H.263 vs. Mpeg quantization

[cogd115]

I understand that the two are differentiaed in terms of sharpness of images. But do they cause or affect moving background in different ways, as well?

I have done two encodings of The Terminator, one with mpeg and the other with h.263. I have found that the one with h.263 produced less of moving background. However, this can be biased as I used different b-frames, mpeg with max b-frame of 2 while h.263 with max b-frame of 1. Being a newbie, I lack knowledge to extrapolate the whole thing.

So, my question obviously is: why the difference in moving background? Is that caused by quantization or by the change in b-frame setting? Or, is this just an optical illusion on my part? :D

Thanks in advance..

[sh0dan]

Since MPEG is more sensitive to high-frequency (detailed) areas, it is very likely to cause more moving backgrounds, as these parts are typically out-of-focus.

That is my experience anyway. I tend to be more biased against MPEG, as it produces much sharper images, but the trails and moving blocks in MPEG is holding me a bit back.
So I usually try encoding an MPEG and an H.263 with VHQ 0, and decide which one to use, and do a full VHQ 4.

[LigH]

Originally posted by sh0dan
So I usually try encoding an MPEG and an H.263 with VHQ 0, and decide which one to use, and do a full VHQ 4.

This is obviously the long but more exact way...

If you just need a "thumb rule": 1-CD copies with a little smaller image dimensions usually look better with H.263, for MPEG you shall aim for more bitrate and therefore rather for 2..3-CD copies. A bitrate range is hard to tell; in my opinion, up to 0.25 bits per pixel and frame is rather low for XviD, above 0.3 bppf is rather high. But this is subjective and depends on your measure of quality: Your eyes tell you your own truth.

[DarkDudae]

I allways do a compressibility test, if the obtained values for my selected settings (video size and resolution) are higher than 70%, I use MPEG, in other case, I use H.263.

Regards

[Koepi]

I prefer MPEG in all cases if it's somehow doable - mpeg doesn't show block artefacts as fast as i.e. HVS GOOD or h263 matrices. But that's maybe not what you wanted to hear :)

Best regards
Koepi

[cogd115]

So, I take that there is no empirically tested and confirmed conclusion. :D Or, Koepi sounds very convincing. :D I get the drift, though.. Thanks guys..

[Enigmax]

I also prefer to use MPEG. H.263 seems to me dirtier results.
I always look for a compressibility above 70 %.

Greetings

[Phanton_13]

I prefer MPEG for real content an H263 for anime content, but in some rare cases I use MPEG for anime content.