state extension: always save binary as UMP stream such as SysEx8 or MDS

[atsushieno]

Binary data incompatibility between plugin formats is one annoyance that should be resolved. We should take one step towards compatibility.

We will use Standard MIDI 2.0 UMPs to load and save state binaries. The content can be SysEx8, Mixed Data Set, or can be even MIDI 1.0/2.0 channel voice messages (if all of the state contents are about parameter values then it would still make sense). By explicitly stating this, the content will be sharable across platforms, even if the other devices are not Android or without AAP.

It will help interoperability between desktop and mobile.

Other examples of such portability: YAMAHA DX7 Cart made use of SysEx, and therefore there are many preset banks that could be still loaded by various DX7 emulators.

[atsushieno]

Should we rather use SMF2CLIP?

• advantages: we can add properties extensively in somewhat common manner
• disadvantages: we don't really need timestamps everywhere

Maybe it brings more annoyance over improvements for now.

[atsushieno]

I noticed there is "Get and Set Device State" MIDI-CI Property specification document. It certainly targets audio plugin state binaries. It is not very persuasive specification to conform to though.