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Converting Bay Trail's VGA output to component PAL video?

Posted: Tue Apr 08, 2014 2:46 am
by jack_kelly
Hi there,

I'm hoping to use a Bay Trail system as a Windows 7 home theatre PC (Bay Trail borrows the integrated Intel HD Video processor from Ivy Bridge).

The slight snag is that we have an old CRT TV which only has analogue video inputs (S-Video / composite / component / RGB SCART).

My understanding is that passive cables are available which allow a VGA output to be connected to a RGB SCART video input on a TV (i.e. the red, green and blue signals are connected to the appropriate pins).

But this setup will only work if the graphics driver can be persuaded to deliver 576 interlaced at 25 frames per second (50 fields per second).

Does anyone know if Bay Trail can output 576i/25?

(edited to fix issue identified by washu below)

Re: Converting Bay Trail's VGA output to component PAL video

Posted: Tue Apr 08, 2014 8:55 am
by CA_Steve
Welcome to SPCR.

Don't know the specifics for Bay Trail. You might find the answer somewhere in here. And yes, there are passive converters for VGA to S-Video. Seems like every discrete video card I bought had one included (for a while).

Re: Converting Bay Trail's VGA output to component PAL video

Posted: Tue Apr 08, 2014 10:58 am
by jack_kelly
HI Steve,

Thanks loads for the reply; I'll check out that Intel site you linked to

Re: Converting Bay Trail's VGA output to component PAL video

Posted: Tue Apr 08, 2014 11:57 am
by washu
Component video is YPbPr, VGA is RGB. Just because component cables are commonly Red Green and Blue does not mean they carry RGB. Even if you can get 576 interlaced 25 fps out of VGA it still would not work unless the video system supports outputting YPbPr.

There are passive converters from VGA->S-Video and VGA->Component, but the video card has to support their use. You can't use them on just any card.

Re: Converting Bay Trail's VGA output to component PAL video

Posted: Tue Apr 08, 2014 12:00 pm
by jack_kelly
washu wrote:Component video is YPbPr, VGA is RGB.
Woops, sorry, you're quite right. Sorry. My TV can handle RGB so I need to go from a VGA connector to RGB SCART (but I still need a graphics driver which can output 576 interlaced at 25 frames per second)

Re: Converting Bay Trail's VGA output to component PAL video

Posted: Tue Apr 08, 2014 7:19 pm
by washu
jack_kelly wrote: Woops, sorry, you're quite right. Sorry. My TV can handle RGB so I need to go from a VGA connector to RGB SCART (but I still need a graphics driver which can output 576 interlaced at 25 frames per second)
For SCART you also need to give it composite sync. VGA is normally separate sync. Some video cards can do composite sync directly if set to do so, otherwise you will need an adapter that combines the sync signals. You can build one pretty easily if you are handy with electronics. I know pre-HD Intel graphics could do composite sync, but I don't know if the current ones can.

You should check out the program Powerstrip. It can set custom resolution/timings/etc. Your hardware has to support it, but it will often give you far more control.

Re: Converting Bay Trail's VGA output to component PAL video

Posted: Wed Apr 09, 2014 12:36 am
by Vicotnik
Messing around with analog signals is such a mess.. I would really look into getting my hands on a used LCD TV with HDMI input, or even an old TFT monitor with DVI. I recently built a "kitchen TV" out of an old HP TFT monitor (with built in speakers!) and a Raspberry Pi. Don't have to cost a lot.

Re: Converting Bay Trail's VGA output to component PAL video

Posted: Tue May 06, 2014 4:08 am
by jack_kelly
great stuff, thanks loads for the replies!