Checksums don't match when using 32kb ifo padding

[roblov]

Hi,

 

i'm trying to burn a DVD i downloaded in a torrent. I've structured the DVD in the following way:

 

/

|---->AUDIO_TS (empty folder, created for compatibility reasons.)

|

|---->EXTRAS_TS (contains miscellaneous files)

| |

| |---->DVD 1.md5 (540 bytes)

| |---->HOP010_DG_2006-05-30_London_Home, Home Again.jpg (3.577.640 bytes)

| |---->info.txt (2.582 bytes)

|

|---->VIDEO_TS (movie)

| |

| |---->VIDEO_TS.BUP (8.192 bytes)

| |---->VIDEO_TS.IFO (8.192 bytes)

| |---->VTS_01_0.BUP (57.344 bytes)

| |---->VTS_01_0.IFO (57.344 bytes)

| |---->VTS_01_1.VOB (1.073.414.144 bytes)

| |---->VTS_01_2.VOB (1.073.414.144 bytes)

| |---->VTS_01_3.VOB (1.073.381.376 bytes)

| |---->VTS_01_4.VOB (1.073.397.760 bytes)

| |---->VTS_01_5.VOB (270.514.176 bytes)

 

That's the file structure of the DVD i want to burn. I followed the guide in this forum to the very last step. The DVD burns without problems. When i put the DVD in my drive and do a checksum verification with the md5 file shown above using Traders' Little Helper, i get the following message:

 

File 'E:\EXTRAS_TS\DVD 1.md5'

 

Line 001: file '..\VIDEO_TS\VIDEO_TS.BUP' failed verification (checksum does not match).

Line 002: file '..\VIDEO_TS\VIDEO_TS.IFO' failed verification (checksum does not match).

Line 003: file '..\VIDEO_TS\VTS_01_0.BUP' verified ok (checksum does match).

Line 004: file '..\VIDEO_TS\VTS_01_0.IFO' verified ok (checksum does match).

Line 005: ??? (process aborted by user)

 

There were errors.

 

Verifying checksums aborted.

 

I want to make clear that if i let the verification process reach its end, all files except for the first two shown above match perfectly. When i do the same with the files in my hard drive, i get the following message:

 

File 'C:\Documents and Settings\Roberto\Mis documentos\Mi música\David Gilmour\DG - 2006-05-30 - Home, home again - Royal Albert Hall, London (HOP 010)\DVD 1\EXTRAS_TS\DVD 1.md5'

 

Line 001: file '..\VIDEO_TS\VIDEO_TS.BUP' verified ok (checksum does match).

Line 002: file '..\VIDEO_TS\VIDEO_TS.IFO' verified ok (checksum does match).

Line 003: file '..\VIDEO_TS\VTS_01_0.BUP' verified ok (checksum does match).

Line 004: file '..\VIDEO_TS\VTS_01_0.IFO' verified ok (checksum does match).

Line 005: ??? (process aborted by user)

 

No errors occured.

 

Verifying checksums aborted.

 

Again, all the files not shown above match perfectly if the process is carried to its end. Trying to find an explanation for this, i found that if i disabled "32KB IFO padding" in the build options menu, all files from the burned DVD match perfectly, just as the ones in my hard drive.

 

So, my questions are these: why does this happen? what is "32KB IFO padding" exactly and why do checksums match in my DVD when i disable it? I'm sorry if these questions are a bit trivial but i'm a DVD newbie.

I'd like to point out also that, when "32KB IFO padding" is disabled, ImgBurn failed burning my disk once and, when it burned my disk correctly, the burnt "tracks" looked strange, not homogeneous as i expected but with different "intensities". I don't know if the term i use is correct but i can't find any other way to describe it right now.

 

All i want to do is make a copy of the torrent i downloaded that i can watch in my standalone DVD player (Sony NS-575P) which also contains miscellaneous files (artwork, info, and checksums files) so i can use it later for reseeding. I hope my objective comes through clearly. That's why i need all checksums to match.

 

Peace & thanks,

 

Roblov.

Edited October 5, 2007 by roblov

[LIGHTNING UK!]

The 32k padding will mean the files are modified (on the fly) to reflect the gaps (if any are actually needed).

 

So basically there's nothing to worry about.

 

ImgBurn's own verify is doing it at byte level so you're wasting your time doing it again.

[roblov]

The 32k padding will mean the files are modified (on the fly) to reflect the gaps (if any are actually needed).

 

So basically there's nothing to worry about.

 

ImgBurn's own verify is doing it at byte level so you're wasting your time doing it again.

 

Thanks for answering. There's one thing related to your answer that i don't understand, though. Should i trust my copy of the torrent to be an exact one even if the checksums for the files mentioned above don't match?

 

I'm sorry if this is the hundredth time you answer something like this but i've searched on the forum and nothing quite like this appeared. Since i don't know much about this (but i want to learn), some things are a bit difficult for me to grasp.

 

Thanks for your time, patience and efforts.

 

Roblov.

[LIGHTNING UK!]

Well if you're going to checksum something you'd do it before burning - to make sure the 'source' files are ok.

 

If it's different after the burn then the burning program probably had to modify something.

 

So long as the burning program can write + verify without giving any errors, the discs is perfectly fine.

[roblov]

Well if you're going to checksum something you'd do it before burning - to make sure the 'source' files are ok.

 

If it's different after the burn then the burning program probably had to modify something.

 

So long as the burning program can write + verify without giving any errors, the discs is perfectly fine.

 

I see your point. My point is that i want to preserve the original files unmodified along with their checksum files in case i want to reseed the torrent later on. People who trade music take special care to avoid modifying source material when it's not necessary. Also, the people who get this material from me might want to do a checksum verification, and if this modifications occur, those won't match.

 

Thanks,

 

Roblov.

[LIGHTNING UK!]

Well in that case you'd need to archive the files rather than burning a DVD Video disc.

[roblov]

Well in that case you'd need to archive the files rather than burning a DVD Video disc.

 

I'm going to try to burn the Video DVD without the ifo padding option and see what comes out of it again.

Thanks for your patience.

 

Roblov.

[LIGHTNING UK!]

lol that would of course get around the issue, but ONLY if everything else is ok in the files. It'll still correct the offset values if they're wrong.