Cleaning up MPEG1 files. Removing green blocks

[steverae]

I have a number of VCD's which play fine on my DVD player (Pioneer DV350).

However, i switched my output to RGB from for a much better picture and found that on black scenes, i.e. the start of say STAR WARS, the black screen has lots of dark green squares all over it. Which go away when the screen is playing the film, they only appear when viewing a black screen on RGB output. When viewed on normal setting it's fine, just not quite as sharp.

The VCD was encoded from a DIVX downloaded from the internet.

My question is, can i reencode the mpeg file with different filters etc to correct this problem, or do i need to download the movie again and reencode from the divx, if so, what settings do i need to apply to fix this problem. I use TMPGENC for encoding

Thanx in advance.

[DJRumpy]

Your luminance scale is wrong. It was squashed somewhere during the conversion process, or stretched to PC scale (255). You would need to describe how you went from source, to final output.

[steverae]

I simply opened the divx file in tmpgenc, changed the video and audio bitrates accordingly, then hit start. I did nothing with the advanced settings at all, left them all as standard.

I know there are two settings, Output YUV data as CCIR601 and Soften block noise. Should these make any difference. ?

[DJRumpy]

The DivX file itself is probably the source of the problem then. You can try darkening the Luminance scale by 15, which will fade those dark green areas to black. You will have to do it in VirtualDub, or AVISynth, as TMPGenc has no filter for that sort of modification. You can use either of the above to modify the AVI, and frameserve it to TMPGenc.

[steverae]

Cheers for the info m8


I've vdub quite a lot for converting 23.976 movies to pal, so i'll have a tinker with the settings and let you know the result.