2 Questions about making DVD-backupz.

[AirTimeDMC-12]

For some time now I have a dvd-burner, a NEC 1100a. I got a 2dvd-movie from a friend. This is the main movie of a dvd9 splitted into two. Stripped this movie is only 4,81gb. I don't want to spoil a second dvd on this movie, so I would like to rejoin the two dvdz and to downsample it so it will fit on one dvd.

This is what I did to rejoin them:

I renamed the VOB-files of DVD2 so they can be placed after the VOBz of DVD1.

DVD1:

VIDEO_TS.IFO
VTS_01_0.IFO
VTS_01_1.VOB
VTS_01_2.VOB
VTS_01_3.VOB

DVD2:

VIDEO_TS.IFO
VTS_01_0.IFO
VTS_01_1.VOB --> VTS_01_4.VOB
VTS_01_2.VOB --> VTS_01_5.VOB
VTS_01_3.VOB --> VTS_01_6.VOB

Then I copied the renamed VOBz to DVD1.

Now I have:

VIDEO_TS.IFO (of DVD1)
VTS_01_0.IFO (of DVD1)
VTS_01_1.VOB
VTS_01_2.VOB
VTS_01_3.VOB
VTS_01_4.VOB
VTS_01_5.VOB
VTS_01_6.VOB

In IfoEdit I stripped the movie as following:

http://home.wanadoo.nl/blanex/1a.gif

The new files were put in a new, empty directory


After that my new dvd looked like this:
(Click the thumbnails for a better view)

http://home.wanadoo.nl/blanex/1.gif (http://home.wanadoo.nl/blanex/1.jpg)

As you can see the chapters of what used to be my dvd2 are all gone.


Question 1: How correct this properly?

I do know a solutions through the 'Create Ifo'-option in IfoEdit. There are just a few flaws. You lose the information of the audio, subs and subcolors (and even more perhaps). To create new ifoz takes a much time a stripping the movie, in my case about 25 minutes.


Question 2: How to downsample a movie the correct way?

I am a little bit of a qualityfreak, so I want to know which is the best program to use if I wanted to downsample a movie. I doesn't matter how long it takes.