[Feature Request] traktor4 metadata about stemgen

[axeldelafosse]

Hey @kartguru,

That's a good request! I already tried to share the TRAKTOR4 tag between regular and stem files without any luck. I'm not sure I understand why Traktor isn't happy but it seems to ignore the tag and re-create it, as if it was corrupted. You can run your own experiments with a tag editor like mp3tag if you want.

Keeping this request open. I'd love to chat with someone from the Native Instruments team to learn more about this.

[stathius]

@axeldelafosse I have tried this and it works fine, the collection.nml metadata seem to have precedent over the tags in the file.

[stathius]

@kartguru Thanks for the link, I was under the impression that the TRAKTOR4 internal format was proprietary and undisclosed.
@axeldelafosse What type was your source file for the TRAKTOR4 tag? I was trying to compare how traktor stores TRAKTOR4 in mp3 vs m4a.

[axeldelafosse]

Hey @stathius! It is proprietary but it has been reverse engineered. We can decode it but we can't encode it.

I don't remember exactly, I think I tried on multiple formats (most likely lossless: WAVE, AIFF and FLAC) and then on stem files (ALAC stored in stem.m4a like this script generates). Please share your findings here!

[axeldelafosse]

A good workaround for this would be to let Traktor write the TRAKTOR4 tag by using the collection.nml file:

• Copy the metadata you want (key, tempo, hot cues) from the entry of the original file
• Paste it to the entry of the stem file
• (?) Force Traktor to use the new tags from collection.nml instead of the file tags by modifying the date of the entry to a future date in collection.nml
• (?) Force Traktor to write the new TRAKTOR4 tag

Should be pretty easy to do with https://github.com/wolkenarchitekt/traktor-nml-utils but I haven't tested it and I'm not confident about the behavior of Traktor re: writing and/or updating the tag.

[axeldelafosse]

Sweet! I'm closing this issue then. We can follow up on another issue or pull request if someone want to share this script here :)