MAMEWorld Forums - EmuChat - Re: Help with creating TRS-80 COCO screenshots,

> I've been trying to create screenshots for a number of games for the TRS-80 CoCo to
> post to Mobygames. Unfortunately, they only accept screenshots that are 16 colors (4
> bit). Try as I might, I can find no way to make MAME produce screenshots or display
> other than 24 bit (lots o' colors). Help would be appreciated as to how I can get
> MAME to display like this, or at least produce screenshots like this using the TRS
> Color Computer

Assuming you're using Windows (no idea about Mac/Linux), IrfanView can batch-convert images to 16 colors - just make sure to disable dithering first, in case it makes a grainy mess of the files. Hopefully Mobygames isn't also forcing a certain palette order, as that would be a PITA.

While it would be nice if MAME could preserve color palettes when taking screenshots, in most drivers it is simply not possible, or would be very tedious to set up per driver for the machines which actually do only output 256 colors or less and never stray from that amount (e.g. MAME's PC drivers, which can go from 16 color EGA right up to 32-bit RGBA depending on the video card installed).

On the higher end of the scale, the PNG format doesn't support bit depths between 8 and 24 either, and if artwork, bezels, LEDs etc. are part of the screenshot it would be forced to use 24-bit anyway regardless of the screen output.