 2:
-                    indices = indices - (self.buffersize // 2 - len(self.buffer) + 1)
                 result[in_time] = self.buffer[indices]
                 return result
 
@@ -234,7 +235,7 @@ def buffer_around(self,framenumber):
                         current_f_end  <
                                new_bufferstart + self.buffersize):
                 # We already have one bit of what must be read
-                conserved = current_f_end - new_bufferstart + 1
+                conserved = current_f_end - new_bufferstart
                 chunksize = self.buffersize-conserved
                 array = self.read_chunk(chunksize)
                 self.buffer = np.vstack([self.buffer[-conserved:], array])

tests/test_AudioClips.py

@@ -4,10 +4,12 @@
 import sys
 
 import pytest
+import numpy as np
 from numpy import pi, sin
 
-from moviepy.audio.AudioClip import (AudioClip, CompositeAudioClip,
-                                     concatenate_audioclips)
+from moviepy.audio.AudioClip import (
+    AudioClip, AudioArrayClip, CompositeAudioClip, concatenate_audioclips
+)
 from moviepy.audio.io.AudioFileClip import AudioFileClip
 
 from .test_helper import TMP_DIR
@@ -29,6 +31,22 @@ def test_audioclip():
     clip = AudioClip(make_frame, duration=2, fps=22050)
     clip.write_audiofile(os.path.join(TMP_DIR, "audioclip.mp3"))
 
+def test_audioclip_io():
+    # Generate a random audio clip of 4.989 seconds at 44100 Hz,
+    # and save it to a file.
+    input_array = np.random.random((220000, 2)) * 1.98 - 0.99
+    clip = AudioArrayClip(input_array, fps=44100)
+    clip.write_audiofile(os.path.join(TMP_DIR, "random.wav"))
+    # Load the clip.
+    # The loaded clip will be slightly longer because the duration is rounded
+    # up to 4.99 seconds.
+    # Verify that the extra frames are all zero, and the remainder is identical
+    # to the original signal.
+    clip = AudioFileClip(os.path.join(TMP_DIR, "random.wav"))
+    output_array = clip.to_soundarray()
+    assert np.abs(output_array[:len(input_array)] - input_array).max() < 4e-5
+    assert (output_array[len(input_array):] == 0).all()
+
 def test_audioclip_concat():
     make_frame_440 = lambda t: [sin(440 * 2 * pi * t)]
     make_frame_880 = lambda t: [sin(880 * 2 * pi * t)]