Dolby Digital Plus and DTS-HD High Resolution Audio?

[BIslander]

Originally Posted by rded

As other memebers have said, DD+ was an HD DVD thing but is essentailly the same as the DD on Blurays killobits-wise just different labelling that's all as both are @ 640kps. Queen live @ montreal has DTS HR. It sounds really good..

Originally Posted by DRC72

I see... So in actuality when I switch from Dolby True HD to a Dolby Digital soundtrack on a BD, that can be considered Dolby Digital Plus?

Originally Posted by rded

Well, yes. For example, the DD+ on the HDDVD and the DD on the BD version of Batman Begins are bit for bit Identical but just labeled differently: i.e. one of them has a + and the other one doesn't. But don't confuse that with the regular Dolby Digital found on the DVD version as both the HDDVD and BD versions still have a higher resolution.

DD+ is not the same as DD 5.1 at 640kbps.

DD+ is a specific lossy format that supports eight channels with a 3mbps maximum bitrate on HD DVD and a 1.7mbps rate on BD. S/PDIF connections cannot be used for DD+. HDMI is required. DD 5.1 decoders cannot process DD+ bitstreams.

DD 5.1 has a maximum bitrate of 640kbps. However, the DVD spec limits it to 448kbps. HD DVD adopted the same 448kbps limit for legacy DD 5.1. DD+ was a mandatory format on HD DVD and it was the default track on most discs. When played back over S/PDIF connections, DD+ is transcoded to 640kbps DD 5.1. The same thing happens with TrueHD. (Actually, the first and second generation HD DVD players transcoded the Dolby formats to DTS.) So, sometimes it may appear that DD+ is DD 5.1 at 640kbps. But, that is not the case.

I have also read that the DD+ track on Batman Begins is encoded at 640kbps. That may be the case for that disc (and some others, most likely). But, it doesn't mean DD+ is merely a renamed 640kbps DD 5.1 encode. It is definitely a different format.