SetTempoEvent data interpretation? about python-midi HOT 3 CLOSED

Resolution only expresses how many ticks there are per beat (it's called "resolution" because it determines how many samples the MIDI signal communicates for every beat). It does not have a bearing on the relation between time and meter.

Calculating from 60bpm:

60 bpm = 1 beat per second = 1000000 microseconds per beat

Tempo events are expressed in microseconds, so your event should have a value of 1 million. But the data array uses 8-bit words, so this number gets split up by powers of 256:

1000000 = (15 * 256^2) + (66 * 256) + (64) = [15, 66, 64]

But you don't actually have to worry about this form if you don't want. The SetTempoEvent class has helpers for using BPM & microseconds-per-quarter-note: get_bpm, set_bpm, get_mpqn, & set_mqpn.

from python-midi.

get_mpqn is handy. Why not make the data values hex, though, so that you can just concatenate and convert?

Also, thanks for the quick response.

from python-midi.

I can't speak for @vishnubob, but I think the point is that the data array should always try to parallel the MIDI's binary data (and Python handles hexadecimal as strings, so that would be a lot of conversion work). Getters and setters should be the primary method of interacting with the values.

Also, among the non-varlen events, nearly all of them have word-width data fields that are naturally interpreted as integers. The tempo event might be the only exception. So defaulting to 8-bit ints is pretty sensible in most cases.

from python-midi.