problems with DVD SHRINK and dts-es 6.1

[desaho]

has anyone else encountered a similar problem...i attempted to backup my copy of "House of the Dead" using DVD Shrink and after analysing the disc no 6.1 audio was available in the selection boxes. dts 5.1 was available however. Is DVD Shrink not capable of displaying the 6.1 or is it a matter of not being able to encode it.

any help would be appreciated

[turk690]

If this is like Dolby Digital, then everything is fine. That is, there are really no 6.1 discrete channels in the audio stream; what we have is still 5.1, which DVDShrink identifies as. There are 5 discrete channels: Lf, C, Rf,Ls, & Rs, and a low-frequency channel (the .1). The 6th channel is the back surround channel (or the rear center channel as some say Cs) that is matrixed with the rear channels (Ls & Rs) and decoded in a manner similar to Pro-Logic. Nonetheless a flag is included in such a 6.1 DTS or DD stream that will tell the decoder to activate and output something on the rear center channel, which will make this stream distinct in identification from a 5.1. DVDShrink might have checked and used this flag to identify a stream as duly 6.1. So, either DVDShrink can't make the distinction between a 5.1 and 6.1 or the stream is really 6.1 but flagged as 5.1 or the stream is really just 5.1. About two years ago when talk of Dolby Digital 6.1 was just coming up I rigged an extra old Dolby Pro-Logic receiver to retrieve a center channel from the Ls & Rs line-level outputs of a DVD set-top. After auditioning and comparing what to expect, in 5.1-only streams most rear channel info collapsed mainly into the rear center channel. With true 6.1 streams however rear channel info was spread more or less evenly across the three speakers and did not just collapse to the center. The collapsing-to-the-center effect is one of the things Dolby Pro-Logic II is supposed to minimize and I imagine even with a 5.1 stream it will make things sound better but as I have no extra DPL-II receiver I will not know for now.