FAQ: Burning with ImgBurn vs Nero - which is better?

[blutach]

Burning with ImgBurn vs Nero - which is better?

This is the scoop on Nero vs ImgBurn burning stuff. To fully understand this difficult subject, read this post and the one 5 posts down.

Now, the facts:

• Your standalone needs the UDF file system (old ones tend to work only with version 1.02, modern players can usually work with newer versions).
• Your PC needs the ISO file system. If you have a modern operating system, it can probably read UDF too (XP, 2000 and ME read UDF natively - Windows versions before these need a UDF reader installed)
• AFAIK, ImgBurn (and I guess DVD Shrink) creates an ISO image which contains an ISO9660/UDF 1.02 "bridge" file system (to be compliant with DVD standard).
• I have heard that, at least in early releases of Nero 6, Nero's implementation of "DVD-Video" was not compliant with this specification (it used UDF 1.05 - not sure of what's implemented there now). Nero's ISO/UDF bridge would appear to be compliant, as the user can actually select UDF 1.02.

The upshot of this is, if you want to burn with Nero and have total confidence that your burn will be totally compliant (at least in respect to the file system), in all standalone players, you can select UDF 1.02 or the DVD-ROM (UDF/ISO) and on the UDF tab, select 1.02 file system.


But there's more!!! (courtesy of the great mpucoder)

There can be gaps on a DVD. The most notable ones are those used to ensure that no ECC block contains any portion of an IFO file and its associated BUP file. Since ECC blocks are 16 sectors long (32K), the easiest way to accomplish this is to ensure that there are 16 sectors between the end of the IFO and the start of the BUP. With VIDEO_TS.VOB or VTS_xx_0.VOB files less that 32K (or absent) this means using a gap.

Burning programs handle this in one of three ways, two of which are correct.

• They can honour the authoring program's layout and place the data on the disk according to the pointers in the IFO files.
• They can make their own layout decisions and alter the pointers accordingly.
• They (notably Nero) (at least in several past versions) pack the data as closely as possible and ignore the pointers.

The upshot of this is, in order to maximize the chance of a "good burn", to use ISO images. Burners don't examine the data or the layout of an ISO image, they just burn it. Even Nero can apparently handle them OK. But why bother when ImgBurn is there?

EDIT: For the definitive answer to this vexing problem refer to http://forum.digital-digest.com/show...578#post222578 (5 posts down)

[r0lZ]

Good explanation, blutach.

Unfortunately, DVDShrink DO NOT leave a gap between the IFO and the BUP: it places them as near as possible.

I have tried to make the ISO with ImgTools Classic, but the result is the same: no gaps at all.

If I manually change the pointers in the IFOs, the result is not better: the files are also placed side by side, with both DVDShrink and ImgTools. [EDIT: Wrong: ImgTools Classic (but not ImgTools Burn) works well, respecting the gaps]

So, the gaps theory is fine, but seems that there are no burners/ISO makers able to handle them... [EDIT: Wrong again: ImgTools Classic and RecordNow MAX are able to burn DVDs with gaps, and PgcEdit v0.4.8 will also]

[blutach]

Well hi there mon ami rolz!!

My understanding is that the order of items in a VTS on the physical disk is IFO - VOB(s) - BUP. This was the thinking behind my post to you at doom9 to ensure the VOB of a blanked title is at least 32k, not 10k.

So, if the VOB is 32k already, there should be no problems. But if not, DVD Shrink users burning with Nero could run into problems with Nero's file allocation. mpucoder seems to think that Nero's current allocation is OK, but he was not complimentary about the fact that this has varied from right to wrong a lot in the past.

If what you say is right about image creation, then we better hope that we never need to access a BUP!

Regards

[r0lZ]

Here is the explanation of the test I've done. I have made a DVD with a serie of VTS with a simple frame in each titleset. The structure of the directory is:

VIDEO_TS.IFO 20 KB
VIDEO_TS.BUP 20 KB
VTS_01_0.IFO 12 KB
VTS_01_1.VOB 12 KB
VTS_01_0.BUP 12 KB
VTS_02_0.IFO 12 KB
VTS_02_0.VOB 14 KB
VTS_02_0.BUP 12 KB
...

