DL, Layer Break, et al

GParent · January 20, 2006

The more I read about Dual Layer, Layer Break, and how they work, I have more questions. I am unsure of the Layer Break code and who has responsibility for plaing it in a video file. Based on my limited understanding, the builder of the DVD (eg. commercial movie) is responsible for placing a LB code in a VOB file at a stratgic place where the delay between Layer 0 and Layer 1 is not annoying to the person watching the movie. IMHO, this would ideally be between cells (chapters). However, it can technically be any where that meets the DVD standards for LB placement.

Does IMGBURN insert a LB code on the DL DVD?

If yes, how does IMGBURN go about inserting a Layer Break into a Dual Layer DVD?

Do you have to strategically place one Layer Break code manually in a VOB file, if the original LB code has been stripped out by another program?

What if there is no Layer Break code in any VOB, how does IMGBURN handle the Layer Break?

Thanks,

Gary

**LIGHTNING UK!** · January 20, 2006

As ImgBurn doesn't (yet) create images from files, it's not really its job to make/set/align the layerbreak position.

The thing people generally assume to mean 'layerbreak' is just a flag in one (or more if their LBA is the same) of the cells mentioned in the IFO. There is nothing in the vob to signal where it is.

ImgBurn will parse the filesystem and look for vob files that lay with the acceptable LBA range. ie. the middle LBA of the file (minimum) and the original layerbreak on the media (before it's changed - that's the maximum).

If it finds a vob between these points, it will read its associated IFO file.

It then looks through all the PGCs within those IFO files to see if any of the cells are already marked with the 'I'm a layerbreak' flag.

If it finds one, it add it to the list of potential layerbreak positions.

If it scans all the cells and none are marked with the flag, it checks them again to see if they start on an LBA thats a multiple of 16. These then become a potential position for the layerbreak and are added to the list.

Once that's all done, the list will hopefully contain a few potential positions. If it doesn't, the user is warned of the dangers of burning the disc. If it's not empty, the list is displayed to the user in a dialog box (if there is more than 1 option). They can then choose which one they want to use.

If the selected position didn't have the flag set, ImgBurn sets it.

Burning then continues.

Of course none of that needs to happen if the user is burning from an MDS file where the layerbreak info is already contained within it.

GParent · January 20, 2006

>> If the selected position didn't have the flag set, ImgBurn sets it.

>>Burning then continues.

>> Of course none of that needs to happen if the user is burning from an MDS file where the layerbreak info is already contained within it.

By the last statement, I assume you mean that IMGBURN was used to create an ISO file of the original DVD and therefore, has a MDS file with the specifics of what was just created, and then a duplicate could be pproperly copied onto a DL media.

What about a scenario where a program like DVDSHRINK were used to strip out subtitles and audio files and maybe a few titles being reworked. The output size would still be over one layer. This would essentially change the sector positioning as it was from the original DVD. Then, DVDSHRINK would strip the original LB flag. In that case, can I use IMGBURN to add a new LB and properly burn the image.

NOTE: Based on your reply I would say YES, but I would love a confirmation or please point out any errors in my thinking.

Incidentally, you're the only one on planet earth who even responed to my questions. Thanks for that.

Gary

**LIGHTNING UK!** · January 20, 2006

Incidentally, you're the only one on planet earth who even responed to my questions. Thanks for that.

Well I'm the only one who'd know the answer

Going back to your questions....

ImgBurn doesn't create ISO files. It can't read anything. If another program was used that creates proper MDS files, yes the layerbreak position will be retained.

If you reauthor a disc and it's done by a program that's not layerbreak aware (i.e. DVDShrink), you'll be lucky if the ISO it creates will be compliant for DL burning.

The odds of it just happening to start a new cell on a LBA that's a multiple of 16 are pretty slim.

ImgBurn cannot move the files within the ISO so if they're not right in the first place, you're stuck.

In such situations, you're better off writing a video_ts folder and using PgcEdit to create the image.

PgcEdit will ensure the image DOES have a cell that can be flagged as the layerbreak one and it WILL start on a sector (LBA) that's a multiple of 16.

grampaw · January 21, 2006

I'd like to share my experience using Shrink to reauthor, then ImgBurn to burn a DL disk where the resulting ISO doesn't have an associated MDS (i.e. - no LB is specified). ImgBurn never gives me any dialog box for choosing - it just sets the LB point, says it did that, and then burns the disk. BTW, neither DL burner I use is bookmarked DVD-ROM - and I use DVD+R media (either RIDATA or Verbatim) burning at 2.4x.

