Can't read DVD [solved]

[neddie]

My Dad just sent me a DVD-RW, which he burnt using Windows XP. I loaded it into Mandriva 2007, and although it briefly span up, it wasn't recognised at all, and "ls /mnt/cdrom/" just gives the prompt. I tried manually mounting it with "mount /mnt/cdrom", and it said

/dev/hdc: Invalid argument
mount: I could not determine the filesystem type, and none was specified

Odd. So I tried this same disk in two different machines at work (one desktop, one laptop, both XP) and they both just said "please insert a disk into the drive" - nada.

 

By now assuming that the disk is really wonky, as a last resort I fired up XP on my machine (the one with Mandriva 2007 as dual-boot) to see if that read it - and surprise surprise it can! So I could copy the files off onto the hard drive, but I'm curious what's wrong with the disk, whether it's some wacky burn option or multi-session format or something? When I looked at the properties in XP it said "disk format: RAW" which sounded odd, but I'm not sure if it always says that for DVD-RWs... Thinking about it I've never tried DVD-RWs in this machine before...

 

Any clues what might be wrong? I'd be interested to find out how I could read it from Mandriva, but I'd be more interested in finding out what to tell my Dad so he burns it properly next time! ;)

[ianw1974]

I'd be tempted to do:

 

mount /dev/hdc /mnt/wackycd

 

of course, creating wackycd directory first. I've done this, just as a difference so that it doesn't attempt to read settings from the /etc/fstab file. Of course, it might still attempt, so maybe comment out the cdrom drive in the /etc/fstab first, just in case to make sure.

 

The above would then auto-detect settings for the cd, rather than use fixed settings from the fstab. Just an idea I had.

[dexter11]

Is that a movie? did you install libdvdcss?

[theYinYeti]

...I've been trying to get on MUB for the last 15 minutes, and I'm now waiting for my tab to display, so I might as well answer to this meanwhile :)

 

I'm not sure my answer is the right one. However, this makes me think of an "un-fixed" DVD.

Windows is able to deal with CD and DVD that are not fixed. Linux on the other hand, does not seem to be able to read those disks. And the process being highly un-standard, it wouldn't surprise me that the reading ability depends on the drive itself, thus making it a plug-and-pray issue on each Windows PC; for Linux, though, no amount of "pray" seems to do the trick.

 

This is something that bugs me a lot! Linux unable to do something that Windows can :shocked: There must be a way...

 

Yves.

[neddie]

...just as a difference so that it doesn't attempt to read settings from the /etc/fstab file.

But the only thing in my fstab is

/dev/hdc /mnt/cdrom auto umask=0022,users,iocharset=utf8,noauto,ro,exec 0 0

I'd be surprised if anything in there was causing problems, wouldn't you?

 

Is that a movie? did you install libdvdcss?

No, it's not a movie, it's just a DVD with family photos on it. I can read and write most CDs and DVDs I throw at it, and yes I've got libdvdcss and can watch my bought DVD films without problems.

 

There must be something strange about this disk, cos 2 other machines failed to read it too. I think YinYeti is closest with some kind of "fixing" or session-closing, I'll try to find out what program he used to make it.

[ianw1974]

Could be the utf8 thing causing the problem. Just in case it was burnt with some other setting. Just a thought.....

[neddie]

I put a # before the line in fstab, and tried the mount again:

# mount -t auto /dev/hdc /mnt/wackycd
/dev/hdc: Invalid argument
mount: block device /dev/hdc is write-protected, mounting read-only
/dev/hdc: Invalid argument
mount: you must specify the filesystem type

I also tried -t iso9660 just for a laugh, but with the same result.

[scarecrow]

Might be a rewritable made by windoze "Imapi burning engine".

Effectively this is an open packet writing disk, which can be read only under Windows XP or "better" and only if the reading device is a burner (a plain DVD-ROM will fail to read the disk). The software creates only udf structures (no ISO filesystem, no joliet and rockridge extensions) which are half-baked before closing the disk.

Under Linux such a disk can be read only if finalized.

Edited November 24, 2006 by scarecrow

[jaraeez]

Might be a rewritable made by windoze "Imapi burning engine".

Effectively this is an open packet writing disk, which can be read only under Windows XP or "better" and only if the reading device is a burner (a plain DVD-ROM will fail to read the disk).

