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

[JD]

On 9/24/19 8:14 AM, Ted Park wrote:
>> 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?
I should have mentioned that the resulting iso plays only partially,
that is: it (meaning VLC, mplayer, ffplay) play only the intro and stop.