What are the results? Well based on the five or so I've burned this way, they are all playable on stand-alone DVD players (haven't tried a computer DVD-ROM). How well they play seems to depend on the player. On the Pioneer player, I usually either get a hesitation of maybe 2 or 3 seconds at the LB, or sometimes it will just freeze. A quick hit on the remote FF button gets you past the freeze. On the Toshiba player, I get a maybe 1 second hesitation in all cases and that's all.

I assume the player FW sees the LB, then sees an error, and then does whatever error-correction it's supposed to do. This is all acceptable to me - I'm not looking for perfection I guess.

I'll have to experiment with the PgcEdit technique - I wasn't quite sure what the purpose of that app was.

**LIGHTNING UK!** · January 22, 2006

Oops, yeah sorry, I'd added a warning to the manual check of the layer break - via Tools -> ISO -> Display IFO Layer Break Information, but I'd left the real burning routine to just revert back to the old method of searching the vob for a nice (ish) place.

I've now added one to the actual burning bit too.

GParent · January 24, 2006

I am soaking up your perals of wisdom here.

I am investing a half-dozen DVD+R DL Verbatims to experiment and learn how to do this properly. So far, the best formula is:

PGCEDIT - LB Identifier

IMGTOOL - ISO creator

IMGBURN - Write and Verify DL Disc

That group of programs gets the job done, and I am confident the final result will be spot on!

First, a couple of quick questions to you LIGHTNING UK:

(1) Does IMGTOOL CLASSIC create a MDS file that PGCEDIT pases to IMGBURN?

(2) Which Program puts the LB flag, that you select in PGCEDIT, into the appropriate IFO file?

(3) Is there a way to have IMGBURN automatically process the ISO file after PGCEDIT calls it upon completion of IMGTOOL CLASSIC?

Lastly, during my experimenting I did backup a DVD after some VOB BLANKER trimming. In addition, the original LB was removed by CLONEDVD2 and I burned it with COPYTODVD. However, using IFOEDIT I could not find a LB flag in the IFO file. Yet, I was able to play the DVD and it seemed to burn without a hitch. At the time, I thought COPYTODVD was going to do what PGCEDIT can do. Apparently, its not capable of generating new LB flags.

Why does it work with no LB flag in the IFO file? I was able to navigate forward and backward with no hangs. I have read where the LB flag is only needed to do backward navigation from Layer 1 to Layer 0. Any thoughts?

**LIGHTNING UK!** · January 24, 2006

Not all players need the LB flag. It's the playing through the LB that causes a problem, I not so sure if 'jumping' (FF / Rewind) over it would do.

PgcEdit insert the LB flag.

PgcEdit just uses the mkisofs file from ImgTool Classic, that's all.

ImgTool Classic itself is never used / called up.

PgcEdit can be told to load ImgBurn and start burning the ISO file. The LB position you select in PgcEdit is passed via a command line parameter to ImgBurn.

Neither of those programs create an MDS file.

**lfcrule1972** · January 25, 2006

If you reauthor a disc and it's done by a problem that's not layerbreak aware (i.e. DVDShrink)

Snigger ha ha :lol: BWAHAHAHAHAHAHAHA =))

And you can be so nice about other peoples programs.....

**LIGHTNING UK!** · January 25, 2006

Oops, corrected

GParent · January 25, 2006

So all I need is the following program, instead of IMGTOOL?

http://www.andante.org/mkisofs.html

Can I assume that the following scenario is the proper big picture of the flow you have detailed?

After some user interaction to select a LB, PGCEDIT modifies the specific IFO file, for the VOB set that contains the LB. Then, calls MKISOFS.EXE in which it takes the IFO, BUP, and VOB files and creates an ISO image. Finally, PGCEDIT calls IMGBURN, without giving you the MDS file. But you scan the ISO file and locate the LB flag inside the IFO file and burn the DVD.

As a suggestion, if the last sentence is true, it would be nice if PGCEDIT were to give you information that would negate the necessity to search for the LB, FWIW!

Thanks,

GParent

P.S.

You have started a quest for me to learn more about Layer Break and what DVD Players do with or without them.

**LIGHTNING UK!** · January 25, 2006

No, you don't need any old mkisofs, you need ImgTool Classic's mkisofs. It has been modified slightly.

