Moving Chapters

[VRYK]

A video comprises 2 VTSs, the Root Menus for each being dummies. Since VTST 2 is a continuation of VTST 1, I wish to move its chapters to add them to VTST 1's chapters (which are 3 in number).

I would be grateful for guidance on which Pgc Editor command should be used.

[blutach]

You'll need to re-encode. Are the domain atrributes (especially the video) the same for both VTSs? If so, demux both VTSs and remux with muxman. Note you'll need to make a celltimes.txt file for your chapters which is a combination of the celltimes in VTS 1 and 2, where the celltimes in 2 are added to the last celltime in 1. This can be done in PgcEdit by using an offset for 2.txt and then cutting and pasting the offsetted celltimes into 1.txt

Regards

[VRYK]

Many thanks for your reply.

I see that the process is more complicated than I had suspected. I take it that the domain attributes are those shown under Domain Stream Attributes when right-click on the VTS in PgcEdit. If so, they are indeed the same.

Since I am new to Muxman, I wonder if you could you recommend a suitable introductory tutorial.

Incidentally, I once earlier asked where I can find a definition of “seamless” and you suggested searching in the PgcEdit Help file – I did so, but while the search threw up plenty of references to “seamless” I was unable to find a definition of the term.

Best wishes

[blutach]

There's no tute. It's just demux VTS 1 (you'll have an m2v and some ac3s) and do the same for VTS 2. Use PgcDemux for this.

Note the audio delay - they should be 0 for both.

In terms of celltimes, find out how many frames VTS 1 goes for. If its 75 minutes 47 seconds and 12 frames then its [(75 x 60) + 47] x 30 (NTSC) + 12. This will be your offset for VTS 2's chapters. If you are in PAL land, multiply by 25 instead.

Generate a celltimes.txt from VTS 1 (using PgcEdit). Check "output only chapters". Save it somewhere. Now, generate a celltimes.txt for VTS 2 with an offset of whatever. Cut and paste the numbers in this celltimes.txt into the one you saved. Resave.

In muxman, add the 2 m2vs and ac3s for each VTS (and any subtitles, if you have them). Then File → Import Chapter and browse to your celltimes.txt (the number of "scenes" will show how many combined chapters there are). Pick a place to stash your output and hit Start.

Re seamless: Go to the glossary and click the link in the first line (a more complete link ....). Select "S"

Regards

[VRYK]

Many thanks for you reply.

< It's just demux VTS 1>
I am a complete neophyte with Muxman, and haven’t found how to demux. Could you please hold my hand to help me get to first base.

Re Seamless – the link leads to “seamless playback”. I have a vague notion that when a video moves between 2 seamless cells no transition effect is apparent. But essentially I would like to know what are the attribute(s) that distinguish a seamless from a non-seamless cell ? – Since we are dealing here with uncompressed video, I take it there is no relationship to I and B frames.

Best wishes

[blutach]

Demux using PGCDemux. It will split your movie into an m2v (video), ac3 (audio) and sup (subtitle) tracks.

As for seamless, the attributes have more to do with the muxing. If it is muxed seamlessly, then it will play that way. There are flags in the IFO which tell if a cell is seamless. There are also rules which make certain cells non-seamless in certain conditions. But, essentially, the muxer will produce a seamless PGC for you.


Regards

[VRYK]

Many thanks for your reply.

The newly-created DVD is completely out of sync (Video-Audio); while the video in the first part (corresponding to VTS_1) is OK, the second part is plagued by severe pixellling, colour “flashing” etc. There appears to be an Audio Delay problem; instead of 0 for both demuxed VTSs, the respective LogFile.txt files show 26204 for VTS_1 and 14108 for VTS_2.

Cell Times (only chapters) show in PgcEdit’s PGC Editor for VTS_1 as 12 and 164439, with End Time (next offset) = 164451. Applying your formula (for PAL) to a running time of 1:49:38, gives 164450 which implies 1 frame extra.
Incidentally, what do these two numbers (12 and 164439) refer to respectively?

There seems to be a problem with the Cell Times for VTS_2 which has a running time of 1:14:47. Entering the 164451 offset, the Cell Times show as: 164463 and 164475
which seems to me to imply negligible values for VTS_2 as such.

Best wishes

[r0lZ]

The celltimes.txt file contains the frame numbers of the chapter changes. That's the format needed by Muxman, but you can also generate them in several other formats, easier to understand for human being like us!

The cell times may not be accurate if there is a still picture or ARccOS protected cells at the beginning of the PGC. Similarly, the last cell of the PGC might be a single black frame associated to a dummy chapter, to be able to jump to the end of the title with the Next Chapter button. You can verify that easily with the PgcEdit preview, and if they are really useless, you can try to get rid of them with PgcEdit, and then remove them from the VOB files with FixVTS. Then, demux and remux again. The audio delay should not be greater than 100 ms (or -100 ms.) With some luck, that method should be sufficient to resynchronize the audio with the video.

Have also a look at DelayCut. It might help if the audio delay is too big to be entered in Muxman's GUI.

The video problems in the second part are probably not related to the tiny cells. Are you sure the original DVD has been properly decrypted and ripped?

[VRYK]

Many thanks for your reply.

< The cell times may not be accurate if there is a still picture or ARccOS-protected cells at the beginning of the PGC>
I don’t believe there are any protected cells in the video. However, is there any check in PgcEdit for this ?

