Pauses at Chapter breaks

[rdkapp]

I'm having a little problem with pauses (on my SAP only) at a couple of chapter breaks in my homemade DVD. It plays fine on my computer drive. I've read in another thread that the STC (SCR) discontinuity (2) flag will not cause a pause, so long as the seamless joint (8) flag is ticked. However, this is exactly the situation on my DVD. It's only pausing at the beginning of Chapters 2 and 6 in Title 2, and those are the only cells which have both the STC (SCR) discontinuity (2) flag and the seamless joint flag (8) ticked (besides the tiny cell at the end), and that includes Title 1 also. Here's a screenshot of the PGC Editor for Title 2:



I wanted to remove the STC (SCR) discontinuity (2) flag, but I'm not sure what other effect that may have on my DVD, so I thought I would ask here first. Can anyone explain these pauses and why they only happen on the chapters that have the STC (SCR) discontinuity (2) flag ticked? Are there any solutions?

[blutach]

Please enlarge the screenshot. The pauses will be caused by the seamless flag not being checked (but you say they are). STC has to do with the system time clock and the mux. If the cells are not continguous and the time clock needs resetting, this can also cause a pause.

Regards

[rdkapp]

Please enlarge the screenshot.

Blu, I'm having trouble with posting a thumbnail screenshot that enlarges when the viewer clicks on it. That's what I thought I did last night. I used to use www.imageshack.us and it worked great, but they changed the interface and I'm having a time trying to figure it out. In the meantime, see the attached full size screenshot.

[r0lZ]

The STC discontinuity flag should not cause a pause, but since all cells are contiguous and have the same VOB ID, I guess you can remove them anyway. (Leave it only on cell 7.)
Then, play the DVD (preferably with several players) and watch the time displayed by the player when it jumps from chapter 1 to 2 and 5 to 6. If it changes abruptly, then you need to add the STC discontinuity flags again.

I wonder how you did this DVD, as it's a strange usage of the flags. Have you removed manually some cells and stripped them out of the VOBs with VobBlanker or Fix? Or have you concatenated several VOBs? How?

BTW, cell 7 is a tiny cell probably added to be able to jump to the end of the title by pressing Next on the remote, but, to work correctly, you need to add a program number in that cell. Just click on the first (empty) button of cell 7.

[rdkapp]

The STC discontinuity flag should not cause a pause, but since all cells are contiguous and have the same VOB ID, I guess you can remove them anyway. (Leave it only on cell 7.) Then, play the DVD (preferably with several players) and watch the time displayed by the player when it jumps from chapter 1 to 2 and 5 to 6. If it changes abruptly, then you need to add the STC discontinuity flags again.

Hey r0lZ, thanks for the response. I actually removed the STC discontinuity flags and tried to remap the time in PgcEdit, but there is still apparently a problem doing that, because it badly messed up the time. So, I then processed it through VOB Blanker to fix it, and it put the STC flags back in automatically. That's when I decided to ask here before going further.

I wonder how you did this DVD, as it's a strange usage of the flags. Have you removed manually some cells and stripped them out of the VOBs with VobBlanker or Fix? Or have you concatenated several VOBs? How?

BTW, cell 7 is a tiny cell probably added to be able to jump to the end of the title by pressing Next on the remote, but, to work correctly, you need to add a program number in that cell. Just click on the first (empty) button of cell 7.

The DVD is made up of 2 programs which I transferred from my DVR. They are 2 racquetball matches. I combined and converted them using FAVC, set for 10 minute chapters, and it just so happened that commercials ran through a couple of chapter breaks, and IIRC, it was those chapter breaks where the STC discontinuity flags are. So, when I cut the commercials in VobBlanker, it cut them over the chapter break, and apparently put the STC flags in at that time. The STC discontinuity flag in cell 7 is there because when I cut the commercial at the end of the DVD, it left a frame from the commercial and I found that the only way to get rid of that frame was to create a tiny cell and cut it over that cell break. Is there a better way of doing that, that won't result in the pauses/STC flags?

[Edit]: Actually, I think I split the commercial frame and then blanked it in VobBlanker, leaving the blank tiny cell. The navigation works fine, btw, but I will add a program number to cell 7 (I wondered about that). The only problems are those 2 pauses.

