Need help with S-video conversion to TV and mame

[oldie]

Hi.  Many moons ago I was active on this forum under a different username that I cannot recall.  I hope people are still as wise and helpful as before!

My cab has been dead for years and years, but I've started to bring it back to life.  I was given PC hardware that includes an evga GT 710 video card that has hdmi, hdi, and vga outputs.  My tv accepts s-video as input.  I purchased this video converter from vga to s-video: https://www.startech.com/en-eu/audio-video-products/vga2vid.  I have set it to NTSC and underscan.  When in windows 10, I noticed that the top of the screen on my tv was out of sorts whereas the rest of my screen seemed fine.  Changing resolutions in windows to something like 800x600 seemed to clear that up.  However, my desktop was not fully fitting into my TV display (it was too wide, and maybe too tall).  Then, after starting mspacman in mame, I see oddities at the top of my screen as in the attachment.  Note how the score area is just all goofed up, wrong font, wrong font size, somewhat mirrored.

I am at a loss and have no idea what to even search for to help me resolve this issue.  I am aware that converting from VGA to S-video is not ideal, but I really don't know a way around that issue given the inputs to my TV.

I would appreciate any pointers.

Thank you very much.

[oldie]

This issue went away when I changed the resolution on windows.

[danny_galaga]

Glad we could help 😄

Seriously though, thanks for posting how you fixed it. That might help someone else one day 🙂

[Zebidee]

The Startech device page you linked contains some important information in 2 of the the comments, though they slightly contradict each other:

- "VGA2VID accepts VGA input up to 1600x1200 resolution and outputs S-Video or Composite at 640x480."

- "The VGA2VID supports PAL: 576i and NTSC: 480i. An interlaced signal draws half a frame (called a field) at a time. NTSC 480i supports a frame rate of 30 fps. The field rate is 60 Hz. The PAL standard of 576i supports a 50 Hz field rate, and the frame rate is 25fps."

This means the device outputs video in a fixed mode (either NTSC or PAL). Everything will be squeezed/stretched to fit this mode. For best results, you should choose a desktop mode to suit. If you are using an NTSC TV (USA), then choose a 480i video mode for desktop. Despite the top comment above, you should try 720x480i as this is actually the NTSC standard, not 640x480. Have a play and see what looks right on your TV.

You should also consider restricting MAME to output for this video mode only. However, you probably won't even have a 720x480 or 640x480 mode available without special drivers/software. Unfortunately, CRT_emudriver won't work with nvidia cards like yours. Some people use CRU instead, but it doesn't have all the cool features as Groovymame/crt_emudriver. Luckily compatible video cards are cheap, so I'll leave that to you. Check the Groovymame forum branch for more info.