CODEWITHSUNDEEP
midi
Rinaldi
Rinaldi

Reputation: 84

Midi Message need help

How do I interpret dwParam1 from the midiInProc delegate into midi status message like note-off, or note-on, control change?

Because as long i try dwParam1 is 254, and is not equal to note-off or anything else.

Upvotes: 0

Views: 667

Answers (4)

Nik Reiman
Nik Reiman

Reputation: 40430

The answer by @Conrad Albrecht is mostly right, but I wanted to chip in with an answer (instead of a comment), as I think that the original poster is probably being confused by MIDI running status.

If you are seeing bytes which don't resemble normal MIDI status bytes, you can assume that they are of the same type as the previous byte which you received. Therefore it is not only legal, but very common, to use MIDI note on events with velocity of 0 as a substitute for MIDI note offs.

You should just interpret these bytes as the normal second two bytes of a MIDI note on event.

Upvotes: 0

sean e
sean e

Reputation: 11925

Given that your question mentions dwParam1 and midiInProc, I'm assuming this is for Windows. When you receive MIM_DATA in your midiInProc, you can parse dwParam1 as follows:

For the status byte (command and channel), use LOBYTE(dwParam1).

For the first data byte, use HIBYTE(dwParam1).

If applicable, for the second data byte, use LOBYTE(HIWORD(dwParam1)).

Upvotes: 1

Brad
Brad

Reputation: 163538

I'm not entirely sure what you are asking, but I think you are trying to figure out how to interpret MIDI data.

I suggest this resource: http://www.midi.org/techspecs/midimessages.php

MIDI messages related to notes are differentiated by the first 4 bits, not by the whole byte. The last four bits of the first byte specify the channel.

Upvotes: 0

Conrad Albrecht
Conrad Albrecht

Reputation: 2066

You won't necessarily receive note-offs from every input device. IIRC it is legal for a device to send a note-on with volume=0 as a substitute for note-off. Also a drum stream (from a drum machine and/or on MIDI channel 10) I believe commonly contains only note-ons, no note-offs.

Upvotes: 1

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