def _parse_stream(self):
while True:
strl = self._next_chunk()
# search for next LIST/strl chunk
if strl.fcc == b"LIST" and strl.sub_fcc == b"strl":
break
# skip LIST/odml chunks
elif strl.fcc == b"LIST" and strl.sub_fcc == b"odml":
self._skip_chunk(strl)
# back up if anything else is found
else:
self._put_back(strl)
return False
self._log.write("Stream definition #{0}".format(len(self._stream_data)))
strh = self._require_chunk(b"strh")
stream_header = self._read_struct_chunk(strh, StreamHeader)
self._log.write("Stream header")
self._log.writeobj(stream_header)
bitmap_info = None
strf = self._require_chunk(b"strf")
if stream_header.fccType == b"vids":
bitmap_info = self._read_struct_chunk(strf, BitmapInfoHeader)
self._log.write("Bitmap info header")
self._log.writeobj(bitmap_info)
else:
self._skip_chunk(strf)
codec_data = None
c = self._next_chunk()
if c.fcc == b"strd":
codec_data = self._read_chunk_content(c)
self._log.write("Codec data: {0} bytes", len(codec_data))
c = self._next_chunk()
stream_name = None
if c.fcc == b"strn":
stream_name = _from_asciiz(self._read_chunk_content(c))
self._log.write("Stream name: {0!r}", stream_name)
else:
self._put_back(c)
if bitmap_info is not None:
vs = InputVideoStream(self)
vs.stream_num = len(self._stream_data)
vs.width = bitmap_info.Width
vs.height = bitmap_info.Height
vs.frame_rate = Timecode.interpret_frame_rate(
stream_header.Rate / float(stream_header.Scale))
vs.codec = stream_header.fccHandler
vs.codec_data = codec_data
vs.suggested_buffer_size = stream_header.SuggestedBufferSize
vs.bit_depth = bitmap_info.BitCount
vs.compression = bitmap_info.Compression
vs.size_image = bitmap_info.SizeImage
self.video_streams.append(vs)
self._stream_data.append(StreamInfo(
stream_header, bitmap_info, codec_data, stream_name))
return True
def microseconds_per_frame(self):
return round(1e6 / Timecode.interpret_frame_rate(self.frame_rate))
