decoder

mp4/decoder.py

@@ -5,7 +5,7 @@ from .packet import Packet
 from .frame import Frame
 
 class Decoder:
-    __slots__ = '_context', '_index'
+    __slots__ = '_context'
 
     def __init__(self, stream):
         self._context = libav.codec_alloc_context(stream.codec)
@@ -19,7 +19,6 @@ class Decoder:
         if errcode < 0:
             libav.codec_free_context(self._context)
             raise Exception("Failed to open codec context")
-        self._index = 0
 
     def __del__(self):
         if self._context:
@@ -46,3 +45,6 @@ class Decoder:
             errstring = libav.strerror(errcode)
             raise Exception(f"Failed to send packet: {errstring}")
         return self._receive()
+
+    def flush(self):
+        return self.decode(None)

mp4/demuxer.py

@@ -22,6 +22,12 @@ class Demuxer:
         self.video_stream = self._find_stream(libav.AVMEDIA_TYPE_VIDEO)
         self.audio_stream = self._find_stream(libav.AVMEDIA_TYPE_AUDIO)
 
+    @property
+    def nb_streams(self):
+        if not self._context:
+            return 0
+        return self._context.contents.nb_streams
+
     def _find_stream(self, type):
         index, codec_ref = libav.format_find_best_stream(self._context, type)
         if index < 0 or not codec_ref:

pve.py

@@ -5,8 +5,9 @@ from mp4.decoder import Decoder
 
 demuxer = Demuxer('test.mp4')
 
-print(demuxer.video_stream.codec.name)
-print(demuxer.audio_stream.codec.name)
+print(f"nb_streams  = {demuxer.nb_streams}")
+print(f"video codec = {demuxer.video_stream.codec.name}")
+print(f"audio codec = {demuxer.audio_stream.codec.name}")
 
 video_decoder = Decoder(demuxer.video_stream)
 audio_decoder = Decoder(demuxer.audio_stream)
@@ -26,10 +27,10 @@ while True:
     else:
         print("unkown packet")
 
-video_frames = video_decoder.decode(None)
+video_frames = video_decoder.flush()
 print(f"flushed {len(video_frames)} video frames")
 
-audio_frames = audio_decoder.decode(None)
+audio_frames = audio_decoder.flush()
 print(f"flushed {len(audio_frames)} audio frames")
 
 demuxer.close()