[LAD] ALSA Sequencer timestamp on event without scheduling

Clemens Ladisch clemens at ladisch.de
Fri Sep 30 18:46:49 UTC 2016

Felipe Ferreri Tonello wrote:
> This event we are discussing is time based.
> The only difference is that the event time is not its delivered time,
> but some time in the past.
> I just want to make ALSA Sequencer support this idea, which is new and a
> requirement for MIDI over BLE to work properly.

I see no such requirement in the BLE-MIDI specification, which says:
| To maintain precise inter-event timing, this protocol uses 13-bit
| millisecond-resolution timestamps to express the render time and event
| spacing of MIDI messages.
| Correlation between the receiver’s clock and the received timestamps
| must be performed to ensure accurate rendering of MIDI messages, and
| is not addressed in this document.

In the context of the ALSA sequencer, "rendering" means delivery.


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