Stupid question: what is Ifoupdate and what does it do? [Archive]

Arky

24th October 2002, 13:26

Err...if you open up the IFOupdate archive and read the :rolleyes: README :rolleyes: file...

You get this!:

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IFOUpdate V0.54

Purpose: This program was developed in support of CCE/IFOEdit method
of backing up DVDs. Please note the wording -- the tool is NOT intended
to be used as a tool for stealing copyrighted material. It is meant as
a way to LEGALLY create DVD-R backups of DVDs you have purchased.

The CCE/IFOEdit method is discussed (in a lot of detail, with also a lot
of supporting comments) here:

http://forum.doom9.org/showthread.php?s=&threadid=17400

As originally documented the CCE/IFOEdit method involved a pretty tedious
steps in which the person creating the backup had to manually copy (using
IFOEdit) numerous parameters related to cells. IFOUpdate was created to
automate that process. In fact you will find that when using IFOUpdate, it
often isn't necessary to use IFOEdit at all.

Thanks go to DERROW for his incredibly powerful IFO editing utility IFOEDIT
and to MPUCODER for his fantastic reference site. Together they have
managed to pull a lot of the secrets of the IFO out of the darkness and into
the light.

Here is a summary of IFOUpdate's program flow:

1. It backs up the original IFO to the backup directory.

2. If the option is checked (default) IFOUpdate copies the VTS_C_ADT table
from the new file to the original.

3. If the option is checked (not default) it copies the VTS_TMAPTI and
VTS_VOBU_ADMAP tables. Please note that care should be used in using this
option, in some DVDs copying this table can cause inconsistencies. I
added it to help fix a specific problem someone else was addressing, the
tables only appear to have an effect when a DVD is played back using PC
player software. I don't personally use it. There is also a "Dump" option
in which the table pointer is simply changed to "0" so players won't
misread the data.

4. It Loops through the VTS's PGCs. It uses the PGC count in the newly created
IFO as its loop counter. That creates a situation in which only the first
1-n PGCs are copied (sometimes when you use SpruceUp you can update only
the first PGC and ignore the rest). If "Maestro" Mode is selected the first
PGC in the Newly Authored is ignored (not counted). This is meant to help
users of Maestro get past the large "everything" PGC created by default as
the first PGC. For each PGC it:

a. Warns, but doesn't stop, if the number of Chapters doesn't match -- the
new IFO's chapter count becomes the reality. While it isn't required to
make the original and newly authored chapter counts match -- it is highly
recommended they do so the "Scene Selection" menus work properly.
b. Warns, but doesn't stop, if the PGC playback times don't match. The new
IFO's playback time becomes the reality.
c. If the Color option is checked (default) it copies the PGC's color
tables. This matters if you are have subtitles in your new VOB set.
d. Changes the number of programs in the original to match the number in
the new IFO.
e. Changes the number of cells in the original to match the number in the
new IFO. Note that this means you don't have to create a newly authored
file that exactly matches the original cell mapping. You have to keep the
number of cells less-than or equal-to the original though...
f. Copies the entire set of the program map, cell playback, and cell
position tables from new to original.
g. Corrects the Cell Playback Information Table Start Byte pointer to match
the new reality.
h. Corrects the Cell Position Information Table Start Byte pointer to match
the new reality.

-- Note any hard errors cause the backed up IFO to be restored.

5. When done with all PGCs, it updates the .BUP from the new .IFO file.

6. If the "Correct VTS Sectors" option is checked, it automatically goes through
all the IFO files in the set pointed by the "Original" path and corrects
sector offsets (much like the "Get VTS Sectors" button in IFOEdit).

You can also manually perform "Correct VTS Sectors" by pushing the button on the
main program's form.

Note: When Cell Only Mode is checked ignore everything above. The program very
simply loops through all the PGCs in the new IFO and copies cell information from
the Cell Playback Tables into the next sequential Cell in the original -- it
ignores the PGC structures involved.

Remember to always check DOOM9's site (http://www.doom9.org) when you want to get the
latest version. The site also has the best video forum you will find anywhere.

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I particularly like the last sentence, (although Flexion is pretty good too, when it's up and running!) :)

Arky ;o)