App to check DVD compression?

[Beater]

Uhm, i need a way (perhaps an app) to check the compression of a dvd-r.
The thing is that i´ve tried to backup a DVD to a dvd-r. With DVD Shrink i can choose the compression of the movie, extras, etc.
But i have also tried to backup a DVD with DVD2One, but there I only have the possibility to backup the whole disc och just the actual movie.

So I wanna check the compression that DVD2One have done, is it possible in any way to do that?

I hope you guys understand my question (because of my bad spelling)

Thanx in advance.

[Dimmer]

If you made a backup of the entire DVD, just compare the size of the original disc with the size of DVD-R, this would give you the compression ratio. For example, if your original DVD is 5600Mb and your compressed movie on DVD-R is 4480Mb, then you have 4480/5600*100 = 80% compression.

[Matthew]

I dont agree with that dimmer as it is the video stream you are compressing. So the relevant compression rate is (size of new video stream)/(size of old video stream). Including audio streams, etc distorts the figure.

I know you can use DVDtoolbox (old free version, it's now payware and called dvdfab) to get the size of a video stream without extracting it out, but it isn't especially quick.

[Dimmer]

I stand corrected - you're absolutely right, only video is compressed but not audio. I can't think of any (free) software that would just give you size of the video streams. Of course, you can demux all the video streams that's been compressed from all the VOB files on the original DVD and on the backup, and then compare the size. TMGEnc would do the job, although it might take quite a bit of time.

[Kedirekin]

Load the DVD2One output into DVDShrink. DVDShrink tells you the size of the video stream (the values next to 'no compression' are what you want). You can then compare the size from the original DVD and the size from DVD2One output to find how much DVD2One compressed it.

The values after quick analysis are pretty close (I'd guess within 1 or 2%), but if you want really accurate sizes, I think you'll need to do a deep analysis.

[Beater]

Originally posted by Kedirekin
Load the DVD2One output into DVDShrink. DVDShrink tells you the size of the video stream (the values next to 'no compression' are what you want). You can then compare the size from the original DVD and the size from DVD2One output to find how much DVD2One compressed it.

The values after quick analysis are pretty close (I'd guess within 1 or 2%), but if you want really accurate sizes, I think you'll need to do a deep analysis.

I have alreday done this, and it works ok. It´s just that that it would have been easier if I could check it with a little app. I´m actully supriesed that a app like that doesn´t exist!

Well, thanx anyway. :)

[Kedirekin]

On further consideration, I don't think a little app like that is possible.

If you load up a DVD to find it's compression, it doesn't have anything to compare to. There is no derivable benchmark to compare against.

It's like saying - how much smaller is a duck?

[ronnylov]

There is a program called BitrateViewer which can scan the video stream and tell you the average and maximum bitrate used as well as the quantization level. The lower average bitrate used the more it is compressed.