ATI MMC 8.7 - MPEG-2 (DVD) aspect ratio correction

[erratic]

Aspect ratio freaks like me should read this. It's meant for people who capture directly to MPEG-2 with an ATI/Hercules (AIW) Radeon card and use those MPEG-2 files for DVD (or SVCD) authoring.

[lordsmurf]

I wouldn't put too much "alarmist" spin on this.

It bascially says the newest MMC 8.7 causes problems for PAL users using 720x576 MPEG-2. They should customize it for 704x576 through registry hacks.

And then NTSC SVCD MPEG-2 is affected too.

All other resolutions seem to be fine, notably the Half D1 that many people use anyway, coming from traditional analog sources.

To me this just says "don't use MMC 8.7" making MMC 8.5 the max one suggested since 8.6 also had errors in MPEG-1 and other timer and dropped-frames issues on some systems.

[erratic]

It's not just MMC 8.7. Older versions capture 720x576 wrong as well. 720x576 has never been correct with any version of MMC I have used. The correct full PAL resolution for any Radeon card is 704x576 (whether it's MPEG-2 or AVI). I capture with VirtualDubMod most of the time and the resolution I choose is 704x576. It has nothing to do with the capture program, it's a driver thing. Very few tv capture cards get 720x576 right and that goes for 720x480 NTSC as well.

Two interesting Doom9 threads:
http://forum.doom9.org/showthread.php?&threadid=64635
http://forum.doom9.org/showthread.php?&threadid=32604

[lordsmurf]

I've always been against 720x480 for similar reasons. The 720 lines doesn't cooperate well with a tv set. It may be higher res, but there are linear artifacts on slight curves, something not seen with 352 or 704.

[erratic]

Yes, both 704 and 352 are correct for PAL. I have tested this myself with a test pattern on my tv. I assume this is true for NTSC as well.

720 (DVD) and 480 (SVCD) are a little stretched on a tv.

If you're using a Radeon card for SVCD authoring there are two ways to get the aspect ratio correct, but you have to capture to AVI first. It's impossible if you capture directly to SVCD MPEG-2 with ATI MMC's SVCD template, unless you want to resize and re-encode.

The following examples are for PAL, but I assume they apply to NTSC as well if you replace 576 with 480.

Option #1
Capture 704x576. Add black bars (8 pixels wide) left and right to make it 720x576. Resize to 480x576 for SVCD.
Option #2
Capture 468x576. Add black bars (6 pixels wide) to make it 480x576. No resizing necessary. I don't think it's possible to capture 468x576 with ATI MMC. You need another AVI capture program for that.