[mythtv-users] A/V delay when recording HD

[Florin Andrei]

Brad Fuller wrote:
> 
> AFA your captured stream: I assume you captured a QAM256 stream from
> the coax since you are using HDHR.

Well, forget the OP, explain my situation. :-)
So yeah, it's a QAM256 (I *think* it's 256), recorded by MythTV from an 
HDHR tuner, from a regular Comcast cable feed. MPEG2 1080i. Upon 
analysis, the A and V tracks in the .mpg file turned out to be not 
aligned, there's an A/V timing difference slightly bigger than 1000ms.

MythTV and pretty much any player is aware of the difference and the 
file is played in sync. So it looks like the timing diff is done on 
purpose by some component of the recording chain, and the whole thing is 
done properly.

My question was - why are not A and V muxed in sync? Why there's a time 
delta at all? For some reason, I expected a file dumped from a broadcast 
feed to have A and V in sync, with a 0 ms difference in between.

-- 
Florin Andrei

http://florin.myip.org/