[Matroska-devel] CodecPrivate for MPEG-1 and MPEG-2 video

Moritz Bunkus moritz at bunkus.org
Tue Nov 16 13:10:14 CET 2004


Let's talk about V_MPEG1 and V_MPEG2 :) Our specs page says:

  The matroska video stream will contain a demuxed Elementary Stream
  (ES), where block boundaries are still to be defined. Its recommended
  to use MPEG2MKV.exe for creating those files, and to compare the
  results with selfmade implementations

Spyder has told me he puts a sequence header into the CodecPrivate. The
sequence header contains information like width, height, FPS and pixel
aspect ratio among other things. While some of these fields are present
in the Matroska track headers others are not (like the picture coding
extension). So we cannot simply drop it.

Personally I'm voting for not putting anything into the the
CodecPrivate. At least not as mandatory information. The muxing app
MAY put a sequence header there, e.g. if the MPEG ES doesn't start with
one (every MPEG decoder needs a sequence header before it can decode the

Spyder? Any preference, additional thoughts?


If Darl McBride was in charge, he'd probably make marriage
unconstitutional too, since clearly it de-emphasizes the commercial
nature of normal human interaction, and probably is a major impediment
to the commercial growth of prostitution. - Linus Torvalds

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