unable to dd dvd

[JD]

On 04/29/2013 04:38 AM, Patrick Asselman wrote:
> On 2013-04-28 03:40, JD wrote:
>> Tried multiple dvd drives.
>> dd if=/dev/sr0 of=dvd.iso bs=2k
>> always results  in
>> dd: reading `/dev/sr0': Input/output error
>> 1+1 records in
>> 1+1 records out
>>
>> Tried on sr1, and sr2  all fail in the same way.
>>
>> And yet the movie plays just fine with vlc and smplayer!!
>>
>> This the first time I see this.
>> I never had this issue on Fedora.
>
> Could it be that the DVD is copyrighted and has intentionally corrupt 
> sectors on it?
> The media player simply plays the list of sectors given to it, so it 
> will never encounter those bad sectors, whereas dd will attempt to 
> read all sectors, so it will run into problems.
>
> Best regards,
> Patrick Asselman
>
>
What's somewhat interesting is that some movies I buy and back up using
dd have no problem at all. And some do, as I stated in my post.
I would have thought that all commercial movie dvd's sold in the US follow
the same method? policy? of production.
But I found a method to get around the problem.

Thanx,

JD