[mythtv-users] mplayer -dumpstream better than myth record

Ben bluey at iguanaworks.net
Sat Sep 15 01:14:41 UTC 2007


Hunter McDaniel wrote:
> I'm wondering if your problem is that same as what I have with one 
> particular channel, KTVD-DT in Denver.
> Reception of this channel is rock-solid on a standard STB, and Myth has 
> no problem with three other stations whose transmitters are located on 
> the very same building with comparable power levels.
>
> I did a bit of investigation a few months ago, and like you, found that 
> I could record my problem channel just fine with mplayer --dumpstream, 
> but trying to watch or record it with Myth always gave me freezes and 
> lockups.  When I turned on some of the detailed logging in the backend, 
> I saw that Myth was constantly detecting "discontinuity errors" in the 
> PMT, and the logic to recover from those discontinuities seemed to be 
> overwhelm the recording process, saturating the CPU and making it drop 
> frames.  From a more detailed look at the actual frames, I could see 
> that the datastream from KTVD-DT had two different PMTs interleaved into 
> it, each running a different continuity counter - and hence causing a 
> discontinuity on every PMT.
>
> I don't know if the problem with your station is the same, but it might 
> be worth a check.
>   
Yup, that's it. I'm in Denver and the station giving me all these 
troubles is KTVD... and the problems is exactly as you've described. I  
think I'm having the same problem with FOX (KDVR) only to a much lesser 
degree, but I could be wrong. Have you found any solution to this PMT 
problem?

Thanks,

Ben



More information about the mythtv-users mailing list