[mythtv] Question on Xv output and NuppelVideoPlayer

Clyde Stubbs clyde at htsoft.com
Fri Jul 2 20:07:29 EDT 2004

On Fri, Jul 02, 2004 at 11:40:49AM -0400, Isaac Richards wrote:
> event from XvPutImage is sent.  If the driver implementation signals that 
> it's done with the PutImage before it's actually put the image, that's kind 
> of broken, no?

That's my point. After XSync you are assured that the video card has
been instructed to display the image, but not that it has actually done

The other, quite orthogonal, point is that the existing videoout_xv code assumes that the XSync
*initiates* the display of the image, which it clearly doesn't. In the
OldAVSync case, that's unimportant since PrepareFrame and Show are simply
called one after the other, but the ExAVSync code calls PrepareFrame, then
delays, then calls Show. In the usual case where the frame rate is half the
refresh rate this could result in a frame being shown one field early.

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