def decodeBegin(self):
# A dummy packet that is used to pass the output buffer to avcodec_decode_audio3
self._dummyPkt = decls.AVPacket()
avcodec.av_init_packet(self._dummyPkt)
# Allocate a buffer for the decoded audio frame
size = 192000
self._sampleBuf = (size*ctypes.c_short)()
self._audioData = AudioData(self, channels=self._codecCtx.channels, framerate=self._codecCtx.sample_rate, samples=self._sampleBuf)
return True
def iterData(self, streams=None):
"""Iterate over the frames of the first video stream.
"""
# Use the first video stream by default...
if streams is None:
if len(self.videoStreams)==0:
return
videoStream = self.videoStreams[0]
streams = [videoStream]
if len(streams)==0:
return
# Initialize the streams...
# streamDict: Key:Stream index - Value:Stream object
streamDict = {}
for stream in streams:
# Check the type of the stream
if not isinstance(stream, StreamBase_ffmpeg):
raise TypeError("Stream object expected")
# Is this a stream from someone else?
if stream not in self._streams:
raise ValueError("Invalid stream (stream is from a different source)")
stream.decodeBegin()
streamDict[stream.index] = stream
try:
# Iterate over the packets in the file and decode the frames...
for pkt in self.iterPackets():
stream = streamDict.get(pkt.stream_index, None)
if stream is not None:
for data in stream.handlePacket(pkt):
yield data
# Some codecs have a delay between input and output, so go on
# feeding empty packets until we receive no more frames.
pkt = decls.AVPacket()
avcodec.av_init_packet(pkt)
for stream in streamDict.values():
hasData = True
while hasData:
hasData = False
for data in stream.handlePacket(pkt):
hasData = True
yield data
finally:
for stream in streamDict.values():
stream.decodeEnd()
def writeFrame__dummy(self):
# Create a packet struct and initialize it
pkt = AVPacket()
avcodec.av_init_packet(pkt)
#pkt.stream_index = outputstream.index
#big_picture.pts= ost->sync_opts;
# Encode the frame
bytes = avcodec.avcodec_encode_video(codecCtx, buf, bufsize, picture)
if bytes>0:
pkt.data = buf
pkt.size = bytes
# pkt.pts = ...
if codecCtx.coded_frame.key_frame:
pkt.flags |= PKT_FLAG_KEY
avformat.av_interleaved_write_frame(formatCtx, pkt)
