# The MIDI Forum

## Resolved Calculate absolute time from PPQ and ticks?

0
Undo
1. Jonas
2. MIDI Software
3. Thursday, 28 November 2019
I decided to use PPQ afterall to be able to change tempo and maybe later export as midi here is an imported JSON event.
{
"duration": 1.2000000000000028,
"durationTicks": 1920,
"midi": 53,
"name": "F3",
"ticks": 34560,
"time": 21.599999999999998,
"velocity": 0.6614173228346457
},
But it was a long time since i programmed it, i basicly forgotten how.
Lets say our ppq "parts per quarter" is 960.

So 4 * 960 is one bar 3850?

Lets say i have BPM is 100 for the note that is "2400 ms timelapse" in one bar?
But i am not sure i understand the millisecond calculation, although i can see how it is done.
60/100=0,6 seconds/beat to get it milliseconds * 1000 gives us 600 but why would that be a quarter note?
600*4=2400 someone that understand notes maybe can explain?

So to calculate number of bars 34560/3850 = 8,976623376623377 bars?

To get the time we take a bar 2400 * 8,976623376623377=21 543,8961038961‬ ms

Is it that simple is there just a rounding error above in the JSON, or is it maybe the realtime recording?
Well i think it is correct but maybe someone else interested in doing some javascript, it is much easier when writing things down.

Jonas T
Comment
0
Undo
One beat is a quarter note, and a pulse is a tick, so with 100 BPM and 960 PPQ, you have 100 × 960 = 96000 ticks per minute. This is 96000 / 60 = 1600 ticks per second.
So the time, in seconds, is 34560 / 1600 = 21.6 s; the duration is 1920 / 1600 = 1.2 s.

A "quarter note" is just used as a unit of time, and not necessarily related to actual notes or bars in the song.

(MIDI files actually do not use BPM but a tempo value measured in microseconds per quarter note, i.e., BPM = 1000000 × 60 / tempo, or tempo = 1000000 × 60 / BPM.)

Please note that the tempo/BPM can change at any time, so you should compute all times relative to the last event. (See How to correctly convert MIDI ticks to milliseconds? for details.)
Comment
1. more than a month ago
2. MIDI Software
Responses (3)
0
Undo
???

if you have 100 beat / minute, each beat is 0.6 seconds or 600 ms.

Npw PPQ means part per quarter. there is 4 quarters in one full note right?

That means
960*4=3840
ticks in a full bar 4/4 right?
Isn't ticks = PPQ meaning "parts/partitions/ticks" per quarter note, not "parts/ticks" per minute????

?????100 BPM and 960 PPQ, you have 100 × 960 = 96000 ticks per minute?????????????

60/2.4=25 bars per minute.
And each bar is 3840 ticks so 25*3840=96000
So what you say is correct, but i do not get how, are you saying you can always multiply PPQ and BPM to get ticks per minute?

That a PPQ is partitioning number of the beat, i can see its turn out correct but i don't understand why?
OK i am a bit daft now i see a PPQ is simply a quarter note of 0.6 seconds in example and we have 100 of quarter notes with 960 ticks in a minute.

Case solved.

PS Why isn't it called QPM instead of BPM if a beat always correspond to a quarter note?
Well i guess BPM is an old term, but then why not call PPQ for PPB less confusion?
Comment
1. more than a month ago
2. MIDI Software
3. # 1
0
Undo
The SMF specification itself is internally consistent because it uses "quarter note" for both values, PPQ and tempo (= μs per quarter).

"BPM" is just a historically-grown term that happens to be easier to handle for humans, but who cares about those? ;-)
Comment
1. more than a month ago
2. MIDI Software
3. # 2
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