[mythtv] dvb zero length record

Daniel Kristjansson danielk at cat.nyu.edu
Mon Jun 6 11:33:15 UTC 2005

On Mon, 2005-06-06 at 20:56 +1000, Phil Vid wrote:
> This has been resolved by turning off the 'Wait for SEQ Start Header'
> flag in the DVB card setup. Thanks Will Uther for suggesting this fix.
> Unfortunately I don't have any experience with MPEG video stream
> decoding, so is anyone able to explain why this is necessary and what
> the purpose of the sequence frame wait is?
We try to wait for the sequence start header as a proxy for waiting for
the first I frame. The reason we want to wait for the first I frame is
two fold: first ffmpeg used to crash the program when you didn't, second
if you don't wait for the first I frame then you can get weird visual
effects as partial P and B frames arrive before the first full frame.

-- Daniel

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