DGPulldown and keeping chapter points?

[Matthew]

Lets say one is encoding at 25fps using a list of i-frames, then uses DGPulldown to get 29.97 fps.

How does one convert the frame values exactly, in order to get the chapter points?

The method I've currently used is to use FLOOR(29.97/25) and then let MuxMan pick the next i-frame (which will sometimes be the frame provided and sometimes be the frame provided+1).

To illustrate my point, example from below:
79656.6636 gets rounded down.
121813.6644 gets rounded up.

PAL PAL*29.97/25 Actual (from muxman)
0 0 0
11283 13526.0604 13526
18702 22419.9576 22420
21315 25552.422 25552
28203 33809.7564 33810
31815 38139.822 38140
34842 41768.5896 41768
38427 46066.2876 46066
43242 51838.5096 51838
49368 59182.3584 59182
54603 65458.0764 65458
66447 79656.6636 79656
81279 97437.2652 97437
86997 104292.0036 104292
101613 121813.6644 121814
109051 130730.3388 130730
117883 141318.1404 141318
126733 151927.5204 151927
131122 157189.0536 157189
140059 167902.7292 167903
147865 177260.562 177260
158527 190042.1676 190042
176257 211296.8916 211296
188158 225563.8104 225563
192763 231084.2844 231084
200035 239801.958 239801

[JetlagMk2]

The method I've currently used is to use FLOOR(29.97/25) and then let MuxMan pick the next i-frame (which will sometimes be the frame provided and sometimes be the frame provided+1).
That's all I do. It works for me so I never investigated it any further.

[Matthew]

Thanks for the reply.

I thought there may be some simple formula which would be applied, guess I'll just have to stick with the current method.

At a practical level the only problem I can think of is that if there are 2 i-frames in a row, the round down could result in the chapter point being one frame too early.

[Mr_Odwin]

Today I noticed a potential problem with the free version of Muxman that may also affect you. I was passing chapter points to it and they weren't quite lining up with what I thought it should be. It seems that Muxman assumes a framerate of 25 for PAL and 30 (not 29.97) for NTSC. I checked this by saving the project and looking at the mxp file.
So, in an NTSC project, setting frames 1800, 3600, 5400, 7200 meant that Muxman set chapter times of 1:00, 2:00, 3:00, 4:00, and using 1798, 3596, 5395, etc, lead to undesirable results.