Skip to main content ↑ ↓

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: Can DSD layer of SACD include both 2.0 and 5.1 audio? (Read 5216 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Can DSD layer of SACD include both 2.0 and 5.1 audio?

(Perhaps entirely the wrong forum, but I couldn't see anywhere obvious for discussion of SACD)

In the Wikipedia article on SACD it says, "Commercial releases commonly included both surround sound (five full-range plus LFE multi-channel) and stereo (dual-channel) mixes on the SACD layer", attached to which is the ubiquitous Wikipedia "[citation needed]". I believe that this is not referring to "hybrid" discs that have a DSD layer and a PCM layer, but that the DSD layer on its own can include both a 2.0 mix and a 5.1 mix.

Is this true? I didn't know that. I'm just curious.

Can DSD layer of SACD include both 2.0 and 5.1 audio?

Reply #1 –
Quote from: osullic on
(Perhaps entirely the wrong forum, but I couldn't see anywhere obvious for discussion of SACD)

In the Wikipedia article on SACD it says, "Commercial releases commonly included both surround sound (five full-range plus LFE multi-channel) and stereo (dual-channel) mixes on the SACD layer", attached to which is the ubiquitous Wikipedia "[citation needed]". I believe that this is not referring to "hybrid" discs that have a DSD layer and a PCM layer, but that the DSD layer on its own can include both a 2.0 mix and a 5.1 mix.

Is this true? I didn't know that. I'm just curious.


I have some SACD ISOs, and when I load them in foobar2000, it shows all the tracks listed twice, with the second half being the 5.1 mixes.  The 5.1 mixes may just be additional tracks at the end of the disc, rather than a whole other layer.

Can DSD layer of SACD include both 2.0 and 5.1 audio?

Reply #2 –
Quote from: osullic on
(Perhaps entirely the wrong forum, but I couldn't see anywhere obvious for discussion of SACD)

In the Wikipedia article on SACD it says, "Commercial releases commonly included both surround sound (five full-range plus LFE multi-channel) and stereo (dual-channel) mixes on the SACD layer", attached to which is the ubiquitous Wikipedia "[citation needed]". I believe that this is not referring to "hybrid" discs that have a DSD layer and a PCM layer, but that the DSD layer on its own can include both a 2.0 mix and a 5.1 mix.

Is this true? I didn't know that. I'm just curious.


Dual layer DVDs are what they say - a DVD with 2 independent layers. Thy are composed of two different physical disks each half the thickness but full data capacity, bonded together. The layers can be used for dissimilar formats like CD and DVD or they can be used for 2 independent or dependent sets of DVD layers.

A standard DSD-1 stereo track requires about 2.8 GB per stereo audio track.  A standard DVD layer has capacity for 4 .7 GB of data. It would appear that it would take two layers to hold 5 full-range tracks, with some space left over for a reduced bandwidth 0.1 mono track.  However I've heard stories about 10 channel surround.

Multichannel SACDs have their  multi-channel tracks compressed using DST, a lossless compression format.  The compression factor is roughly 2.5:1. This allows storage of 5.1 channels in the space available on one layer.

One problem is that SACD is a proprietary format revealed to just a few licensees as compared to CD audio with many licensees over a period of decades, and accurate detailed technical data about it is difficult to find. It is a bitstream format that lacks an structure that  exactly  corresponds to a PCM sample.

Can DSD layer of SACD include both 2.0 and 5.1 audio?

Reply #3 –
There is some interesting info in this pdf from Sonic Studio, one of the SACD authoring workstations.
IMO it clearly illustrates the different layers of the SACD format.

Can DSD layer of SACD include both 2.0 and 5.1 audio?

Reply #4 –
Quote from: Kees de Visser on
There is some interesting info in this pdf from Sonic Studio, one of the SACD authoring workstations.
IMO it clearly illustrates the different layers of the SACD format.


Great reference (with some caveats)! Slides 6 and 7 may answer the OPs question. A SACD  may be composed of both 2 channel and Multichannel (Mch) datasets. It may have one or two layers. It appears that a given 2 channel or Multi channel  data set must be complete on one layer. Either may be losslessly compressed using DST.

Unfortunately it also appears to be a piece of anti-PCM propaganda, shamelessly misleading the reader to ignore the fact that DSD is both band limited and has dynamic range limitations.  This misdirection is clearly shown in slides 11, 12, and 27. I recommend stepping over the misleading info to benefit from such valuable true information as it contains.

Can DSD layer of SACD include both 2.0 and 5.1 audio?

Reply #6 –
Quote from: Kees de Visser on
There is some interesting info in this pdf from Sonic Studio, one of the SACD authoring workstations.
IMO it clearly illustrates the different layers of the SACD format.


Thanks for posting the link. That is indeed an interesting document. I think it answers my question. Slide 5 indicates that all SACD discs are in fact dual layer, and that "single layer" discs are implemented by one layer being a "dummy". Slide 6 indicates that the HD layer contains (or at least may contain?) a 2-Channel Stereo Area as well as a Multi-Channel Area.

So that means that a hybrid disc could contain high-res 2.0 audio and high-res 5.1 audio in addition to the 2.0 CD audio.

Can DSD layer of SACD include both 2.0 and 5.1 audio?

Reply #7 –
Quote from: osullic on
Quote from: Kees de Visser on
There is some interesting info in this pdf from Sonic Studio, one of the SACD authoring workstations.
IMO it clearly illustrates the different layers of the SACD format.


Thanks for posting the link. That is indeed an interesting document. I think it answers my question. Slide 5 indicates that all SACD discs are in fact dual layer, and that "single layer" discs are implemented by one layer being a "dummy".


Both unlikely and contradicted by other sources:

Wikipedia DVD Article

"A dual-layer disc differs from its usual DVD counterpart by employing a second physical layer within the disc itself."

The second layer is arguably more expensive than the first because the two need to be molded and assembled. A standard DVD is a single piece like a CD.

Quote
Slide 6 indicates that the HD layer contains (or at least may contain?) a 2-Channel Stereo Area as well as a Multi-Channel Area.

So that means that a hybrid disc could contain high-res 2.0 audio and high-res 5.1 audio in addition to the 2.0 CD audio.


Agreed. It could contain both 2 channel and 5.1 DSD datasets on the same layer.