decoder multithreading

pve.py

@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU General Public License along with People's Video Editor.
 # If not, see <https://www.gnu.org/licenses/>.
 
+import multiprocessing
 import cProfile
 
 from pyav.demuxer import Demuxer
@@ -25,10 +26,15 @@ print(f"nb_streams  = {demuxer.nb_streams}")
 print(f"video codec = {demuxer.video_stream.codec.description()}")
 print(f"audio codec = {demuxer.audio_stream.codec.description()}")
 
-video_decoder = Decoder(demuxer.video_stream)
-audio_decoder = Decoder(demuxer.audio_stream)
+cpu_count = multiprocessing.cpu_count()
 
-num_frames = 0
+print(f"using {cpu_count} threads for video decoding")
+
+video_decoder = Decoder(demuxer.video_stream, cpu_count)
+audio_decoder = Decoder(demuxer.audio_stream, 1)
+
+num_video_frames = 0
+num_audio_frames = 0
 
 with cProfile.Profile() as pr:
     while True:
@@ -36,13 +42,12 @@ with cProfile.Profile() as pr:
         eof = (packet is None)
         if eof or demuxer.video_stream.contains(packet):
             video_frames = video_decoder.decode(packet)
-            num_frames += len(video_frames)
-            # print(f"decoded {len(video_frames)} video frames")
+            num_video_frames += len(video_frames)
         if eof or demuxer.audio_stream.contains(packet):
             audio_frames = audio_decoder.decode(packet)
-            # print(f"decoded {len(audio_frames)} audio frames")
+            num_audio_frames += len(audio_frames)
         if eof:
             break
 
-print(f"num frames: {num_frames}")
+print(f"num video frames: {num_video_frames}, audio frames: {num_audio_frames}")
 pr.print_stats()