On Thu, Jul 8, 2010 at 5:33 PM, Ivan <[email protected]> wrote:
> Ok, the horizontal shift disappears if I switch to 720x480 instead of
> 640x480.
>
> Does the card always output 720x480 (in NTSC mode anyway), then, and any
> scaling is done by V4L?

That card does have an onboard scaler, although it's not clear to me
why it isn't working.  Exactly what command line did you use?

> I also have a question about dropped frames. After running mplayer or
> mencoder, I see a line like:
>
> v4l2: 1199 frames successfully processed, -3 frames dropped.
>
> I can only guess that the negative number means that V4L received frames at
> a slightly faster rate than the expected 30000/1001 fps. In my case, it
> would seem that my SNES is producing something more like 30.05 fps, and so
> V4L reports a "negative" dropped frame every 12.5 seconds or so.

Yeah, I don't know.  You would have to ask the mplayer/mencoder people.

> It would also seem that V4L doesn't actually discard any frames, but still
> passes them on to mplayer/mencoder, because mencoder shows an encoding fps
> of 30.04 (and it will skip a frame every 12.5 seconds or so unless you pass
> it -noskip).
>
> Am I right about all this?

Again, this would be an mplayer/mencoder thing.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com
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