Hi,
In
this thread, I wrote:
Quote:
Originally Posted by Kat Manton
The MythTV/Linux system produces RGB, though I've still to sort out something which will generate proper mixed sync from the H/V sync. Given the number of standards I've got the system to do, I think that's going to end up with a microprocessor in it.
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It's been on my 'To Do' list for a while (where 'while' tends towards 'several years'.) It's possible to crudely combine the H and V sync emerging from the video card to produce something most TV sets recognise as 'sync' and lock to.
But now, I seem to have a little more incentive to 'do it properly'. The SECAM encoder needs mixed sync and mixed blanking as well as RGB video if I'm going to watch anything other than colour bars on a SECAM set. Got RGB, not got proper sync or blanking...
One idea I've had recently is inspired by the R. T. Russell test card generator.
Store sync and blanking data in ROM. Lock clock signal to sync from video card. Read out data from ROM, add to video signal or send to separate outputs as required. Doesn't need a DAC as it isn't producing video.
It keeps it simple, it can be configured for different standards (by generating the data with a C program on a PC then shoving it in an EPROM, perhaps), it doesn't require a microprocessor, it sounds like it could be cheap...
This is purely an idea at present, I haven't thought about it very much. "The Devil's in the details"; there's bound to be something interesting waiting to trip me up if I pursue this idea...
Regards, Kat