PPQPos prim

[Spogg]

Hello!

Can anyone here kindly give me some information about the PPQPos prim please?
What it does, what it outputs, anything really.

There’s stuff on the forum which I’ve looked at but I would love a concise and accurate description if possible…

Cheers

Spogg

[tulamide]

PPQ means pulses per quarter. Aside from the typical grid of 16th, 32nd etc notes, midi transmits in a resolution, for example 96 ppq or 960 ppq.

PPQ pos will take that into account and give you a float value ranging from 0 to just under 4 for the first 4 quarter notes, etc.

However, there's an issue: While the VST documentation defines the float value as "quarter note", many DAWs (FL Studio is one of those) interpret it as "beats". So you always need at least the other prims like tempo, signature and bar start position, but most likely sample rate and sample position (but FL Studio messes with this value as well, so really stupid) as well, to make sense of it.

There once was a discussion about this topic, where I was involved. It is from a few years ago, so I couldn't find it that fast. But if you take time I'm sure you'll find it. It contains a lot more information on the implications and a workaround.

[Spogg]

Thank you tulamide.

I did read that huge topic you mentioned, but I got rather confused I’m afraid.

viewtopic.php?f=3&t=2732&hilit=PPQPos#p14221

I asked because I just wanted info on the prim itself.

I expect you expected this, but it leads me to another question. Does the float value wrap around to zero at some point, or does the value keep incrementing for the whole song?

Cheers

Spogg

[tulamide]

I expect you expected this, but it leads me to another question. Does the float value wrap around to zero at some point, or does the value keep incrementing for the whole song?

I'm glad you found the correct link, as it contains a lot of valuable information, when you want to make use of PPQPos! The value keeps incrementing.

[Spogg]

Thank you. I think that's all I needed to know. For now!

Cheers

Spogg

[trogluddite]

For completeness: the fact that the PPQPos doesn't wrap-around may cause problems if you work on long songs, due to it being only a single 32-bit float value. As the song plays back, the integer part ("1/4 note count") gradually consumes more and more bits of the float value's mantissa ("significant digits"), so that the fractional part ("place within the 1/4 note") gradually loses precision. In most cases, this won't be much of a problem, but it could be if you were trying to calculate "sample-accurate" values from the PPQPos, due to reduced accuracy further into the song.

[k brown]

The more I learn, the more I realize I don't know. . . .

[wlangfor@uoguelph.ca]

I think it is more sensible to just do the math yourself. You can do that by using the sample position prim and with tempo you have what you need to figure out an eighth of a bar.

The issue is that ppq is really for the most part FL studio only.

A nice idea though. I was thinking the other day the track length can be attained with a float hold max triggering to save to a queue when the sample point goes back to 0.