Merge pull request #130 from aestrivex/add_movie_bitrate_api

add bitrate option to ffmpeg call

Author: larsoner

surfer/utils.py

@@ -655,7 +655,7 @@ def assert_ffmpeg_is_available():
 requires_ffmpeg = np.testing.dec.skipif(not has_ffmpeg(), 'Requires FFmpeg')
 
 
-def ffmpeg(dst, frame_path, framerate=24, codec='mpeg4'):
+def ffmpeg(dst, frame_path, framerate=24, codec='mpeg4', bitrate='1M'):
     """Run FFmpeg in a subprocess to convert an image sequence into a movie
 
     Parameters
@@ -671,6 +671,9 @@ def ffmpeg(dst, frame_path, framerate=24, codec='mpeg4'):
         Codec to use (default 'mpeg4'). If None, the codec argument is not
         forwarded to ffmpeg, which preserves compatibility with very old
         versions of ffmpeg
+    bitrate : str | float
+        Bitrate to use to encode movie. Can be specified as number (e.g.
+        64000) or string (e.g. '64k'). Default value is 1M
 
     Notes
     -----
@@ -696,7 +699,7 @@ def ffmpeg(dst, frame_path, framerate=24, codec='mpeg4'):
     frame_dir, frame_fmt = os.path.split(frame_path)
 
     # make the movie
-    cmd = ['ffmpeg', '-i', frame_fmt, '-r', str(framerate)]
+    cmd = ['ffmpeg', '-i', frame_fmt, '-r', str(framerate), '-b', str(bitrate)]
     if codec is not None:
         cmd += ['-c', codec]
     cmd += [dst]

surfer/viz.py

@@ -2122,7 +2122,8 @@ def save_montage(self, filename, order=['lat', 'ven', 'med'],
         return out
 
     def save_movie(self, fname, time_dilation=4., tmin=None, tmax=None,
-                   framerate=24, interpolation='quadratic', codec='mpeg4'):
+                   framerate=24, interpolation='quadratic', codec='mpeg4',
+                   bitrate='1M'):
         """Save a movie (for data with a time axis)
 
         .. Warning::
@@ -2150,6 +2151,9 @@ def save_movie(self, fname, time_dilation=4., tmin=None, tmax=None,
             'cubic', default 'quadratic').
         codec : str
             Codec to use with ffmpeg (default 'mpeg4').
+        bitrate : str | float
+            Bitrate to use to encode movie. Can be specified as number (e.g.
+            64000) or string (e.g. '64k'). Default value is 1M
 
         Notes
         -----
@@ -2192,7 +2196,7 @@ def save_movie(self, fname, time_dilation=4., tmin=None, tmax=None,
         fname_pattern = os.path.join(tempdir, frame_pattern)
         self.save_image_sequence(time_idx, fname_pattern, False, -1, -1,
                                  'current', interpolation=interpolation)
-        ffmpeg(fname, fname_pattern, framerate, codec)
+        ffmpeg(fname, fname_pattern, framerate, codec=codec, bitrate=bitrate)
 
     def animate(self, views, n_steps=180., fname=None, use_cache=False,
                 row=-1, col=-1):