[FFmpeg-user] [offtopic] expansion of video content

[Ted Park]

> At anyrate, I use dd to copy the dvd to HD.
> On HD, the size of the iso file (after copying SOME dvd's)
> is in excess of 20GB. such as 22GB+, 26GB+...etc
> 
> Could someone explain why this is?
> 
> I thought dvd's have capacities of 4.7GB, 8.9GB for double density.
> I also know about dvd's that have slightly more than 10GB capacity.

dd doesn’t know about any of that. Your dvd drive might handle the copy protection in a way that causes this, or it might be the driver (did you use srX or dvd device? Might not matter)

Usually you determine how many blocks you want and the block size, using isoinfo for example, before you dd from a cd/dvd drive so you know how big the image is going to be before you start. But your case is interesting, more often you’ll get a smaller file when content scrambling is the culprit due to the read erroring out along the way, is the resultant image file usable?