Quality differences, other things being equal

[ojdidit]

I use DVD Shrink and the high quality settings when compressing and nearly always the result is identical to the original, at least on my equipment. But one disc in 15 or 20 will be of much lower quality. The latest example is " Born Into Brothels". Other movies that required an equal 53 to 54 % compression ( no example comes to mind) looked perfect. But BIB looks like it was quickee compressed, poor edges and itchy backgrounds.
Can this be caused by the use of different codecs by the studios on the original discs?

[setarip_old]

Hi!

Although I'm not familiar with that particular DVD, sometimes movies are intentionally shot to look other than "crystal clear", or "odd" in some other respect.

Two fairly recent releases that come to mind are:

"War of the Worlds" (Steven Spielberg version) - Intentional "graininess"

"The Aviator" (Martin Scorcese) - Intentional blue substituted for green, to simulate the deficiency of Technicolor film used in the 1940s

[ojdidit]

Hi set_a_rip

I agree that sometimes artistic choices are made. However I'm talking about an obvous difference in quality between the original and the copy and wondering if there's a difference in the 'density' of info per frame from movie to movie or something to that effect. I may not have made that point clear in my first post.

I'm trying to understand why two different movies of equal total size, 8.5 gig or thereabouts, can have different copy quality when being backed up with the exact same tools used the same way.

[setarip_old]

But BIB looks like it was quickee compressed, poor edges and itchy backgrounds.
Can this be caused by the use of different codecs by the studios on the original discs?This certainly sounded to me as if you were speaking about the original, purchased, commercial DVD ;>}

Be that as it may, every DVD is different - different durations, different amounts of action, different amounts of color, different resolutions, different bitrates, different types of audiotracks (Which don't normally get compressed) - all of which affect how good a compressed version will look at different rates of compression...

[ojdidit]

Having spent some time reading newbie forums and planning to do more of it, I'm seeing things like 'recode and encode'. Are they terms for separate ways to reduce originals to blank media?

I wouldn't mind spending the extra time on the occasional movie that doesn't compress well with Shrink. Can you reccomend an app that may give the quality I seek?

[setarip_old]

"DVD Rebuilder" is supposed to be the creme de la creme. There's an entire section of these forums devoted to it ;>}

[BSpielbauer]

I use DVD Shrink and the high quality settings when compressing and nearly always the result is identical to the original, at least on my equipment. But one disc in 15 or 20 will be of much lower quality. The latest example is " Born Into Brothels". Other movies that required an equal 53 to 54 % compression ( no example comes to mind) looked perfect. But BIB looks like it was quickee compressed, poor edges and itchy backgrounds.
Can this be caused by the use of different codecs by the studios on the original discs?

The fact is that certain "scenes" will also suffer more from compression than other types. As a quick example, it is well-known that fast moving action shots, those with "quick cuts" and "fast pans" will always come out looking worse than a slow, tranquil shot, or an unmoving shot of a landscape. Those who are viewing high definition material through DirecTV (which is using a lot of compression) can attest to that, especially if they have the ability to switch over to the same programming coming from an off-air feed, via an antenna. The same is true of DVD compression. So, a film with lots of "hurky jerky" camera shots, or lots of action involving quick camera cuts will look much worse than static, unmoving shots. Try to severely compress a film such as the recent western "Open Range" and you can experience both. Long, beautiful shots with a camera which is frozen, which can suffer a LOT of compression before you might notice. Then, later in the film, some sudden fast-cuts with the camera, which will show you how compression can suddenly make your pristine DVD backup look like a bad VHS transfer.

This is actually why many transfers of DVDs exhibit a wide variety of bitrate usage, throughout any film. Keep in mind that the original DVD was also using compression, and those who master these things, and perform the transfer, and the original authoring are very aware of this issue, and they sometimes have stretched things to the max already in a scene, so they can cram in just one more "making of" short subject, or one more "deleted scene."


-Bruce

[ojdidit]

@ setarip

thanks for the word on Rebuilder. I like that everything needed is freeware. And that there is a good guide available for setup and use.

[setarip_old]

thanks for the word on Rebuilder.As always, my pleasure ;>}