[mythtv-users] Having problems / Need info on BOB Deinterlacing

[Steve Hodge]

On 6/3/06, James Buckley <james at logicland.co.uk> wrote:
> So, how do I know if linear blend is producing 25 or 50 fps.

Linear blend is 25 frames per second - only bob doubles the framerate.

> Basically, I want to emulate what my TV does. With Sky, the pictures is
> perfect (at least to my eye), from another thread I'm running apparently sky
> does no deinterlacing, and merely passes an interlaced stream (which would
> have 50 "half frames" right) to the TV. The TV then deals with it how it
> likes (either by deinterlacing the image or just displaying it).

Your TV is doing the deinterlacing. So your options are to feed the TV
and interlaced signal and let it deinterlace or try to figure out how
it's deinterlacing and try to do the same. For that second option, all
you can really do is try each of the deinterlace options and see which
looks the best. If none of them are up to standard then you have to
take the first option.

> I want the same setup; only my problem is it's hard for me to have an
> interlaced DVI connection. So the solution must be by deinterlacing the
> stream before it's sent). OK, so what refresh rate should I have my TV set
> to (I can control this using a ModeLine, I can get as close as 50.01Hz), and
> what deinterlacing should I use (don't worry about computing power
> limitations, my 64 3500+ should cope with at least SDTV). If I am to use
> BOB, I don't (if I can help it), want any "BOBing", ie. Jumping.

You want to use a refresh rate that is an multiple of 50Hz, so 50 or
100 should work.

Have you tried the "kernel" deinterlacer in MythTV? You shouldn't get
the flickering of the OSD you get with bob. But if 25fps is too slow
for you then you'll have to use bob or try to get an interlaced signal
to your TV.

Steve