how to recover file from cd with gddrescue

I try to recover 2 movie on a dvd and I have gddrecue install and
I type this in terminal
dd if=/dev/sr0/Planetes_18.DVD(H264.AAC)[KAA][C67A83D0].mkv of=/dev/sda2/Planetes_18.DVD(H264.AAC)[KAA][C67A83D0].mkv bs=512 conv=noerror, sync
This is what the error message come out!
bash: syntax error near unexpected token `('

Any idea! Thank you!

First off, I cannot teach

First off, I cannot teach you how to use to command line. There are many ressources (who are much better than what I would be able to do) on the net.

Well, the problem is that you are typing characters in the filename that have meaning to the command line interpreter. You need to escape these special characters using the backslash symbol. Not to mention that you are trying to access /dev/sr0 as if it was mounted at /dev/sr0.

But it seems that this movie is a file on a data DVD? I think you would have an easier time just imaging the whole DVD and then copying the files off the image. Use gddrescue.

sudo gddrescue -vS /dev/sr0 image log

Then, mount the image and copy the files.

sudo mkdir mnt
sudo mount image mnt
ls mnt

I have two questions

I have two questions regarding the use of ddrescue for recovering data from bad cds.

First question --

Example 3, given at the ddrescue manual page http://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html#Examples

uses ddrescue twice for recovering data

ddrescue -n -b2048 /dev/cdrom cdimage logfile
ddrescue -d -b2048 /dev/cdrom cdimage logfile

Your suggestion above uses ddrescue only once. How do the two procedures differ in terms of result?

Second question --

Is there any point in running

ddrescue -d -r1 -b2048 /dev/cdrom cdimage logfile

for another pass? Assuming that ddrescue is reading from the same disc and not another copy on another disc?

Thank you,
PD

Hi PD. That's a good

Hi PD.

That's a good question.

The reason for using the -n flag is to get as much data from a failing device in as little time as possible. Instead of getting complete chunks of data, you are covering more of the disk, but leaving unfilled gaps. To me, the usefulness of this is to get as much data back from a failing hard disk before it stops putting out data at all. In some cases, it's just a matter of time.

In fact, when I power up a drive for data recovery, I always treat is as though it's the last time I will be able to get it up and running. That means I have everything ready to begin reading the drive.

It's not the same for an optical disk. If the media is corrupted - and I believe we will be seeing more and more optical disks fail in the future since the media may not always be the best choice for permanent data storage - it won't get worse as you attempt to read from the disk.

So I don't see the point in using the -n (don't split or retry bad areas) on an optical disk.

The -d flag is meant to use direct mode, which may be faster in some cases. Again, My experience with my equipment is that direct mode is much slower. However, on my (very old and reliable) equipment, I seem to be reading better at a slower rate in direct more in some cases. I usually try using the default settings and then play with the -d and -D options to adjust for speed and accuracy as needed.

One more thing about the -n flag - Gnu ddrescue automatically skips the bad areas on its first pass. Once that is done, it will go back and split/retry the bad areas. This is an intuitive way to go about it. And it's done automatically. Running specifically the -n flag and then completing the run by re-running without it makes no sense to me.

Andrew