Layer Break in Multi-angle VOBs ?

[Jiri Zita]

Hello all,

 

I have received one ISO+MDS image with multi-angle VOBs inside. ImgBurn cannot find a proper layer break in ISO image (in IFO). But our premastering software found a layer break at the same position as it is written in the MDS file. It seems that these ISO+MDS files were made (Read) from a pressed DVD and not with Built mode.

 

Have you any experience with layer breaks in multi-angle VOBs? And any theory behind it?

 

Jiri Zita

[LIGHTNING UK!]

If ImgBurn wouldn't accept the LB in the MDS file then it's because it splits the layers in a way that's not valid for OTP disc burning (i.e. L1 > L0)

[blutach]

And beware doing a LB in an angle cell. Although it should be legal, the interleaving will most likely get in the way and make for really awful playback. As a general rule of thumb, do not break in an angle cell. Reauthor the DVD, if necessary.

 

Regards

[Jiri Zita]

Hello,

 

and what do you think about following attached screenshot of large mounted ISO. It is taken from that problematic ISO image. Our software recommends to put the LB in the place of the yellow line - sector 2070432. Supplied MDS file (I don't know its origin) shows also 2070432, but according to ImgBurn in "Display IFO Layer Break Information" mode, there is none in VTS_16, VTS_17 and VTS_18. VTS_18 is their multiangle bonus clip. So who should I believe?

 

Jiri Zita

[blutach]

Do it at the start of any VTS, if possible.

 

If you can't find a good LB point, apart from splitting cells, you can remap the titlesets. Do this with PgcEdit. It's almost a one step process - just decide which VTSs should be in layer 0 and move them around.

 

Regards

[LIGHTNING UK!]

What does the disc info look like in the window on the right in ImgBurn with that MDS mounted? (copy + paste it all)

 

There must be *some* reason why ImgBurn doesn't think 2070432 is acceptable.

[Jiri Zita]

Do it at the start of any VTS, if possible.

 

If you can't find a good LB point, apart from splitting cells, you can remap the titlesets. Do this with PgcEdit. It's almost a one step process - just decide which VTSs should be in layer 0 and move them around.

 

Regards

 

Thanks for your suggestion, I think it will surely help and maybe I will try it in this case, but I have to ask the customer for confirmation to make this change in his supplied master. I cannot make any change without his written permission.

 

I really need to know if his ISO+MDS masters ARE wrong or NOT - for me not to be considered panic-monger

 

I have one more screenshot from analyzing of that ISO. I was told that every good layer break should have these "No previous VOBU" and "No previous possible VOBU" messages and here they are. I have no DVD+RW DL so I have to waste one or more DVD+R DL to check the behaviour of the disc in DVD player. I will post the playback results then ...

 

Regards,

 

Jiri Zita

[Jiri Zita]

What does the disc info look like in the window on the right in ImgBurn with that MDS mounted? (copy + paste it all)

 

There must be *some* reason why ImgBurn doesn't think 2070432 is acceptable.

 

MDS+ISO were probably created with Read mode directly from DL disc.

 

Mounted MDS info follows:

 

-----------------------------------------

UM7404C IMS525C 1.01 (ATAPI)

Current Profile: DVD-ROM

 

Disc Information:

Status: Complete

Erasable: No

Sessions: 1

Sectors: 3

[blutach]

Ask your customer - he probably couldn't care less if VTS 18 is on layer 0 or 1 and is swapped with VTS 19 for example. Another option is to move VTS 18 closer in on layer 0 (make it VTS 1 for example - this should create lots of breaks in what are now VTS 17 and below by the looks of the sizes of the VTSs).

 

Again - and even recognising that at the elementary stream level, everything in a mux is interleaved - if it were me, I'd not put a layer break anywhere near ILVU material. You just don't want the player going back and forwards across the break lots of times, just to play a single cell. This is especially so given your customer is unlikely to make the break seamless.

 

Anyway, from your picture, there should be the possibility of breaking at VTS_18_0.IFO, which is at 2,032,135, placing all of VTS 18 on L1. This is, by far, the best outcome.

 

Regards

[LIGHTNING UK!]

Layer Information:

Layer 0 Sectors: 2 070 432 (52,72%)

Layer 1 Sectors: 1 857 152 (47,28%)

 

I can't actually see a problem with that info.

 

Assuming your disc's layer break info is correctly recognised as:

 

DVD

[blutach]

Unless it's not a cell/ECC boundary perhaps (the latter is obviously OK)?

 

Regards

[LIGHTNING UK!]

The program doesn't even look at the image content if the MDS value is valid.