views:

29

answers:

1

Hello!

Given a BPM (beats per minute) MIDI delta time (leftmost bit off) with speed of 192:

0x00C0

I want to convert it to a FPS/TPM (frames per second / ticks per minute) delta time (leftmost bit on), but it should be the same (or the most accurate) speed value if you know what I mean.

For more info about MIDI Delta Time please take a look at Midi File Format under Header Chunk -> Time Division.

I am looking for a formula that will convert between these two deltatime types.

+2  A: 
Owen S.
Right. Ticks per beat. btw, 'tick' size is like TimeSpan.TicksPerSecond etc.? I am new to MIDI stuff, just trying to get involved. thanks for you help, your response is indeed complex, it will help if you could simplify it, or else i will have to dig in it more...
Shimmy
@Shimmy: They're not the same tick, though the concept is similar. When TimeSpacn refers to ticks, it's referring to a unit that's defined by the OS, which tends to have a fixed relationship to seconds. Ticks in the MIDI world are an abstract unit defined by the time division, and may or may not have a fixed relationship to seconds or to OS ticks for that matter. The purpose of both ticks is to represent time efficiently by using integer values, yet to choose an interval of time between integers that's small enough to allow you to describe timings moderately precisely.
Owen S.