Avidemux offers 2-4 kinds of mp4 ASP, help distinguish!

[MovingParts]

Hello,

I know there is Mpeg4 AVC (x264) which is the preferred one, but if I choose Mpeg4-ASP there are several options:

A) Mpeg4 ASP (ff)
includes: a.1 h.263 and a.2 mpeg (can be found via "cofigure -> Quantisation -> quantisation type")

B) Mpeg4 ASP (xvid4)
includes: a.1 h.263 and a.2 mpeg (can be found via "cofigure -> Quantisation -> quantisation type")

Is one of these ITU-T H.263 / MPEG-4 ASP Video: DivX, Xvid, Adobe Flash ?

When people say, "if your PC's CPU is to slow for playback, use the old mpeg4 instead of h.264", do they mean A or B and do they mean h.263 or mpeg?

[jagabo]

1) MPEG 4 part 2 = MPEG4 ASP = Xvid = Divx
2) MPEG 4 part 10 = h.264 = AVC = x264

If your PC is too slow use #1. A and B are two different implementations of #1.

Quantization type is a feature within the codecs. I discussed that in your other thread:
https://forum.videohelp.com/threads/374169-Avidemux-questions-quantisation-vs-quantisat...=1#post2410499

[MovingParts]

OK, A and B are different implementations of 1, but what is the difference between a1, a2 and b1 and b2.

No, in the other thread it was about whether to use "constant quantisation" or "same as source quantisation" (which can be found in: Avidemux-> Video Output -> configure -> userinterface (first tab, it is called "Benutzerschnittstelle" in German) -> coding modus). the choice of h.263 or mpeg2 can be done under the third tab, in the other thread I was asking about the first tab).

If you want to say, that h.263 and mpeg are two quantisation types of mpeg4-part2 divx/xvid then ok. Does that just mean they are two different ways of executing what one has picked previously under "constant quant." and "same as..."?

Do you have Avidemux installed?

THE SECOND AND THIRD PICTURE COMES, WHEN YOU CLICK ON CONFIGURE IN THE FIRST WINDOW.

[jagabo]

No, in the other thread it was about whether to use "constant quantisation" or "same as source quantisation" (which can be found in: Avidemux-> Video Output -> configure -> userinterface

No. You started asking about Quantization Type and I answered that question.

First there is "quantisation type h.263 or mpeg". I get confused with the codec and the format, what would "Mpeg quantisation be there".

The quantization matrix controls what frequencies are deprecated in the DCT domain. The mpeg matrix gives sharper results but requires higher bitrate. The h.263 matrix gives less sharp results but does better at lower bitrates.

Many encoders allow you to use others matrices too.

https://en.wikipedia.org/wiki/Quantization_matrix#Quantization_matrices

This has nothing to do with the the Target Quantizer or Constant Quantizer setting that some encoders support. And I already covered for you too:

https://forum.videohelp.com/threads/374169-Avidemux-questions-quantisation-vs-quantisat...=1#post2410647

The smaller the quantizer you select the higher the quality, and the larger the size, of the resulting video. Think of the quantizer as specifying how much detail you want to throw away. The more detail you throw away the smaller the file will be but it will look worse too.

[MovingParts]

Thanks!