[Ffmpeg-devel] An MPEG2/AC3 audio that ffmpeg cannot properlyidentify (or play)

Måns Rullgård mru
Thu Sep 22 17:26:02 CEST 2005

Nico Sabbi said:
> Ronen Mizrahi wrote:
>>>>   M?ns Rullg?rd wrote:
>>> That's only for DVD.  In general, private stream 1 can contain
>>> anything.  In this case it contains raw ac3 audio, no substreams or
>>> such things.
>>> What is the exact origin of this file?  DVB typically uses MPEG-TS,
>>> but this is MPEG-PS.  Has it been remuxed?  What software did you use
>>> to grab it?
> it know that it sucks, but I fixed mplayer's demuxer making it analyze the
> first 4 bytes of the pes payload when it finds a non recognized
> pes_private1 stream:
> if it finds 0b77 it assumes it's ac3

I figured that's what it was doing.  I'll do the same for lavf, since such
files are obviously being created, valid or not.  Strictly speaking, they
are valid, since the spec says nothing about the contents of private_stream_1,
hence the name.  I still consider it useful if we can detect common uses of
it, such as the DVD substreams for audio and subtitles.

M?ns Rullg?rd
mru at inprovide.com

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