Amending the Style / Release / Medium Format to better handle SACDs

Tags: #<Tag:0x00007fbb39bcce28> #<Tag:0x00007fbb39bccd60>

Hi,
I think this post is of interest to @reosarevok so hopefully he’ll chime in.

In lieu of a schema change to handle the different tables of contents (ToCs) on SACDs, I want to make changes to the style guide that relates to the Medium Format of Releases.

As I see it it the current version has two issues:

  1. it permits incomplete edits “for the sake of convenience”, which, given how trivial it is to add a second identical track list, seems unnecessarily generous, and
  2. it does not address the multiple ToCs possible on the SACD layer.

The current de facto? approach seems to be just to “tack on” any multi-channel ToC after any existing 2-channel ToC. However I’ve seen SACDs with 2CH and MCH DSD ToCs created with the SACD medium holding only the MCH ToC. Someone wanting to record the 2CH tracks would need to add these after the MCH tracks. In any case having track numbers exceed the offical track list count is wrong.

The flow-on effect from this is that when tagging the individual files from a complete Hybrid SACD rip you end up with:

  • one release
    • two media
      • medium one with 5 tracks (for example)
      • medium two with 10 tracks (half of them with 5.1 mix in the title)

Good luck playing the second medium on shuffle :slight_smile:

I’ve also seen SACDs with a single medium (Hybrid SACD) include both 2CH and MCH ToCs which is also wrong (it should be at least a Hybrid SACD (SACD Layer)).

Given any schema change is likely going to add 2CH and MCH medium types (to represent the SACD DSD ToCs) I propose that the style guide

  1. mandate the creation of releases with all ToCs, and
  2. mandate the 2CH and MCH ToCs be added to two separate media (both SACD Layer).

This honours the track numbers of each ToC, and will be easy to make compliant should a schema change add new media types. The two SACD layer ToCs are differentiated by the use of “x mix” in their track titles.

As a side note I wish the style guides used IETF RFC2119 language, such that phrases like “but any hybrid SACD that has been entered as two layers shouldn’t be changed” would read “but any hybrid SACD that has been entered as two layers MUST NOT be changed”.

Thanks

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I don’t understand your comment “Good luck playing the second medium on shuffle”. If your playback system is capable of both stereo and multichannel playback I don’t see what the problem would be.

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That’s the least of my arguments here admittedly, but the idea that when tagged you get (for a 5 track album) tracks 1 through 10 is not the playback experience you’d expect. Indeed: one of my stereo listening posts has a renderer which expects DSD to be sent as DoP. When the playing device sees a MCH FLAC, not knowing that it’s DoP, it tries to do the right thing and downmixes it to 2CH. Of course when I play that medium at that listening post half of the tracks play perfectly as DSD, the other half as static. If it were two media I could simply choose to play the 2CH one.

If I have a hybrid SACD but no SACD player, I might have no way to check what exactly is on the SACD part, so mandating that would be frustrating. Even worse when all I have is an online tracklist that doesn’t specify anything else at all (pretty common!).

I’d be ok with that if that’s something SACD people want (I guess if we already have more media than discs it isn’t too important how many media we have). In that case, I’d expect we’d want two new medium formats Hybrid SACD (SACD layer, multichannel) and Hybrid SACD (SACD layer, two channels), and possibly also two more for pure SACD? I have never used a SACD, so I’m not too up to date with them! :slight_smile:

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By TOC, do you mean Disc ID or tracklist?

Table of Contents - as I understand things it’s the SACD nomenclature for what MB would call a “track list”. An SACD cover might show a single track list but have up to three ToCs.

