Wavy color background

[KLAU]

Hi, can someone help me to fix my problem.
I am using a PII 260Mhz, 6/15 GB hard drives, Matrox Rainbow Runner capture card with my G200 Matrox Video card, 128 Mb ram.
I have been using Tmpgenc encoder to make SVCD (captured from my VHS tape )to play on my standalone DVD machine. So far, the quality is very nice, much better than VCD.
However, there is a problem that has been bugging me. Whenever, there is a color background ( mostly red ) on the screen , I noticed there is some kind of wavy effect on the red background, the redder it is, the more wavy kind of effect I am getting.
The format I capture in Matrox is high quality, 704x480 MJPEG, NTSC. In Tmpgenc, I am using interlaced, field B, 480x480, VBR, Mpeg2, SVCD format.
Can any one help me on this, I am really desperate. It is really bugging me because everything turns out right except this.
I have been trying different options in Tmpgenc, still could not fix it.

[Dr Mordrid]

You're seeing a pixelization in the background caused by transcoding MJPeg to MPEG. This happens mostly in shaded, red and other areas where the MPEG encoder trips up over the different color reduction (quantization) methods used in the two codecs.

The fix: capture in uncompressed YUY2 video, encoded with the HuffYUV lossless encoder, and encode THAT to MPEG. Pure source = higher quality.

This gives great results, but your system is way too light on CPU horsepower to pull it off. Think in terms of a CeleronII, PIII or Athlon of about 600+ mhz.

Alternatively you can minimize them by lying to TMPGEnc (naw...he didn't say that did he? YES, HE DID!!).

A similar problem occurs with DV video being encoded to MPEG. The reasons are too long to list, but the fix for DV is to enter the TMPGEnc Options/Global Settings/General page (for ver. 12a. It's the Environment page in later versions) and checking the box labeled "Interpolate 4:1:1 YUV data to 4:4:4". TMPGEnc is one of very few MPEG encoders with this option.

Even though this setting is for DV it sometimes helps with MJPeg as well. SOMETIMES. No guarantees.

Dr. Mordrid


[This message has been edited by Dr Mordrid (edited 28 April 2001).]