[mythtv] LiveTV Playback Real Time Problems

Paul Sykes pdsykes at gmail.com
Wed Nov 24 18:45:58 UTC 2004


Hi,

I hope that this is the right list to send this message to, but I have
had no luck trying the users list.

I have a problem with the playback of my LiveTV on a Hauppauge Nova-T
USB.  The initial problem was that everything, both sound and video,
were played slowly.  This would mean that the current position of the
video stream would fall further and further behind as time progressed.
It would loose about 5 minutes every hour.

I have sort of fixed this with a mixture of recompiling the kernel
less various options and compiling a CVS version of MythTV.  I
eventually tracked it down to the enhanced real time clock option in
the kernel menuconfig.  Once I had removed this option it fixed the
video playing slowly.  Namely I suspect because the frontend stopped
using RTC and used a USleep method.

However, it did not entirely fix the problem.  Although I could watch
BBC News 24 and the clock on the screen would stay correct, the timer
telling you where you were in the LiveTV stream continues to fall
behind in time.  This is only a problem when I try and pause or skip
back in LiveTV, when I do this is skips from the position the timer
thinks it is in the livetv stream, and not where it actually is.

I have tried various kernel options, including HPET and nothing has
helped, all I know is that the video and sound both slow down when I
enable the enhanced real time clock option.

If anybody could help me I would be most grateful as it is a mildly
irritating bug.  If there is any advice on kernel options that may
help please could you let me know what they are.

If anybody knows what mythtv uses as a timer, ie. what the RTC and
USleep modes are then this may help solve the problem.  I would also
be willing to post my kernel configuration and full hardware list if
this would help.

Thanks in advance.

Paul


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