Large Patch Collection Prepares The Linux Audio Drivers For MIDI 2.0
Almost forty years after the MIDI digital music protocol was first launched, in 2020 the MIDI 2.0 protocol was introduced as a significant overhaul for this broadly used customary by musical units. A giant patch sequence despatched out as we speak prepares the Linux kernel sound drivers for MIDI 2.0.
MIDI 2.0 permits for greater decision, higher articulation, the Common MIDI Packet (UMP) for packaging up a number of MIDI messages for simpler transport, much less jitter, and varied different new options and enhancements. The MIDI 2.0 specs have been obtainable from the MIDI Affiliation at MIDI.org whereas this morning is the primary time seeing the Linux kernel drivers being prolonged for MIDI 2.0.
Linux sound subsystem maintainer Takashi Iwai of SUSE despatched out the set of 36 patches — and roughly six thousand strains of recent code — for getting ready the kernel for MIDI 2.0 primarily with the USB Audio and uncooked MIDI drivers.
Takashi Iwai defined in the patch series:
“This can be a (largish) patch set for including the help of MIDI 2.0 performance, primarily focused for USB units. MIDI 2.0 is a whole overhaul of the 40-years previous MIDI 1.0. Not like MIDI 1.0 byte stream, MIDI 2.0 makes use of packets in 32bit phrases for Common MIDI Packet (UMP) protocol. It helps each MIDI 1.0 instructions for compatibility and the prolonged MIDI 2.0 instructions for greater resolutions and extra capabilities.
For supporting the UMP, the patch set extends the prevailing ALSA rawmidi and sequencer interfaces, and provides the USB MIDI 2.0 help to the usual USB-audio driver.
The rawmidi for UMP has a unique system title (/dev/snd/umpC*D*) and it reads/writes UMP packet knowledge in 32bit CPU-native endianness. For the previous MIDI 1.0 functions, the legacy rawmidi interface is offered, too.
As default, USB-audio driver will take the alternate setting for MIDI 2.0 interface, and the compatibility with MIDI 1.0 is offered by way of the rawmidi widespread layer. Nonetheless, consumer might let the driving force falling again to the previous MIDI 1.0 interface by a module possibility, too.
A UMP-capable rawmidi system can create the corresponding ALSA sequencer consumer(s) to help the UMP Endpoint and UMP Group connections. As a nature of ALSA sequencer, arbitrary connections between purchasers/ports are allowed, and the ALSA sequencer core performs the automated conversions for the connections between a brand new UMP sequencer consumer and a legacy MIDI 1.0 sequencer consumer. It permits the prevailing utility to make use of MIDI 2.0 units with out modifications.
The MIDI-CI, which is one other main extension in MIDI 2.0, is not lined by this patch set. It might be carried out relatively in user-space.”
The MIDI 2.0 code for the Linux kernel is now below evaluation and if all goes properly may doubtlessly be mainlined for the v6.5 cycle this summer season.