Converting DVD5 or DVD9 to ISO - is that (close to) lossless ?

[vhwul62]

I have a number of DVD's on HDD (containing .vob files, etc.) and like to convert those to .iso files.
(with e.g. ImgBurn or DVDFab)

Curious to know...:
will there be any loss of quality, or will the quality be the same, or at least very close to the same, i.e. no noticeable difference.

Oh, btw, I have done a test as to convert a DVD to .mkv using MPEG-2 video stream format (not H.264/AVC).
This resulted in a 4GB file (source was/is 4.6GB)
However, when using H.264 x264 it would result in something like 1.4-1.7GB

So, if space isn't important, I guess MPEG-2 is to be preferred (in case of .mkv).
This is a bit off-topic, I know.

The question was about converting to .iso.

Thanks!

[netmask56]

If you simply wrapped the original DVD in a MKV container using MakeMKV, there is no loss or no change in size. So if source is 4.6GB for the whole disc then the resulting MKV files of all the titles on the disc will total 4.6GB approx.

[LigH.de]

You do not "convert" a DVD to an ISO file; the ISO file is an image of the whole media content, files (VOB, IFO, BUP) as well as the file system (in case of a Video DVD, both ISO-9660 and Micro-UDF) including a directory structure – sector by sector, as if it were burned or pressed onto a physical disc. The file contents will be preserved byte-exact. Thus, quality cannot be degraded.

In addition to the ISO image (especially if you have a DVD-9 with layer break), ImgBurn will also create an MDS file describing the track layout (possibly including the position of the layer break, very important for a DVD-9).

You may then mount this ISO (or MDS) file in a virtual CDVD drive, like e.g. Daemon Tools, and it will appear to the system like you would have inserted a physical disc into a real drive.

[vhwul62]

Many, many thanks to you both! All clear. Will check out MakeMKV as well.
Again thanks!!