MPEG1 versus MPEG2 Question

[humanbomb]

Hi,

I have an avi at 640x256, 700Mb, 90minutes, so the quality is quite good.

I have encoded it using TMPGEnc as MPEG2 at just over 5000 with resolution of 352x240. I also clipped it 20 frames left & 20 frames right because I hate those tiny letterbox films. The first time I just used TMPGEnc's High Quality setting. The picture quality was dreadful, noisy with annoying horizontal lines.

The second time I encoded it with the same settings but this time used TMPGEnc's Very High Quality setting in addition to using the Noise Reduction setting. After 12 hours of encoding the picture quality was still noisy with annoying horizontal lines.

Note, that I played the DVD on two players - one Panasonic stand alone & the other a cheap Chinese player I bought when living over there.

OK, the third time I encoded I again used TMPGEnc, but this time used MPEG1 2 pass Variable Bitrate at an average of 5000 as well as a resolution of 704x480 instead of 352x240. I again clipped it the same as before, used High Quality, & DID NOT use any noise reduction. The resulting file was half the size of the previous two MPEG2 encodings yet the quality was excellent, with little or no noise & no annoying horizontal lines.

I don't understand how this is possible. I have noticed this before on other projects that MPEG1 'seems' to look better than MPEG2. On this ocasion would me using a resolution of 704x480 instead of 352x240 be the reason?

thanx

[LT. Columbo]

"After 12 hours of encoding the picture quality was still noisy with annoying horizontal lines."

next time just do a sample of the video to see how it looks, using the source range feature. you can do any length you want, at any point in the file. better than having to wait 12 hrs just to experiment with settings.

with the larger esolution you will get a better quality result.

[jonallen]

First of all, yes, your resolution is causing your problem. You're halving your frame size, of course it's going to look awful when you blow it up to the same size with effectively 1/4 the # of pixels of the original.

[tigerman8u]

"I have an avi at 640x256" with that resolution I would go for full D1 (720x480). Resolution by it self won't make the quality better or worse. You have to take into account the quality of the source and the video bitrate etc.