How to get MIDI Type

[rualark]

Hi!

How can MIDI Type be detected (0, 1, 2)?
Like midifile.GetMIDIType()

I see that it is loaded in MidiFile::read, but seems that it is not stored as class member variable. Possible solution is to convert type variable to a member variable.

// Header parameter #1: format type
int type;
shortdata = readLittleEndian2Bytes(input);
switch (shortdata) {
	case 0:
		type = 0;
		break;
	case 1:
		type = 1;
		break;
	case 2:
		// Type-2 MIDI files should probably be allowed as well,
		// but I have never seen one in the wild to test with.
	default:
		est.Format("Error: cannot handle a type-%hu MIDI file.", shortdata);
		m_rwstatus = false; return m_rwstatus;
}

// Header parameter #2: track count
int tracks;
shortdata = readLittleEndian2Bytes(input);
if (type == 0 && shortdata != 1) {
	est.Format("Error: Type 0 MIDI file can only contain one track. Instead track count is: %hu", shortdata);
	m_rwstatus = false; return m_rwstatus;
} else {
	tracks = shortdata;
}

[craigsapp]

A good idea would be to add a function called MidiFile::getOriginalType(). Otherwise, the MIDI type is handled automatically by the MIDI class: if there is one track then it is type-0 and if there are two or more tracks it considered type-1 (and MIDI files are written according to the track count as well).

[zhangyufei49]

Hi!

How can MIDI Type be detected (0, 1, 2)?
Like midifile.GetMIDIType()

I see that it is loaded in MidiFile::read, but seems that it is not stored as class member variable. Possible solution is to convert type variable to a member variable.

// Header parameter #1: format type
int type;
shortdata = readLittleEndian2Bytes(input);
switch (shortdata) {
	case 0:
		type = 0;
		break;
	case 1:
		type = 1;
		break;
	case 2:
		// Type-2 MIDI files should probably be allowed as well,
		// but I have never seen one in the wild to test with.
	default:
		est.Format("Error: cannot handle a type-%hu MIDI file.", shortdata);
		m_rwstatus = false; return m_rwstatus;
}

// Header parameter #2: track count
int tracks;
shortdata = readLittleEndian2Bytes(input);
if (type == 0 && shortdata != 1) {
	est.Format("Error: Type 0 MIDI file can only contain one track. Instead track count is: %hu", shortdata);
	m_rwstatus = false; return m_rwstatus;
} else {
	tracks = shortdata;
}

• Type 0 means all event in a single track
• 1 means multi tracks shared tempo and time-sign meta events
• 2 means multi tracks don't shared tempo and time-sign info

Type 1 is most common used.
Imagine a piano music score has 2 voices with different tempo at the same time point.
Your left hand need to play 90BPM and right 120.
Human can't play it properly. That's why format 2 is so rare