 

This is a good point. If I burn a DVD on XP & leave it open it will not play on my DVD-ROM, but will play on my DVD-WRITER all in Mandriva (bloody took me ages to sus that one out ;) )

[neddie]

Interesting - the two other XP machines I tried it on do indeed only have DVD-readers, not DVD-writers.

But my Mandriva/XP machine only has one drive, which is a CD reader/writer, DVD reader/writer all in one. And still Mandriva can't mount it. I thought about comparing with another distro but my only alternatives are live distros, which occupy my only DVD drive!

[ianw1974]

You don't normally need to put:

 

-t auto

 

or anything, just do:

 

mount /dev/hdc /mnt/wherever

 

and it'll figure it out. At least it does when I've done it. If you want to pass options, you can use the -o parameter. This is all the stuff from the umask=0 and everything comma separated here.

[neddie]

just do:

mount /dev/hdc /mnt/wherever

Obviously that's what I did, until it said that I must specify a filesystem type.

# mount /dev/hdc /mnt/wackycd
/dev/hdc: Invalid argument
mount: block device /dev/hdc is write-protected, mounting read-only
/dev/hdc: Invalid argument
mount: you must specify the filesystem type

So then I specified auto and then I tried with iso9660.

 

Thanks for your help ian but I really think YinYeti and Scarecrow are on the right lines here.

[ianw1974]

I think so too, just was a thought in case it might help if wrong settings applied in /etc/fstab. Seems not though, ah well :P

[Guest darryl]

Hello,

 

I'm a newbie to Linux, so this is a guess.

 

Normally RAW defines a format used in digital imaging (along with TIFF, JPG, GIF, etc.). Each such format defines the degree of compression, if any, used, whereby you can select the "quality" of your photos when you take/store them.

 

And multiple degrees of compression may be available, depending on which compressed format is used.

 

The more compressed, the smaller the file, but subsequently the poorer quality of the image - and the more limited your options regarding modification. As you modify compressed files, their quality degrades. Think of a Xerox of a Xerox of a .... By the tenth copy, you may wonder what the original image was.

 

JPG files are compressed; RAW and TIFF are not.

 

Unlike compressed files, uncompressed ones do not degrade with each subsequent modification and save. If uncompressed, your options are literally unlimited.

 

Think in terms of using PhotoShop, etc. to manipulate a photo once you have saved an image. The software can modify a photo with better detail if you start out with uncompressed images (everyone uses the lens at the widest possible setting, saves the image in the smallest possible file, crops photos to the limit to simulate using a telephoto lens, and tries to squeeze out the last drop of pixels don't they???).

 

To illustrate how this translates to file sizes, Canon's EOS 20D instruction book shows a 256Mb memory card holds from 66 shots (3.6 Mb each using Large Fine JPG) to 380 shots (0.6 Mb each using Small Normal JPG), with four additional formats in between those.

 

If saving the images using RAW (8.7Mb each) alone, it holds only 27 images.

 

If saving RAW and JPG's simultaneously, it holds from 18 to 25 images.

 

Normally storage media can hold multiple kinds of files (JPG, RAW, TXT, CAB, EXE, etc) depending on the application. Just imagine a disk that can hold only one kind of file, i.e. only one extension type. How many CD's would it take to hold a typical Linux (or heaven forbid something from Redmond) application?

 

I believe you stated your problem showed RAW as the "disk" format.

 

If that "RAW" means the same as the RAW relating to digital images, I'm surprised they called it a disk format, because, as I understand it RAW defines files, but not the disk itself.

 

If you were just looking at the filenames, I believe they should have been displayed, unless the CD/DVD heads are malfunctioning. I say that, remembering the headaches created in our Commodore 64 days when one particular program made the heads bang against the stops several times before it would let you format a disk. After a while, it wouldn't read even its own earlier formatted disks.

 

Noting that RAW is a proprietory format, if you tried to load the file into a program, and for some reason the program wouldn't recognize the file, it is understandable that the application wouldn't load it.

 

I don't know just how manufacturers deal with letting the public view them with just any old file viewer, but viewers are available.

 

Check online for image viewers that handle RAW images and see if that solves the problem.

 

As an afterthought, since RAW is proprietory, don't be surprised if in at least some instances, manufacturer A's viewer is not compatible with manufacturer B's files (^&*(%*#()&$*()).

 

Best wishes,

 

Darryl

[AussieJohn]

Hello Darryl.

A great big welcome to MUB.

A big thank you for your debut post. Very enlightening indeed. I feel we will be hearing more from you in the future B) .

Cheers. John.

Edited December 5, 2006 by AussieJohn