Sound quality from DVD movies?

The answer is complex. Read http://en.wikipedia.org/wiki/DVD-Video#Audio_data

Quote:

Originally Posted by Perplexed 

Let's say I wanted the Inception soundtrack - would the sound quality from a DVD of the movie be the same / worse / better than a CD of the OST I purchased from, say, Amazon. What sort of technical specs would it have, and could I rip it / convert it?

 

Please also compare Blu-ray vs. DVD and Blu-ray vs. CD in terms of *sound quality only*

 

Thanks :)

The first thing I'd ask myself is if the mastering is the same, the mastering on the CD version is relatively average, far from stellar, I'm not aware of any other mastering though, and I don't have the BR nor the DVD.

Quote:

Originally Posted by Perplexed 
What are you inclined to think? If you hated the film but loved the score and I offered you a DVD of the movie or a CD of the soundtrack at the same price, which would you take?

You can put better quality of sound on a DVD then a CD, but as most music players are CD players, you would not sell as many disk if you sold music on DVDs.
 

If you want the soundtrack the DVD and Bluray of the film would have the final mix down of the audio including dialogue, sfx, and edits to the music. The CD would be your only access to the clean music tracks.

As far as technical aspects most video DVDs are encoded with Dolby Digital at 48khz @ 192kbs and it's a 5 channel compressed multichannel format. The thing about mastering video DVDs is that you always have to consider the max bit rate that the disks will accept for both multiple audio streams as well as the video. The audio pretty much has to be compressed to fit in different languages and multiple channels for playback along with the video. The compression used is very good, but it is a compressed format. 

With Bluray the technical specs are much higher, but I'm not sure what the standard encoding for disks are. Theoretically there is a much larger "bit budget" allowing for less compression and better audio quality. A quick look at the Inception Bluray online says that the audio is:

It's good example of how mastering a video DVD or Bluray in reality can require multiple audio tracks that can effect the actual use of the technically superior medium. I'm sure you could rip the soundtrack, but how are you going to deal with the 5.1 channels?

The DVD/Bluray is mixed in 5.1 and is incorporated into the movie environment as stated above. It is almost impossible to extract a pure "stereo" track from the movie without some corruption from movie effects (dialog, effects, volume changes, ect). You will need to rip the movie to a different file format for editing which almost always degrades/alter the audio tracks. Also you will require a good Video Editor to extract the soundtracks which will increase the cost. It's easier to buy the CD to get clean sound.

The mastering and even mix of some of the songs are different on the actual movie.  Will be impossible to get the soundtrack.  I've compared some games' music directly ripped and their soundtracks, and some of the masterings are different, but it depends from game to game.  There will usually be gray area for things like this.