Re: [Jack-Devel] Proposal: JACK MIDI API extension for system exclusive messages

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DateFri, 01 Apr 2011 17:12:14 -0700
From Devin Anderson <[hidden] at charityfinders dot com>
To"Tim E. Real" <[hidden] at rogers dot com>
Cc[hidden] at lists dot jackaudio dot org
In-Reply-ToTim E. Real Re: [Jack-Devel] Proposal: JACK MIDI API extension for system exclusive messages
On Fri, Apr 1, 2011 at 4:37 PM, Tim E. Real <[hidden]> wrote:
> On April 1, 2011 03:38:58 pm Devin Anderson wrote:
>> I think continuing to guarantee one complete MIDI event per
>> 'jack_midi_event_t' object is the best way to go.
>
> This means the event is not delivered to us until it is completely
>  received, possibly after several process cycles, right?

Correct.

> I know that the ALSA API breaks long received sysex into chunks and
>  delivers them.
> And I get an size error if sending one long sysex with ALSA, I need to
>  change our code to chunk them.

It's up to the MIDI driver to handle data chunks with whatever API
it's using.  JACK clients shouldn't need to care about blocking, MIDI
baud rate, etc.

> IIRC my (older) music keyboard sends chunked sysex.

Byte data always arrives in chunks of some sort, whether a chunk
represents a complete message, several messages, or one part of a
longer message.  It's up to the MIDI driver to make sure the data is
parsed into complete, valid MIDI messages, and delivers the data to
other clients just like any other JACK client.

-- 
Devin Anderson
devin (at) charityfinders (dot) com

CharityFinders - http://www.charityfinders.com/
synthclone - http://synthclone.googlecode.com/
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