Searching the IFO's takes a fraction of a second!

but in any case, re-read my previous (ignoring the 1 liner!) post

The LB position you select in PgcEdit is passed via a command line parameter to ImgBurn

ImgBurn doesn't search for the LB position when that happens.

rew · January 30, 2006

If you reauthor a disc and it's done by a program that's not layerbreak aware (i.e. DVDShrink), Correct me if I am wrong but if imageburn could burn in file mode you could automatically insert a correct layer break such as discjuggler and vso which is extremely handy when creating reauthered discs . is the layerbreak issue due to the fact we are burning an image file and cannot be manipulated during the burn process

**LIGHTNING UK!** · January 30, 2006

Yes, that is correct.

If/when ImgBurn lets you burn from a bunch of files, dealing with the layerbreak will be easier. An image file is very restrictive when it comes to positioning the layerbreak and lining things up properly.

raddad · February 11, 2006

Not all players need the LB flag. It's the playing through the LB that causes a problem, I not so sure if 'jumping' (FF / Rewind) over it would do.

PgcEdit insert the LB flag.

PgcEdit just uses the mkisofs file from ImgTool Classic, that's all.

ImgTool Classic itself is never used / called up.

PgcEdit can be told to load ImgBurn and start burning the ISO file. The LB position you select in PgcEdit is passed via a command line parameter to ImgBurn.

Do I need to burn the ISO right away?I usually close PgcEdit and Burn the image later.Would that cause a problem?

in2deep · February 11, 2006

I'm trying to decipher this conversation, but some of it is over my head. I'm trying to get my first DL burn to work with no success. I'm creating my .MDS file with ImgTool Classic and trying to burn to my new Plextor PX-704A (fireware 1.02) using Verbatim +R DL and ImgBurn (with default settings).

So far I have 2 nice costers, but that's it.

From what I gather from this thread, I shouldn't have to worry about the layer break if using ImgTool Classic, but not 100% positive.

Can some one please confirm and maybe point me in the right direction.

Here my last log:

I 20:42:09 ImgBurn Version 1.1.0.0 started!

I 20:42:09 Microsoft Windows XP Professional (5.1, Build 2600 : Service Pack 2)

I 20:42:09 Initialising SPTI...

I 20:42:09 Searching for SCSI / ATAPI devices...

I 20:42:14 Found 2 DVD?RWs!

I 20:42:35 Operation Started!

I 20:42:35 Source File: C:\Documents and Settings\Mike\Desktop\FLT0NNW1.MDS

I 20:42:35 Source File Sectors: 4,038,720 (MODE1/2048)

I 20:42:35 Source File Size: 8,271,298,560 bytes

I 20:42:35 Source File Application Identifier: GEAR UDF Application

I 20:42:35 Source File Implementation Identifier: GEAR UDF

I 20:42:35 Destination Device: [1:0:0] PLEXTOR DVDR PX-740A 1.02 (D:) (ATA)

I 20:42:35 Destination Media Type: DVD+R DL (Disc ID: MKM-001-00) (Speeds: 2.4x, 4x, 8x)

I 20:42:35 Destination Media Sectors: 4,173,824

I 20:42:35 Write Mode: DVD

I 20:42:36 Write Type: DAO

I 20:42:36 Write Speed: 4x

I 20:42:36 Link Size: Auto

I 20:42:36 Test Mode: No

I 20:42:36 BURN-Proof: Enabled

I 20:42:36 Optimal L0 Data Zone Capacity: 2,051,248

I 20:42:36 Optimal L0 Data Zone Method: Copied From Original Disc

I 20:42:36 Filling Buffer...

I 20:42:39 Writing LeadIn...

I 20:42:50 Writing Image...

I 20:42:50 Writing Layer 0... (LBA: 0 - 2051247)

W 20:51:44 Failed to Write Sectors 1371200 - 1371231 - Write Error

W 20:51:44 Retrying (1 of 20)...

W 20:51:44 Retry Failed - Invalid Address For Write

W 20:51:44 Retrying (2 of 20)...

W 20:51:44 Retry Failed - Invalid Address For Write

W 20:51:44 Retrying (3 of 20)...

W 20:51:44 Retry Failed - Invalid Address For Write

W 20:51:44 Retrying (4 of 20)...

W 20:51:44 Retry Failed - Invalid Address For Write

W 20:51:44 Retrying (5 of 20)...

W 20:51:44 Retry Failed - Invalid Address For Write

W 20:51:44 Retrying (6 of 20)...

W 20:51:44 Retry Failed - Invalid Address For Write

W 20:51:44 Retrying (7 of 20)...

W 20:51:44 Retry Failed - Invalid Address For Write

W 20:51:44 Retrying (8 of 20)...