I cannot Find any Functions to delete MIDI Events

[FFjet]

I want to delete some events in a track!But I don't know how to do it lol.
Please Help! ;D

[john-davies]

I needed this as well so I've created pull request #52 which gives options for adding or deleting events from a list.

[craigsapp]

There was no way of deleting MIDI events(!), but finally I have done something about it...

The example program https://github.com/craigsapp/midifile/blob/f1d049169ddf974c9f5a230d1885e626dea979c3/src-programs/removenote.cpp demonstrates how to use the new deleting system. In the example program, here is the code which goes through the MidiEvents and applies array<uchar>::clear() to the MidiMessages that should be deleted:

midifile/src-programs/removenote.cpp

Lines 35 to 51 in f1d0491

	// Delete any MIDI message which is a note message on key 63:
	int removekey = 63;
	for (int i=0; i<midifile[0].getSize(); i++) {
	if (!midifile[0][i].isNote()) {
	continue;
	}
	if (midifile[0][i].getP1() == removekey) {
	midifile[0][i].clear();
	}
	}
	// calling MidiFile::removeEmpties() is optional, since
	// writing the MidiFile will automatically skip over any
	// MIDI events with no message content:
	midifile.removeEmpties();
	cout << midifile;

In the example program I write notes on MIDI keys 60, 61, 62, 63, 64, 65, and then delete the ones on key 63. The output from the program should have the 63 note messages removed:

"MThd"			; MIDI header chunk marker
4'6			; bytes to follow in header chunk
2'0			; file format: Type-0 (single track)
2'1			; number of tracks
2'120			; ticks per quarter note

;;; TRACK 0 ----------------------------------
"MTrk"			; MIDI track chunk marker
4'44			; bytes to follow in track chunk
v1	90 '60 '64	; note-on C4
v1	90 '60 '0	; note-off C4
v1	90 '61 '64	; note-on C#4
v1	90 '61 '0	; note-off C#4
v1	90 '62 '64	; note-on D4
v1	90 '62 '0	; note-off D4
v1	90 '64 '64	; note-on E4
v1	90 '64 '0	; note-off E4
v1	90 '65 '64	; note-on F4
v1	90 '65 '0	; note-off F4
v0	ff 2f v0	; end-of-track

When the MidiFile is written at line 51, any MidiEvents that have no byte content (according to vector<uchar>::empty() will be ignored. So the empty MidiEvents do not have to actually be deleted from the MidiEventList in order for them to be ignored.

As done on line 49, you can optionally remove the empty MidiMessages from the MidiFile/MidiEventList by calling MidiFile::removeEmpties() (or MidiEventList::removeEmpties() to remove empty message in a specific track).

This system is implemented in commit f1d0491