[mythtv] mtd: libdvdread vs libdvdnav

[Ed W]

Daniel Kristjansson wrote:
> On Wed, 2007-07-04 at 16:00 +0100, Bradley Kite wrote:
>   
>> I don't know specifically how RipGuard copy protection works 
>>     
> <snip>
>
> Presumably any DVD with "RipGuard" would also have CSS and
> so would probably be illegal to import into MythTV for most
> of the devs on this list. Hence we are unlikely to help you,
> and this does not pertain to MythTV development since it
> is _highly_ unlikely that a DVD copy protection bypass would
> be committed to the MythTV tree.
>   

I think the original poster phrased the request badly - please lets 
start again with something like the following:


"I wish to optimise the current DVD ripper to avoid copying unused 
chunks of the DVD.  The motivation is that we can potentially increase 
the ripping speed somewhat and decrease the space required to store the 
image by avoiding ripping parts of the disk which are empty.  Also it 
makes the ripping process more robust against certain types if damage 
and scratches by avoid trying to seek to parts of the disk which don't 
actually contain any data anyway.

The intention was to use libdvdnav to parse the disk and rip only the 
used parts of the disk, however, I am noticing that libdvdnav does not 
seem to be returning the disk data at full speed.  Can anyone suggest 
why this might be happening?"

Everyone happy?  This is nothing to do with copy protection, the issue 
is that many DVDs seem to be formatted larger than the size of the files 
on the disk, there is no need to copy the empty space and additionally 
we avoid any problems due to some of the unused space being corrupted or 
damaged (obviously doesn't help with scratches on the used part of the 
disk, but it should be a useful improvement on a number of disks that I 
have in my collection).

Ed W