Forums > MaxMSP

### Frame rates and possible bug?

Nov 03 2009 | 2:17 pm

Hi All,

I’m trying to build a MAX set up, and I’ve got a quick question that maybe someone can give me some insight on, and, I also think I’ve possibly found a bug.

Firstly, frame rates…

I’m trying to create a timer that runs a somewhat accurate Time Code clock next to a Quick Time movie. Since not all of the QT movies I’ll be using actually have a Time Code track, and since the *actual* frame rates of the movies will often differ frame the visual timecode display in the movie, I’m simply divvying up the space between seconds in a user definable way (i.e. if the displayed time code in the QT is at 24 fps, but the ACTUAL frame rate of the movie is 15 fps, then I’m simply using the [scale] object to scale 0-15 as 0-24. Not complicated – but…)

What would be the mathematical way to deal with dropframes? I know that 29.97 is a frequently used frame rate these days – is that a mathematical way of expressing 30d? How often does a frame get dropped to keep things in sync? if something is a 24d frame rate, how many frames per second are there? 23 and a bit?

If anyone knows, it would help me hugely…

Also I think I found a bug… try putting a [umenu] into a MAX setup and making one of the entries ‘29.97’. Every time I do it, Max immediately changes it to be 29.96999. (which is close of course, but, not 29.97). Anyone else experiencing this?

Cheers,
Joel

Nov 03 2009 | 11:41 pm

To answer your question about the float display you might need to have "29.97" as a symbol, i.e. with the "quotes" in your [umenu] and then use [fromsymbol] directly afterwards. It does seem that the float display correction option from the max preferences makes no difference here.

lh

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Forums > MaxMSP