[LAD] Details about Mackie Control or Mackie Human User Interface

Takashi Sakamoto o-takashi at sakamocchi.jp
Tue Jul 21 13:53:44 UTC 2015

Hi Paul and Len,

Thanks for your replies.

On Jul 20 2015 22:41, Paul Davis wrote:
> On Mon, Jul 20, 2015 at 9:33 AM, Takashi Sakamoto
> <o-takashi at sakamocchi.jp> wrote:
>> Well, are there some developers who have enough knowledgement about MIDI
>> messaging rule for Mackie Control or Mackie Human User Interface(HUI)?
> not sure what you mean by "rule". I'm intimately familiar with both MCP and HUI.


>> As long as I know, for these models, there're three types of the
>> converter; usual MIDI messages such as Control Change (CC), Mackie
>> Control and Mackie Human User Interface, while I have a little
>> knowledgement about the latter two types.
> MCP and HUI both consist of "usual MIDI messages".
> There are a couple of sysex messages used for hand-shaking +
> discovery; everything else is just normal CC and note messages.

I also know the MCP and HUI is a combination of MIDI messages. What I
concern about is the sequence. If the seeuqnce requires device drivers
to keep state (i.e. current message has different meaning according to
previous messages), I should have much work for it.
In this meaning, I use the 'rule'.

Well, when DAWs and devices successfully establish the 'hand-shaking',
they must maintain the state, such as TCP? And in the 'discovery',
devices must retrieve informations from DAWs? Furthermore, in the
'rule', transactions (a set of requests/responses) are used?

On Jul 21 2015 01:25, Len Ovens wrote:
> It is (as Paul has said) straight MIDI. The best guide I know of is the
> "Logic Control User's Manual" from 2002. The MIDI implementation starts
> on page 105. The only thing maybe a bit odd is that there are encoders
> that use CC increment and decrement instead of straight values, but any
> sw written for these surfaces is aware of it.

It's noce, thanks. But the metering is one of my headaches...

On Jul 21 2015 01:25, Len Ovens wrote:
> You will note the use of pitchbend for levels. CC has only 127 values
> which can give "zipper" artifacts. If using CC, the values need to be
> mapped to DB per tick and/or have SW smoothing. The top 50db of the
> range are most important.

I think you mean that rough approximation fomula in acoustics
engineering for human perception (i.e. ISO 226:2003).

On 2015年07月21日 01:25, Len Ovens wrote:
> You get to make up your own midi map is what it finally comes down to.
> OSC might be a better option as the values can be floats and there is no
> limit to number of controls (Midi has only 127 CCs and some of those are
> reserved).

Currently, ALSA middleware has no framework for Open Sound Control. It
just has implementations for MIDI like messages. In this time, I use
rawmidi interface for my purpose. The MIDI messages will be available
for userspace applications to read from ALSA sequencer functionality.


Takashi Sakamoto

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