The Cell Sector Data for the original video are as follows:
Playback time End Time
VTST_1
Cell 1 00.00.00.12 00. .00.00.12
Cell 2 01.49.37.02 01.49.37.14
Cell 3 00.00.00.12 01.49.38.01
Celltimes 12, 164439

VTST_2
Cell 1 00.00.00.12 00.00.00.12
Cell 2 00.00.00.12 00.00.00.24
Cell 3 01.14.46.24 01.14.47.23
Celltimes 164463, 164475

That is, there are still pictures (in fact, blank cells) at the beginning of both VTSTs as well as at the end of VTST_1 and in Cell 2 of VTST_2. How can I check if Cell 3 of VTST_1 is used for the Next Chapter button ? (useful to know, even though in the present context where the objective is to merge the 2 VTSTs, it seems irrelevant).

Selecting the “Remove unref. and blank cells” option in FixVTS seems to be the default and I suppose should be kept.

< Are you sure the original DVD has been properly decrypted and ripped?>
Again, I would be grateful to know how this can be done. – by putting through FixVTS, e.g. ?

Best wishes

[r0lZ]

They might not be "protected cells", but anyway the presence of the tiny cells may be responsible of the problems. Try to remove VTST 1, cells 1 and 3, and VTST 2, cells 1 and 2. Then use FixVTS to strip them, with the Remove unref. and blank cells option on; that's correct.

You can use the Next Chapter button if cell 3 has a program (and normally also a chapter) number associated with it.

Normally, a good ripper should always rip the DVDs correctly, or it should display some error messages or warnings. Unfortunately, there are some bad rippers that simply silently fill the sectors they cannot read with garbage. Use DVD Decrypter to be sure.

[VRYK]

Many thanks for your reply.

I removed the cells (PgcEditor, <Remove Cells>) you suggested (VTST1, cells 1 and 3, and VTST 2, cells 1 and 2). I didn’t tick the ”Shorten the chapter table if needed”. Clicking <Remove Cells> brought up the warning: “Several programs are now pointing to the same cell. This situation might be illegal. You can fix it by clicking on the program buttons, but the programs will not be in sync with the cells any more”. Given the last phrase of this warning, I didn’t click on the Program buttons.

In response to “You must edit the chapter table to remove or re-assign chapters pointing to removed programs”, I removed VTST_1 cell 3 OK by clicking on <Edit Chapter (PTT) table> and then <Delete last chapter>, but how do I delete Cell 1 (I don’t find any “Delete selected Cell” button) ?

< Unfortunately, there are some bad rippers that simply silently fill the sectors they cannot read with garbage. Use DVD Decrypter to be sure.>
How can I check ex post that the rip was clean ? Would PgcEdit’s “Remove Useless Stuff” function do the job ?

Best wishes

[r0lZ]

To delete a cell, click the "Remove Cells" button in the PGC Editor, then select the cell number. (Take care: the cell number might not be equal to the program or the chapter number!)

The options to keep the programs and chapters unmodified are important only if you have a chapter menu and you don't want to modify it manually. Since you are re-authoring your DVD, it doesn't matter much if the programs and chapters are not correct, but it is probably better to untick the "Keep the programs in sync with the cells" option (in the Remove Cells window), and to shorten the chapter table. At the end of the operation, you should have only 1 program and 1 chapter per VTST.

Checking if a program has been correctly ripped is almost impossible, as the errors can be almost everywhere. Anyway, I don't think your problems come from a bad rip. Sorry, but I can't explain how to rip "difficult" DVDs, as it's against the rules of this forum.

[VRYK]

Many thanks for your help. I seem finally to have a reasonable end video thanks to your own and blutac’s advice. A couple of uncertainties on the way:
1. After deleting 2 of the 3 cells in each of the VTSTs, leaving only 1 cell in each, the celltimes were 0. Hence, I didn’t bother with File-Import Chapter in Muxman. Is this OK?
2. The Audio Delay was -472 in both VTSTs. As a problem, does this manifest itself by a lack of Video/Audio sync ? I didn’t apply DelayCut - should I have done so ?. In Muxman I left the Delay setting in the Audio section at 0 (the maximum setting is -300; should I have set it at this?).
Incidentally, on the question of deleting cells, |I have a VTST consisting of 7 PGCs each with 3 cells of which 2 are blanks, should I delete these blanks or just let sleeping dogs lie (I shall not be de-muxing and re-muxing) ?

With best wishes.

[r0lZ]

1. Yep, it's OK, but you could have defined a chapter point at the start of part 2 if you wish. (Just generate a celltime.txt file from part 1, but be sure to tick the "include end time" option.)

2. 472 ms is a big delay! (I consider that 100 ms is already a problem.) Use DelayCut to fix the problem, or at least add the -300 delay in Muxman, but you will probably still notice a slight problem.

3. The tiny blank cells are not a problem per se, but if they contain no audio and you want to join several parts together, as you know now, they are the cause of a/v sync issues.

Also, note that the minimal duration of a cell is about 1/2 second. The tiny cells are often made of only a single black frame, but that frame is played for a long time. If such a frame is included at the beginning or in the middle of a movie, it can confuse some players. So, IMO, it is better to remove them anyway when you re-author a movie. Of course, tiny cells at the end of the last part can safely be kept.

[blutach]

The spec says the max audio delay is 300ms (one way or another). So long as segment 2 is muxed properly, then there should be no issue. Use delaycut as r0lZ says.

Regards