bktr and Interlacing

Jacob Meuser jakemsr at jakemsr.com
Sun Apr 10 14:04:23 PDT 2005

On Sun, Apr 10, 2005 at 02:39:00PM +0100, Mark Dixon wrote:
> Hi,
> As I'm without a TV at the moment, I decided to plug my XBox into my TV card 
> (via bktr driver) and attempt to play the brilliant Burnout 3 via my monitor 
> and mplayer. Unfortunately, as soon as things get busy (as they inevitably do 
> in this game), the screen started to show signs of interlacing all over the 
> place, and as you can imagine, when driving into oncoming traffic at 200mph, 
> interlacing is not very helpful. 
> I had a quick look at the source and can't see any obvious interlace controls 
> - although there is one slightly worrying comment:
> /*
> * XXX NOTE (Luigi):
> * currently we only support 3 capture modes: odd only, even only,
> * odd+evgen interlaced (odd field first). A fourth mode (non interlaced,
> * either even OR odd) could provide 60 (50 for PAL) pictures per
> * second, but it would require this routine to toggle the desired frame
> * each time, and one more different DMA program for the Bt848.
> * As a consequence, this fourth mode is currently unsupported.
> */
> Does anyone know if there is a simple switch that needs setting somewhere to 
> make the card not do this, or if its simply a performance problem with 
> something (my computer, mplayer, bktr driver) not being able to keep up with 
> the amount of activity the XBox is throwing at the screen.

yes, you can get only only odd or only even fields, but I don't know
if this is supported from within mplayer.

you have to specify the right flags for the METEOSETGEO ioctl:

	geomet.oformat = METEOR_GEO_YUV_422 | METEOR_GEO_ODD_ONLY;

BTW, if you want a simpler way to view video from bktr, you could
try something I wrote -> http://www.jakemsr.com/bsdav/bktrplay.c.
there's a manpage too -> http://www.jakemsr.com/bsdav/bktrplay.1.

<jakemsr at jakemsr.com>

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