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View Full Version : How to Play "interlaced videos" on TV via TV-out of PC graphic card ?


aleste81
10th November 2007, 19:49
Can a PC with TV-out emulate a DVD player ?

I have a 720x576 interlaced video, and a interlaced TV.

If I play the interlaced video on the interlaced TV via a DVD player, obviously the 576 interlaced lines will be displayed correctly on their 576 interlaced phosphored places on my interlaced TV.

BUT if I play the interlaced video on the interlaced TV via the TV-out RCA plug of the PC, I feel there is very few chances that the 576 interlaced lines of the original interlaced video will be displayed correctly on their 576 interlaced phosphored places on my interlaced TV (since the video is stretched by the PC).
And I get "ghosting" effect.

Is there a trick to emulate a DVD player from a PC ?

2Bdecided
16th November 2007, 12:29
There is a world of pain involved in trying to get this to work. The main problem you have is that TVs run at 50Hz, and PC displays and graphics cards normally don't. The other major problem is that standard TV-out functions don't attempt to perform a pixel perfect output of the display, so you can't get those 576 lines out properly.

I've read threads discussing this before (not on this forum) - a google for powerstrip 50Hz RGB etc might help. Also try searching uk.tech.broadcast, uk.tech.digital-tv and similar groups. People also battle this with Windows Media Centre, so browsing UK MCE forums might help.

I don't think I've heard of people making this work properly via a standard TV out. The closest they get is bobbing the content, forcing the PC to 50Hz, and hoping there's not too much scaling.

You can do it properly without scaling via the VGA output of some graphics cards with a VGA>RGB adapter into a SCART plug. Read about Powerstrip for more info.

Hope this helps.

Cheers,
David.

reepa
16th November 2007, 13:32
You don't need Powerstrip if you have an NVidia video card. NVidia's drivers allow you to adjust timing parameters (Advanced timing under Screen resolutions & refresh rates). You can generate all kinds of wacky video modes such as 2048x1152 @ 100Hz interlaced. There is a predefined 625-line mode, 720x576 @ 50Hz interlaced, which you could feed directly to a TV with an RGB scart socket (you need a simple HD-15 -> SCART adapter).

I'd love to hear how to get what you want working using the tv-out of a video card. Standard definition tv-out seems to be very neglected.

edit: Seems like NVidia cards/drivers don't support composite sync so you need some electronics instead of just a simple adapter.

Didée
17th November 2007, 17:30
That's why I still love my DH Matrox for feeding a SD television. No tricking-around with 3rd-party tools, no need to build electronic circuits.
Just connect to the TV. Everything perfect.

SeeMoreDigital
21st November 2007, 10:40
That's why I still love my DH Matrox for feeding a SD television. No tricking-around with 3rd-party tools, no need to build electronic circuits.
Just connect to the TV. Everything perfect.This is why I was so fond of my Sigma Xcard too!

You'd think the graphics card manufacturers would have recognised the need to provide good quality interlaced support for TV connected users many years ago :(