Re-use barcodes already on CDs ?

[azrdev]

Searching for a nice way to physically select music to be played, I built a TonUINO based on NFC tags that I put into the jewelcases. This works (and using a pi would probably easily work without having to put the music onto a built-in SD-card first but using NFS/SMB), but requires an extra token for each album.
Since every?/most CDs already feature a Barcode on their backsides, I think it would be ideal to scan these and use the contained UPC/EAN code to lookup and play the album. I'd even try to get rid of the mapping code→path in the config file, utilizing barcodes in (ID3)tags (Musicbrainz already has those, it's just a matter of importing them into your local metadata).

Do you have any more thoughts / suggestions?

[bsaund]

@azrdev Cool Project! I plan to use something like NFC tags on arbitrary objection in addition to my binder of barcodes, one day.

Using the existing CD barcode is elegant, and a good suggestion. There still needs to be some mapping from [barcode -> URIs]. Currently I generate arbitrary barcodes and save an arbitrary mapping.

Using musicbrainz (or similar) we could get a mapping from [CD_barcode -> album_ID]. A possible architecture would be:

1. During creation, store a map from album_ID -> {path or URIs} for each album (some details would still need to be worked out. e.g. if you remove/add songs to the album folder, is it still the same album?
2. On scanning a barcode, if barcode maps to URIs, play
3. (optional 1) If barcode mapping fails, using musicbrainz map from barcode -> album_ID. Search locally for album with the same name (or other search criteria)
4. (optional 2) Using musicbrainz map from barcode -> album_ID. Lookup and play album from spotify

(3) means you can rip a CD to your local music folder, then scan the CD barcode. No further updates needed.
(4) enables a neat party trick, your friend comes over with a new CD, you can just scan the barcode and it plays. (Who brings CDs anymore though)

Note that I will never purely rely on CD barcodes, as I want to group collections of songs that were never on the same CD, or include some songs that were never on a CD in the first place.

Let me know if you have other thoughts

[azrdev]

I'd like to avoid the need to "setup" a new CD with the "scan barcode to play" component (i.e. musicbox). Ideally, replace 1-3 with a beets query for the read barcode (again, requiring it fetching that tag from mb: beetbox/beets#3172 ). E.g. configure something like mpc add in beets as music player, then just call beets play barcode:123456.

I like the idea of 4 very much, although it should be possible to completely disable that feature for privacy reasons.

Note that I will never purely rely on CD barcodes, as I want to group collections of songs that were never on the same CD, or include some songs that were never on a CD in the first place.

Now it's getting tricky. The only sane way I see to get there is to open a separate namespace of user-defined IDs. Maybe as simple as choosing a barcode format not yet used on CDs like QR (I hope so, at least), or prefixing user-defined IDs with some (magic) string.