[r0lZ]

I see. It is strange that your player pauses at the cuts. Anyway, the STC flags are required, as the time stamps are not contiguous any more.

If you want to get rid of them, do clean frame-accurate cuts, and possibly create chapter points exactly where you want them, you should use the commercial programs Video ReDo or Womble MPEG Video Wizard DVD. They recreate the time stamps completely, so you should not need the STC discontinuity flags any more.

[rdkapp]

I see. It is strange that your player pauses at the cuts. Anyway, the STC flags are required, as the time stamps are not contiguous any more.

So, you're saying that I shouldn't even try removing the STC flags?

If you want to get rid of them, do clean frame-accurate cuts, and possibly create chapter points exactly where you want them, you should use the commercial programs Video ReDo or Womble MPEG Video Wizard DVD. They recreate the time stamps completely, so you should not need the STC discontinuity flags any more.

Would another option also be to set my chapter breaks in FAVC to where no cuts are necessary over a chapter break?

As always, thanks again r0lZ.

[r0lZ]

Yep, the STC flags are required, or you will have a discontinuity in the time displayed by the player, and maybe also some other annoyances. However, you can try to remove them, just to test if it's sufficient to avoid the pauses. Honestly, I don't think so.

You could try to remove the ads in the original AVI first, for example by copying it in direct stream copy mode with VirtualDub. (Do not re-encode it or you will lose quality.)
Another option is to use the scripts in FAVC to remove the ads from the video that is to be converted. It's possible, but you have to study how AviSynth work, and use the right syntax of the right filter!

[blutach]

I'd consider demuxing and remuxing. Or just "re-authoring" in something like Recode. That should fix up the timestamps.

Regards

[rdkapp]

You could try to remove the ads in the original AVI first, for example by copying it in direct stream copy mode with VirtualDub. (Do not re-encode it or you will lose quality.)
Another option is to use the scripts in FAVC to remove the ads from the video that is to be converted. It's possible, but you have to study how AviSynth work, and use the right syntax of the right filter!

I tried VirtualDub, but it "cannot detect the file type" of my avi files. I'm not sure why. Perhaps, its because I converted them from TIVO format? OTOH, I have no idea how to use scripts in FAVC. I briefly looked around for a guide, but couldn't find one.

I'd consider demuxing and remuxing. Or just "re-authoring" in something like Recode. That should fix up the timestamps.

blu, do I leave the STC discontinuity flags intact or remove them first? And, what exactly is demuxing and remuxing? I know about Muxman, but I've never used it except in conjunction with VobBlanker. Can you give me the skinny or point me to a guide on demuxing and remuxing?

@r0lZ and blu,

I figured that I can re-convert the avi files to dvd with FAVC, setting the chapter breaks to avoid commercials, but I'll have to do the 2 avi files separately, because they require different chapter break times. Unless there is an easier way, that is probably what I'll do.

[r0lZ]

Demux all streams (including the video strean, unticked by default) with PgcDemux. Remux with muxman. It's easy. Don't forget to import the celltimes.txt file in muxman to create the chapter points, and to verify thew audio stream delay with PgcDemux, and set it in muxman.
Of course, you can modify the celltime.txt file manually to move your chapter points where you want them. (It's only GOP accurate. That means that a difference of less than 0.5 second can occur.)

However, I'm not totally sure that will fix the time stamps in the stream themselves. I really don't know.

[blutach]

Muxman will certainly mux correctly and set the flags correctly (no user input is required - just add the streams). If the PTSs are messed up, however, there will be little that you can do.

Regards

[rdkapp]

While Remuxing with Muxman, I received the following error:

"Multiplex operation halted - Reference to non-existant scene "Segment_1_scn7" from PGC "VTS01_TTL01_PGC1"" (see attached screenshot)

Well, if it's not one thing, it's another. If I understand this error message, Muxman had a problem with the tiny cell/chapter (#7) at the end of the Title. What do I do now? Do I delete the cell/chapter, and if so, what about the navigation back to the Menu?

[blutach]

Delete the tiny cell - you can always add it back later if needs be. The nav depends on the commands that follow the end of the PGC (in this order) - cell commands (if any), post commands (these are usually present) and the NextPGCN link (this is not always present).

Regards

[r0lZ]

You can just delete the last line in Celltime.txt. Be sure to reload the file in muxman before processing.