Add OneLibrary support

[brotherkaif]

(Note: This issue was originally posted to the Mixxx repo (issue 15556), but it was suggested that it would be more appropriate to raise it for the libdjinterop project instead)

Feature Description

OneLibrary is a new initiative from AlphaTheta that attempts to create a unified USB export format that is compatible with other DJ software.

Currently, this has been implemented by Traktor, DJay Pro and Rekordbox (with Serato support rumoured to be coming soon).

This presents a great opportunity for libdjinterop (and by extension, Mixxx) to increase compatibility with other parts of the DJ ecosystem. Having an open source DJ application support the standard will dramatically lower the barrier to entry for a lot of potential DJs around the world. Adopting the standard will also allow applications that use libdjinterop to seamlessly export CDJ compatible USB sticks with full cue point and beatgrid support. This will be a great addition to the libdjinterop feature set which already can export to Engine DJ compatible gear.

The ideal implementation would be similar to what DJay offers:

• The ability to export playlists, cues and beatgrids to a USB stick in OneLibrary format
• The ability to import playlists, cues and beatgrids to a USB stick in OneLibrary format
• The ability to create a new OneLibrary database on a cleanly formatted USB stick
• The ability to interact with an existing OneLibrary database on a USB stick that has been created on other DJ software

Unfortunately AlphaTheta has not made the specification public, nor does it appear to managed by a consortium. However, they do appear to be open to partnering with other software; There may be an opportunity to begin a dialogue with AlphaTheta. Alternatively, the specification may need to be reverse engineered.

[mr-smidge]

Hi @brotherkaif , thank you for raising this.

Do I understand correctly this is another name for Device Library Plus?

If so, an official spec would certainly help! Reaching out to AlphaTheta for regular dialogue may involve a time commitment that I'm not sure I have, but I will have a think.

I'd love it if this library could support more than just Engine!

[BrandonLogandi]

Do I understand correctly this is another name for Device Library Plus?

Indeed, AlphaTheta mention in their FAQ that OneLibrary is basically a rebrand of Device Library Plus and they're compatible with each other.

In fact, there's even a Python library that, among other functions, has the ability to interact with the DLP database: https://pyrekordbox.readthedocs.io/en/latest/formats/devicelib_plus.html

[mikelpr]

@BrandonLogandi nice and it seems it might already handle writing since it has many add_* methods

but, should we use it (being a python library and using python's sqlite) or rewrite in C++?

[mr-smidge]

but, should we use it (being a python library and using python's sqlite) or rewrite in C++?

Libraries that grow 'organically' don't always line up neatly. And so we have a library for Engine (libdjinterop) in C++, and a library for Rekordbox (pyrekordbox) in Python 😆.

My gut reaction is that if we want support for Device Library Plus in libdjinterop, then it should be in C++, using the "low-level API" design approach already used for Engine V2/V3.

The value-add of libdjinterop is meant to be not only low-level access to DJ database formats, but also a high-level normalised format that can handle all the common use cases in a format-neutral manner.

[mr-smidge]

My suggestion for how to do this ticket might be to break it up into smaller chunks:

• Create a skeleton low-level API for Device Library Plus.
• Add functionality to this incrementally.
• Once functionality is at a decent level, add a high-level API implementation.

I've written up an intro to the high-level vs. low-level API concept in some new documentation, which may prove useful for anyone who might want to help with this ticket!