Some surprise while "dd-ing" a video DVD...

[Andrea Giuliano]

J.Markoll wrote:
>>What did "mplayer" do that allowed "dd" to work?
> 
> Why do you want to attribute the better result do mplayer ? no sense to 
> that.

I definitely agree with you, it's mystic, but it works. Why? I don't 
know. Why mplayer? I know this one: I just tried with it, and the next 
test will be with another DVD player. Would you bet on the result?

> I also get regularly awful I/O errors on diverse operations with the CD 
> and DVD devices, be it burning, or else, such as ripping, but there is 
> no clue till here. It's mystic, I was advised to put garlic on the 
> machine :rolleyes!:

I prefer garlic with olive oil on spaghetti, but I will give a try to 
your suggestion anyway.

Seriously, I get the same error in many other circumstances, but this is 
a quite particular situation: sometimes the disks are not clean, 
sometimes the drive quality is rather poor... but this time the only 
difference I see is that every clean, well burned and scratch-free data 
DVD can be dd-ed without problems on my drive, while the only way to 
accomplish the same with video DVDs is following the above mystic receipt.

BTW, try to copy a video DVD with Nautilus/Copy Disc: I always get the 
"No media available" error message, while it never happens with data 
DVDs. I don't know if this has some relationship with the subject.

> 
> 
>>You have to know that:
>>1) all this happens with several different video DVDs;
>>2) the DVD drive is rather new (August 2005);
>>3) the disks work perfectly on my DVD player (I mean, they are original, 
>>not copies, they are clean, they have no scratches, and so on)
>>4) I run Breezy, updated.
>>
>>Best regards.
> 
> If someone has clues, or if you find out what the trouble comes from, 
> I'd be
> most interested, as I did search quite long, with diverses graphical 
> frontends, with tools in the shell, and on the web too.

Don't tell me about that! I've been spending several evenings this way, 
and never found anything...

(CD and DVD are
> close cousins, aren't they ?)

I used to think so. Usually, you can simply mount a video DVD as an 
ISO9660 filesystem. Then you can crawl in it anyway you want. I've 
always thought that VOB files are encrypted, but not the ISO image. In 
the latter case, it would be impossible to mount the DVD, I guess.

Anyway, thanks for your reply.

> Greetings, Joyce Markoll.
> 

-- 
Andrea Giuliano, Ph. D.
ICCU - Istituto Centrale per il Catalogo Unico
Viale Castro Pretorio 105, Rome - ITALY
Tel. +39 06 49210403, Fax +39 06 4959302