[mythtv] HD-3000 and changes from 18.1 to SVN

[Daniel Kristjansson]

On Wed, 2005-10-26 at 19:30 -0600, Chris Dos wrote:

> AFD: Looking for decoder for MPEG2VIDEO_XVMC
> AFD: Opened codec 0x8da96c0, id(MPEG2VIDEO_XVMC) type(Video)
> Estimated bitrate = 8000
> * Does this mean the estimated bitrate that the buffer needs?  I'm running 24360 
> right now.
No, this means the estimated bitrate of the stream, it is used to
set the sizes of buffers for LiveTV and network streaming. If you
are getting playback problem while playing an existing recording
this isn't the problem.

> VideoOutputXv: ctor
> * I don't know what ctor means.
constructor

> VideoOutputXv: XvMC surface found with IDCT support on port 240
> Image size. dispxoff 0, dispyoff: 0, dispwoff: 1280, disphoff: 720
> Image size. imgx 0, imgy: 0, imgw: 1920, imgh: 1080
> * So it looks like XvMC created a 1280x720 screen and the signal that I was 
> trying to watch was 1920x1080.  Shouldn't that in reality be 1920x540?
Nope it should be 1920x1080, this is the size of each frame. When playing
an interlaced 1920x1080 frame it is the monitor's job to only one field
at a time. If the monitor is incapable of that MythTV can use
bob-deinterlacing to simulate the effect.

> Using OpenGLVideoSync
This is good.

> Set video sync frame interval to 33366
> Refresh rate: 16683, frame interval: 33366
> * It says it's using OpenVLVideoSync.  But I don't understand what value's the 
> refresh rate and frame intervals tell me.
This is pretty good. These rates are in microseconds. It is only when 
the refresh rate is not evenly divisible into the frame interval that 
you have get jitter. In your case the monitor is running at 59.94 
frames per second, and the video at 29.97 frames per second,
aka 59.94 1920x540 fields per second. To convert to the rate values
to fps, divide 1 second or 1000000 microseconds by those values.

> Do these log snippets provide any information that might point to the cause of 
> my problem?  Thanks again for your time in looking at this.
Nope, but you've eliminated jitter as the cause of the "frames ahead
of video" messages though. My best bet is that the sound card is 
running a little fast. You can try playing with the values for 
audio buffering, or use the video as the timebase instead. 
Or, if you have a spare audio card, try using it instead.

However, my guess is that this isn't your real problem. I think
your system is just too marginal to use nVidia's implementation
of XvMC for HDTV sized frames. The only thing you can really at
this point is the chromakey OSD. This might make HDTV work for
you (though probably not when the OSD is on screen.)

You can try the users list, I've learned some from searching there;
and some people claim HDTV on some rather limited machines.

-- Daniel