While I think it’s a rare case that a contributor gets the track metadata from the actual medium (without access to a case insert, images of cover art, etc.), I agree that it’s better to have no information (upon which someone else can add) rather than bad information. However the style guide specifically says that when information is available you can get by without adding it, to wit: “When a hybrid SACD has the same tracklist… just [add] a single medium”. This implies that the contributor knows the track listings.
Perhaps I’d request that the guide:

  • mandate the creation of releases with all known ToCs

That request has been created (https://tickets.metabrainz.org/browse/STYLE-1426 - you’re the assignee). The point of this conversation is not to duplicate the work on the schema but rather have the style guide changed in the interim. I have a lot of SACDs I want to add to MB and tag but am holding off as I can’t get the votes without the style guide changing. At this point I’d be content with (as mentioned above) having two SACD layer media with 2CH and MCH track lists.

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That’s a trivial change, I just need to know that people who use SACDs actually agree on this :slight_smile:

Well, +1 from me (obviously :slight_smile:). For both changes to the style guide and schema.

So what happens now?

As long as there is no possibility to have multiple areas/sections on a medium, I would also prefer three fake mediums over two fake mediums for Hybrid-SACDs with stereo and multi-channel audio.

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What about non-hybrids? (where it’s probably “one non-fake medium but more annoying vs two fake mediums”, if I understand correctly).

What do you mean by fake media? A ToC? A physical layer? MB is using a medium to mean a few different things.

As per a comment I just added to the ticket:

From a data perspective do we really care if an SACD is hybrid or not? Why not simply have three SACD medium types:

  • SACD CD layer <-- the Redbook layer
  • SACD DSD layer (2CH) <-- also covers mono, stereo, and dual stereo (should be mentioned in style guide)
  • SACD DSD layer (MCH) <-- covers >2 channels (2.1 ,4.0, 5.1, etc.)

Job done. People can mix and match depending on the release and the information at hand.

Perhaps use the disambiguation field to mention Hybrid if someone really wants it.

In most cases, a medium in MB (and IRL) is one physical item that you can hold in your hands. The exceptions are Digital Media (not relevant for this discussion) and the options for layers or sides of SACD, DualDisc etc. which I call “fake media” because they only represent a part of the physical medium. By using the current definitions I prefer three “fake/virtual media” (medium defined as a separate TOC) over two “fake/virtual media” (medium defined as a separate layer).

I would also prefer to use two “fake/virtual media” for standard SACDs with stereo and multichannel audio for the above reasons. A medium should be defined as a separate TOC (independent data section) for these special cases. They weren’t part of my original answer because my focus is on Hybrid SACDs.

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Fair enough. I prefer the phrase “virtual media” but that’s just me.

SACDs are tricky in this regard. Then can be:

  • A single medium holding DSD only and may contain one or two ToCs
  • Two bonded media (layers) holding Redbook PCM and DSD (with one or two ToCs)
  • Two bonded media (layers) holding DSD only that spans both media (with one or two ToCs)

Recording each combination is too onerous, which is why I just suggest recording the three types of ToCs and ignore the medium types. This accommodates the various SACDs out there and maintains the track numbering.

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Count me in. Fake always sounds a bit like there is an ill intent behind it.

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I think what you call a ToC, you should, from now on, call it either a Layer (from Medium types) or a Layer Tracklist (from Medium types and release editor tab).
I think that’s the MB terminology.
Things are already confusing enough to add more words for same concepts. :wink:

Or can there be more than one TOC on a Layer, really?

Of course: the DSD 2CH and MCH ToCs on an SACD reside either on one layer (for hybrid and single layer SACDs) or both layers (for a dual layer SACD).

Hence my terminology. :slight_smile:

I think we should use the term “Format”, or “Medium Format”, as that’s the MB field name.

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I doubt that there “a lot of SACDs” left to add… between Cheezmo and me we should have most of Jazz/Modern music covered. Classical releases require a lot more effort/time on the other hand, that’s why I don’t add as many.

So: if I made the change to have separate media for stereo and multichannel, would everyone be (at least moderately) happy, or does someone think that’s significantly worse than the current situation? :slight_smile:

The end is nigh! (s0rry :stuck_out_tongue:)