Bit Rates and DVD Shrink Deep Analysis

vbimport

#1

After reading the guide in this forum section on ‘the best transcoding program’, I got the impression that when you use deep analysis with Shrink, the compression using a variable bit rate algorithm but without the deep analysis, it is a constant bit rate. Is this correct? If so, of course it depends on the original dvd bitrate as well, but I expect you would find more scenes with pixelation and other compression artifacts after using deep analysis than if not. Without deep analysis, the overall picture quality would be lower but at the same time, you wouldn’t have to deal with random points in the movie where artifacts show up.

This post was inspired by my recent burning of Family Guy DVDs using deep analysis. Obviously with animation, it is much easier to detect artifacts in the video. I figure just using a CBR may actually be better for the burn.


#2

Just a followup to the post to clarify my position and perhaps my opinion. Shrink without deep analysis ie. encoding with a CBR is like converting the DVD to a .avi format. It is just lowering the quality of the DVD minus the artifacts from VBR.


#3

deep analysis or not, vbr is always used with dvdshrink (and as far as i know, any transcoder). i find that artifacting/pixelation is much less noticeable when dealing with cartoons that have pretty much solid colors. artifacting usually occurs in scenes where colors mix together, which rarely happens with a cartoon like family guy.


#4

DVD Shrink does not have ANY impact on bitrate… since it isn’t re-encoding the data at all. It’s only dealing with the transform data, which has a minimal impact on “bitrate”, per se.

Deep Analysis is explained in detail in other threads, I won’t rehash it here (because I’d do a poor job).


#5

So then maybe all the pixelation and artifacts I was seeing in my Family Guy DVD was simply due to Shrink choking during the compression stage? Is it highly recommended to burn the whole DVD to the HD with Decrypter before compressing with Shrink?


#6

That won’t make any difference as far as quality is concerned. If you’re unhappy with the quality of DVD Shrink then you should consider switching to a different transcoder (althought they’re all pretty much the same in my opinion) or to the DVD Rebuilder method.


#7

Maybe I will try Rebuilder. But from reading threads on this program it seems much more complicated to work than DVDShrink. Any useful Rebuilder-for-dummies guides out there?


#8

Rebuilder is super-duper easy… once you’ve set it up.

Setting it up is “easier” now, but still requires an advanced degree.


The reason you get pixelation with Shrink and artifacts in things like cartoons… is that it essentially compresses the living daylights out of the transform data - which is quite a bit of the movie, to be sure… the problem with cartoons is that they are SO SHARP. Lots of abrupt color changes with no transitions.


#9

@bomber18

have you used maximum sharpness to transcode with shrink?


#10

If I can Do it anyone Can:p The new Install package makes it a breeze, about the only thing to play with is the DVD RB command line to be sure you dont waste any room on DVD as well as VBR Bias and Quality Settings.


#11

Yeah actually it isn’t too bad, once your encoder is running properly… :wink: