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

Chris Dos chris at chrisdos.com
Thu Oct 27 15:29:12 UTC 2005


 > Daniel Kristjansson wrote:
> 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.

Yea, but could this be the difference between the 18.1 that I have that works 
using XvMC and the current SVN that does not.


>>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.

Tried the various settings.  Using the Extra Audio Buffering option causes a 
blue screen to be displayed when trying to watch HD.  In fact I have to reboot 
to reset the card so I can see HD again.  Using the video as the timebase also 
did not make a difference.

I have a sound blaster audigy card I can plug in.  I originally did buy it for 
my Myth box, but took it out when the onboard VIA sound was working and 
providing more options for 7.l sound.  I'll try the sound blaster card again and 
post the results.

> 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.)

I don't understand how my system is too marginal to play XvMC.  If I can do 
software decoding now using libmpeg2, I certainly have enough power to do XvMC. 
  When XvMC is working on the 18.1, it's only using 30% processor to decode HD. 
  I still think there is a problem in the changes for SVN compared to the 18.1 
that works fine except for the OSD dropped frames problem.

I enabled chromakey OSD and the problems still exist.

I'm starting to think that this might be a problem relating to AMD processors as 
Todd Freeman was also having this problem and his system is 1/3 faster than 
mine.  If I remember right, you have an Intel processor and looking at the 
mailing list, most people that are doing HD are using the Intel procs.  Are 
there any source files in my 18.1 tree that you would want to take a look at to 
look at the differences in the code?

I would like to find a solution to this if at all possible.

	Chris


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