[linux-dvb] Re: The origin of the pts ?

[Peter Maersk-Moller <peter@maersk-moller.net>]

Hi Johannes

Thanks for answering.

Johannes Stezenbach wrote:
> Peter Maersk-Moller wrote:
> > Every now and then I seem to encounter PTS-values which seems to
> > be less than their predecessor. As far as I remember, then the
> > MPEG-2 TS is recreated by TT budget/Full card thus creating
> > some of the header data on the-fly instead of just relaying data
> > exact as it was recived. Is this correct ?
> No.
> > If yes, is the PTS
> > then recreated by the DVB card or is it just relayed as-is ?
> As-Is, except is your record the same video/audio PID on a av7110
> based card which are currently being decoded (this is a hardware
> limitation).
Do you mean, that on a premium TT board, part of the stream (or headers)
is created on the fly ?

> > The reason I'm asking is that every now and then I seem to get
> > a PTS of a frame belonging in the past. See the log below, where I
> > receive data with a TT Budget (NOVA-s), broadcast with dvbstream,
> > receive and decode with libmpeg2 (in mp4live).
> Frames are sent in decoding order, not in display order.
> (which is different in the presence of B-frames).
The TS stream is demuxed and fed to libmpeg2 as it is received.
Decoded frames are read in display order. As you can see
on the log, the jump backward in pts happens with minutes
in-between.

I'll search on for the cause. If anybody else see this problem, please let me
know.

Kind regards

--PMM