Unable to remove blank frames from a cell

[Bob_5000]

Hello, may I say what a great site and forum this is.
After my old dvd player, which wouldn't play recorded media, finally packed up, I finally got a new dvd/hdd recorder. This has now prompted me to backup all my dvd's. After spending the last 1 1/2 weeks searching this site and these forums, I am now able to comfortably rip the main movie remove credits, etc. from the VOB's before demuxing, demux the files re-encode using CCE and rebuild the dvd to dvd5 size with minimal quality loss. I am also able to convert to avi and perform basic editing, etc. Not bad seing as I didn't have the first clue 2 weeks ago and for that I am grateful to all who contribute to this site and forums.
In all this my primary concern is quality over speed and so want to perform everything manually to control every step.
I having followed this excellent guide http://forum.doom9.org/showthread.php?t=126932&highlight=merge to merge films split over 2 dvd' and am happy with this so far. Fortunately the films I have worked on so far have had the blank frames at the end of the 1st disc in a seperate cell and so I have removed the cell to remove the blank frames and ensure a seamless join, which has worked perfectly.
My problem now is with LOTR - FOTR EE PAL version. The first disc has a final cell with about 12 blank frames which I have removed, but the previous cell has action followed by another approx 12 blank frames. I have tried to removed the frames with vobBlanker. I understand that vobBlanker's fine control section only navigates I frames in the cell, but it will not navigate as far along the cell to the blank frames. I assume that the first blank frame must be an I frame but I cannot navigate to it in order to set it as a cut point. I can only navigate as far as the previous I frame which is about 12 frames before the blank frames start. I have made the cut here and if you didn't know any better you wouldn't know that the cut was in the wrong place, BUT I know it will bug me when I watch it and ideally I would like to cut only the blank frames out. Is there any way to do this or is what I have the best I can get. Or if I am right in assuming the first blank frame should be an I frame, then is there a slight bug in vobBlanker??

Sorry if this is a bit long winded and thanks in advance for taking time to help

[blutach]

Welcome to Doom9!

See if you can use the VOBU Plugin in PgcEdit to set the desired end frame of the cell. Then remove the now unreferenced material with VobBlanker, FixVTS, or even DVD Shrink.

Regards

[r0lZ]

You are right when you say that a cut point must be on a I-frame. However, there are commercial programs that can be used to cut at any frame. (The remaining frames in the GOP are re-encoded.) Have a look at VideoReDo or Womble MPEG Video Wizard DVD. Unfortunately, those apps are not able to process more than one audio stream, and doesn't support subtitles at all.

However, IMO, leaving some black frames between two chapters is not very annoying. Remember that the duration of a GOP is less than 1/2 second.

[Bob_5000]

Thank you both for the replies.
I have managed to get the cut where I wanted, though not too sure exactly how.
Installed the VOBU plugin. Tried to make the edit and clicked apply, though nothing appeared to happen. Was expecting some sort of confirmation but got nothing, so wasn't sure if the change had taken affect. Saved the DVD in PGCEdit then ran VTSFix from the tools menu. This then gave me an error saying it was unable to backup the vob file I had edited and stopped without fixing the last VOB file. Opened the DVD in VobBlanker but wasn't sure how to try and remove the edit I had made, but when I tried to cut the cell it now enabled me to select the last frame before the blank frames as the end cut mark. (Checked the unedited original DVD file ripped from the DVD but VobBlanker still wouldn't let me select the desired end cut mark in this file).
Anyway I have got the desired result, even if it was more from muddling through.

P.S. Am I correct in assuming that the first blank frame should be an I frame? If so then should VobBlanker allow me to select that as a cut point in the original ripped file?

[r0lZ]

The VOBU plugin changes only the pointer to the end of the cell in the IFOs. Nothing is changed in the VOB file. Although this method is not standard compliant, some players are happy and play the VOB cell up to the end pointer, and ignore the rest. You can see the change in the cell table of the PGC.
FixVTS cuts the cell at the position pointed to by the end pointer, or restore the original pointer in the IFO, depending on the options. I don't know exactly how VobBlanker handles the "wrong" pointer.

I don't know why you got the error with FixVTS, as, as I said above, the VOB file is not touched by the operation. Are you sure you have closed the preview?

The first frame of a VOB cell must be an I-frame, but the beginning of a sequence of black frames in a VOB cell doesn't need to be an I-frame. Each frame that you can see in the preview (of VobBlanker or PgcEdit) is an I-frame, and can theoretically be a split point. However, the minimal duration of a cell is fixed by the standard, and therefore it is not always possible to split a cell anywhere (but it should be possible to cut an arbitrary short part.)

[Bob_5000]

Thanks rolZ and blutach for info and help.
I have now managed to re-author the DVD successfully, without any blank frames or missing frames at the join point. Had a little problem trying to remux the DVD with IFOEdit, but a search of this forum told me I needed to fix the ac3 stream, then had a little issue of the subs being out of sync after the join, but re-synced the subs 1 cell at a time with DVDSubEdit. Now have the movie as one seamless DVD ready to be burned.