Frage von soahC:
Hi together,
hab mal wieder an issue. Why does an AVI or DivX video with 700MB burn to DVD when suddenly 4GB? If you have something to burn to DVD (ie video-DVD) will it Mpeg2 compressed. If so if it does not tend to be smaller rather than larger? And how can a video-only MPEG Compression suddenly be so inflated? Where should the extra information come from?
Have never really understood. I hope someone can help me ...
Oh yeah, I burn with Nero7
Antwort von Markus73:
hab mal wieder an issue. Why does an AVI or DivX video with 700MB burn to DVD when suddenly 4GB? If you have something to burn to DVD (ie video-DVD) will it Mpeg2 compressed. Right, and MPEG2 compressed significantly weaker than the newer DIVX or MPEG4 codecs, which are Usin an AVI file to hide. Hence the larger file.
Gruß,
Markus
Antwort von soahC:
Aha. The example I ever knew not.
But it is not actually the encoder no preference what codec it just compressed? For the video is just a video, and was sometime earlier times (such as DIVX) "way" is compressed but anyway can not expect more back.
Times I ask: I have 3 files as a video which I would like to burn. All of them have between 600 and 700 MB. The DVD would be for an already "full" in excellent quality. Do I add a 2nd file added, the quality is only "medium". But changing the quality of the files is really still, or Nero shows the only way to?
Antwort von Mylenium:
But it is not actually the encoder no preference what codec it just compressed? No, not really. From colorspace conversion to Neukomprimierung happening much more certain and codecs are structurally quite similar, so that individual steps can be omitted.
But changing the quality of the files is really still, or Nero shows the only way to? Yes, of course. That needs to be visually but not necessarily noticeable.
Mylenium
Antwort von Tobias1708:
@ Mylenium:
The first part, I do not understand! The video should always be smaller the more often I compress. Regardless with whatever codec. One of uncompressed to Avi, then Divx, Mpeg then ... how can the video because Grow? When will compress but no new information about this effect, but only the go!
Example: In the raw material has a subtle gradient, or a history of gray to black. Eventually, after 2 or 3 times compress remains only remaining gray, or in grainy mud. This happens because the very fine details zusammengequetscht transition (ie compressed).
With a further Kompriemierung the original course but never restored. Why there will be greater? An increase in the size means more to me Infromationen or new information. It happens but it does not?
Sorry if I pester, but I would now like to understand ...
Antwort von Mylenium:
The first part, I do not understand! The video should always be smaller the more often I compress. Wrong. Compression works only within the limits of the algorithm and can never break its rules. Something like how negative binary values, there is not time now, but you wegrechnen, the algorithm was evaluated as unimportant or redundant recognizes. In addition, we are talking here not about pure Binärkompression, but visual-perceptual.
The MPEG algorithm searches for edges and consistent color and translates them into block patterns, no more, no less. This can be as MPEG 4 and DivX adaptive and very fine and therefore very efficient, but it may as synonymous with MPEG-II with a fixed grid and its very large blocks and therefore not as efficient.
That explains so synonymous that increasing the data rates: The structure and content of the image of the data must be s.bestimmte fixed pattern and can hold only within very small tolerances vary.
For MPEG-II (DVD) means that at least all 12 frames (GOP) an I-frame (quasi-JPEG) with only minor compression and must occur within this 12-frame 2 difference images (B-frames), from which in turn the P frames are derived. The grid is based on blocks of 32x32 pixels, the smallest block can never be smaller than 8x8 pixels. This must have fine elements with a relatively large number of coded data.
In MPEG-4 is quite different. There is neither a fixed GOP size nor a fixed grid and the smallest blocks, up to 2x2 pixels small. The whole system works and can therefore adaptiv is much more efficient compression. It may therefore well be that parts of image that extends over several seconds are not modified, only once s.Anfang analyzed and coded, whereas in MPEG-II, which forced all the frames on some's new would happen.
Mylenium
Antwort von Markus:
One of uncompressed to Avi, then Divx, Mpeg then ... To AVI format see synonymous
Magix can not read AVI. DivX is synonymous in the AVI container, as well as MPEG2 or uncompressed.
Perhaps the issue easier to understand, if you instead of a compression of a format conversion expect. Stark simply looks like this:
Suppose that a DivX video is compared to the uncompressed template by a factor of 150 data-reduced, ie the new file is 150x smaller than the template. If the DivX video into a DVD-compliant MPEG2 file will be converted, then (not quite correctly, but for clarification useful display) the video first on its original size and then interpolated with the new targets newly compressed. From 1:150 will only 1:1 and then 1h30. The MPEG2 file is larger than the original DivX video.
Makes sense, such outward Herkompressionen and certainly not because of any format conversion loses the video image information to each other to new De-/Kompressionsschritt artifacts.
Antwort von Andreas_Kiel:
The video should always be smaller the more often I compress. Nope, if you ever would use the same codec, it would be after each run even bigger.
The reason: smooth surfaces are easily compressible, fine structures are not. That you'll see in a picture from the very good DSLR, take to the sky again and then leaves.
Each course creates compression artifacts, which in turn is "small changes" represent, and which can be bad compress ... New artifacts and even more size.
BG, Andreas
