Correct way to copy celltimes from PgcDeumx into CCE then muxman for NTSC film

[FlimsyFeet]

If I understand it correctly, when you extract celltimes.txt from PgcDemux for a 23.976fps NTSC film Pgc, you need to multiply by 0.8 to get the actual frame number.

What happens if you don't get a whole number, e.g. 8791 * 0.8 = 7032.8? If rounding to the nearest, you would expect it to be 7033, but if you use IfoUpdate to get the chapter points for CCE, it seems to truncate the decimal and give 7032.

CCE timecodes for chapters, to insert I frames in the correct places, seem to be based on 24fps. So 7032, adding on the 1hr offset, would be 01:04:53:00 annd 7033 would be 01:04:53:01. Is that right?

When you reload the celltimes.txt into Muxman, where would it look to put 8791? If it looks to put it at 7033, and my I frame is at 7032, would it then miss the start of the chapter?

I should mention that I'm intending to use Vobblanker to put the re-encoded, remuxed PGC back into the the original disc's structure, and want the chapter menus to be as near enough as possible frame accurate to the original.

Sorry for the long confusing post!

[bigotti5]

If I understand it correctly, when you extract celltimes.txt from PgcDemux for a 23.976fps NTSC film Pgc, you need to multiply by 0.8 to get the actual frame number.

NTSC DVD Video always has a framerate of 29,97 (even if there are 23,976 really encoded frames).
Pgcdemux does not alter the RFF (=pulldown) flags, so demuxed mpeg2 video has a framerate of 29,97 too.

[FlimsyFeet]

But I'm using DGIndex with Forced Film to load the M2V into AviSynth, then open the AVS file in CCE.

So CCE sees 23.976fps as the input. Which means I need to convert the chapter points into the equivalanent 24fps timecode to tell CCE to put I frames at the start of each chapter.

(The output from CCE is 29.97 fps, because altough it encodes at 23.976fps progressive it puts the pulldown flags into the stream for you to make it DVD compliant.)

[mpucoder]

Both frame numbers are "actual" frames, but because of pulldown there are encoded frames and displayed frames. the original DVD should have its chapter points on I frames, and ideally that I frame would be the start of a pulldown sequence (rff=0, tff=1). If the pulldown is following a regular cadence the displayed frame number (what PgcDemux gives you) should be a multiple of 5 and the encoded frame number a multiple of 4. However, this does not happen in real life.

I'm not familiar with how IfoUpdate determines the frame number, if it is counting only encoded frames then its value is correct for CCE.

One way to tell if it all lined up is to look at MuxMan's log. Every chapter will begin on the first I frame at or beyond the frame number you requested. For any chapters that miss lower the frame number by one and try again.
Starting scene Segment_1_scn1 at 00:00:00:00 (0 fields)
Starting scene Segment_1_scn2 at 00:00:59:28 (3597 fields)
Starting scene Segment_1_scn3 at 00:02:00:05 (7210 fields), requested for 00:01:59:26
Starting scene Segment_1_scn4 at 00:02:59:27 (10795 fields), requested for 00:02:59:24

in the above example the first 2 chapters lined up, the third and fourth missed. Also note that chapter 2 begins on an odd field number, indicating it is not at the start of a pulldown sequence. the actual request was for frame 1798.

[FlimsyFeet]

:thanks: for the clarification mpucoder, it's much appreciated.