Then, I have generated an ISO with DVDShrink and another one with ImgTools Classic.
Then, I loaded the ISOs in an hexadecimal file editor. Both ISOs are almost identical (except the ISO headers).
I have searched for "DVDVIDEO-VMG" and "DVDVIDEO-VTS", which are the first bytes of the VIDEO_TS.IFO/BUP and VTS_XX_0.IFO/BUP, and noted the addresses:

VIDEO_TS.IFO A2800
VIDEO_TS.BUP A7800 
VTS_01_0.IFO AC800
VTS_01_1.VOB
VTS_01_0.BUP B2800
VTS_02_0.IFO B5800
VTS_02_0.VOB 
VTS_02_0.BUP BC000

As you can see, VIDEO_TS.BUP begins exactly 0x5000 (20480) bytes, ie 20 KB after the beginning of VIDEO_TS.IFO (and VTS_01_0.IFO begins also 20 KB after VIDEO_TS.BUP.)

VTS_01_0.BUP begins 0x6000 (24576) bytes after VTS_01_0.IFO, ie 24 KB, which is the size of the IFO + the VOB.

VTS_02_0.BUP begins 0x6800 (26624) bytes after VTS_02_0.IFO, ie 26 KB, which is the size of the IFO + the VOB.

Obviously, there are no gaps to ensure there are at least 32KB between the IFO and the BUP. Pitty!

[blutach]

Obviously a potential problem

I thought DVD Shrink used the ImgTools Classic algorithm to generate images, so no real surprise that both give the same results.

We need to explore this more. Rather than clog up this FAQ, the conversation seems to be taking shape in your thread at doom9.

Digital Digest members - I will post any further updates as they become due.

Regards

[blutach]

Finally!!! -- The Solution To This Burning Mess


If you have followed this FAQ so far, you’ll know there’s an issue with “small titlesets”. DVD Shrink and Nero can not fix this – even when creating an ISO, since they pack the data as closely as possible.

For those of you with VOB files in a titleset totalling less than 32K (including and especially VIDEO_TS.VOB), a solution to this issue has just been developed.

Not surprisingly, it does not involve Ner0 (or any other commercial software).

This problem does not affect disks which have VOBs for each titleset totalling 32K or more. However, crucially, it does affect ALL reauthored disks.

______________________________________________


Let’s start with an example:

Suppose you had a DVD after shrinking that looked like this:

VIDEO_TS.IFO	20k
VIDEO_TS.BUP	20k
VIDEO_TS.VOB	0k (you often see 0 byte files on DVDs or no VIDEO_TS.VOB at all)

VTS_01_0.IFO	86K
VTS_01_0.BUP	86K
VTS_01_0.VOB	38,000K
VTS_01_1.VOB	1,048,574K
VTS_01_2.VOB	1,048,574K
VTS_01_3.VOB	1,048,574K
VTS_01_4.VOB	1,048,574K
VTS_01_5.VOB	200,000K (this titleset is obviously the main movie)

VTS_02_0.IFO	12K
VTS_02_0.BUP	12K
VTS_02_1.VOB	20K (this might be the original – just a second of blackness or you might have inserted a "still image")

VTS_03_0.IFO	60K
VTS_03_0.BUP	60K
VTS_03_0.VOB	500K
VTS_03_1.VOB	140,000K

Now, if you have followed the dialogue above, you will know that problems can be caused if there isn’t 32K between the end of the IFO and the beginning of the BUP (files are stored in the order of IFO – VOB(s) – BUP).

This isn’t a problem for VTS_01 and VTS_03, but VIDEO_TS and VTS_02 are in trouble.

Click here for an updated guide on how to fix this by burning with PgcEdit and ImgBurn.

P.S. Please direct questions in the Blank Media & Burning forum, not as a response to this FAQ.

P.P.S. (Had to get some blue in somewhere, didn't I?)

[jmet]

This thread has been closed/locked, as it is for information purposes only. If you have a question regarding this thread. Please start a new thread in the DVD Shrink - General Discussions sub-forum.

Thanks,
Moderators of the FAQ/Knowledgebase forum