CDROM QnAs

can't mount music cd

Newsgroups: comp.os.linux.misc
Date: Tue, 25 Mar 2003 04:08:59 +0000

> I am unable to mount music CDs... I used fstype as iso9660... it works
> for data or even mp3 cds but NOT for normal music cds... is there a
> different fstype that goes with mount command?

You cannot 'mount' music CDs. They don't have a file system. mp3 cds ARE data cds (there is no difference between a mp3 cd and a data cd, except that the 'data' on a mp3 cd happens to be mp3 data files).

You have two options:

you use a cd player program (such as xmcd) to play the music
you use a 'ripper' program to copy the cdda tracks to wav files or something. I guess you can use dd to copy the music tracks as-is, which is only useful if you intend to burn them onto a new *music* CD-R.

can't mount music cd

> I am unable to mount music CDs...

There is nothing like iso9660 on a audio cd, but of course it is possible to write a file system driver which lets the tracks appear as files. See http://www.elis.rug.ac.be/~ronsse/cdfs/

Ralf

How to interpret cdrecord output?

Newsgroups: comp.os.linux.misc
Date: Thu, 20 Mar 2003 21:15:48 -0800

> How much data I can I write to a CD-ROM?

Go to http://www.google.com . Search for

CD-ROM sector size

The first result is http://www.disctronics.co.uk/technology/cd-rom/cdrom_spec.htm which contains the exact information you desire.

John Reiser

CD-ROM Specification

http://www.disctronics.co.uk/technology/cd-rom/cdrom_spec.htm

This page describes how data is stored on a CD-ROM in sectors with error correction to support many applications.

The CD-ROM specification ([24]Yellow Book) defines the use of two types of [25]sectors, mode 1 and mode 2. Mode 2 sectors are used for [26]CD-ROM XA formats. The main parameters of CD-ROM and CD-ROM XA discs are given in the table below.

Parameter	Value	Comments
Capacity	680 MB	Assuming 74 minutes
Raw data bitrate	1.41Mbits/s	Includes all bytes in sector
User data rate	150 kB/s	At 1x speed
Block (sector) size	2,352 bytes	Including header, ECC etc
User data per sector	2,048 bytes	With full error correction
Sector rate	75 sectors/s	At 1x speed
Sector Modes	1 or 2	See [27]Sectors
Sector Forms	1 or 2	[28]Mode 2 only

CD-ROM Sectors

Data stored on a CD-ROM disc is divided into sectors which are equivalent to the audio frames for a CD audio disc. At normal (1x) playback speed, 75 sectors are read every second. For double speed CD-ROM drives this increases to 150 sectors per second and so on. Seek times, while the disc rotates to the required starting position, will also reduce as speeds increase.

Because CDs were designed primarily for audio, their use for computer data requires the addition of header data and error correction codes which are included in every sector. There are two different types of sectors defined in the CD-ROM specification, [29]Mode 1 and [30]Mode 2 (the latter being used for [31]CD-ROM XA discs).

[32]Video CD discs use Mode 2, Form 2 sectors for the [33]MPEG video, allowing faster data rates (172 kbytes/sec instead of 150 kbytes per second).

Mode 1 Sectors

Mode 1 sectors are intended for the storage of computer data and contain the following fields.

Sync (12 bytes) which is used to enable the player to identify the start of each sector.
Header (4 bytes) consisting of Minutes, Seconds, Sectors and Mode (= 1).
ECC (Error Correction Code - 276 bytes), which comprises an additional level of [34]CIRC error protection.
EDC (Error Detection Code - 4 bytes) for detecting errors to be corrected.

Mode 1 sectors are the simplest type and are used for most CD-ROM based formats which follow the [35]Yellow Book.

Mode 2 Sectors

Mode 2 sectors are used for those formats based on [36]CD-ROM XA and can be either Form 1 or 2.

Mode 2 Form 1 sectors contain 2048 bytes with the same ECC as Mode 1 sectors.
Mode 2 Form 2 sectors contain 2324 bytes of user data per sector, with no ECC are are suitable only for data where errors can be concealed (eg audio or video data).

Mode 2 sectors comprise the following fields:

Sync (12 bytes) which is used to enable the player to identify the start of each sector.
Header (4 bytes) consisting of Minutes, Seconds, Sectors and Mode (= 1).
Subheader (8 bytes) contains content related parameters eg data type.
ECC (Error Correction Code - 276 bytes) which comprises an additional level of [37]CIRC error protection for Form 1 only.
EDC (Error Detection Code) for Forms 1 and 2.

Note that Mode 1 and Mode 2 Form 1 use the same error correction so can be used interchangeably, but not within the same track and preferably not on the same disc. Software used to write CD-Rs can be set for Mode 1 or Mode 2 Form 1. Almost all PCs and Macs will read Mode 2 Form 1 CD-ROMs as well as Mode 1.

Note that any CD-ROM will contain at least some Mode 1 or Mode 2 Form 1 sectors.

Capacity of a CD-ROM

The capacity of a CD-ROM depends on whether it is a [38]Mode 1 CD-ROM or [39]Mode 2 CD-ROM XA. Assuming the maximum size is 76 minutes 30 seconds (as recommended) this means that there are 336,300 sectors on a CD-ROM. From this must be subtracted 166 sectors at the start of track 1 plus a few sectors for the file system, amounting to, say, 200 sectors leaving 336,100 sectors for user data.

Mode 1 sectors contain 2048 bytes per sector giving a total capacity of 688,332,800 bytes or 656MB (where 1 MB = 1024 * 1024).
Mode 2 sectors contain either 2048 or 2324 bytes per sector so will have a somewhat higher data capacity depending on the mix of the two types of sector.

The above assumes a CD-ROM comprising a single track in a single session. For multiple track/session discs the data capacity will be reduced.

Disctronics Manufacturing (UK) Ltd.
       Copyright (c) 1999 - 2003

Any software to pull an .iso from a cdr or to compare an iso file with a cdr just burned?

Newsgroups:  comp.publish.cdrom.software,comp.os.linux.misc
Date:        Fri, 24 Oct 2003 09:46:04 +0200

> Any software to pull an .iso from a freshly burned cdr? Just thought I
> could pull the .iso and do an MD5 sum on both the pre burn and post burn
> to see if the burn was correct.

readcd

(if it fails, I doubt the burn was a proper one)

or just use diff :-)

Eric Moors

Any software to pull an .iso from a cdr or to compare an iso file with a cdr just burned?

> > Any software to pull an .iso from a freshly burned cdr?

I use 'dd if=/dev/cdrom of=outputfile bs=8k'. I find that the default block size for dd is rather slow.

> or just use diff :-)

diff is awful on very large files. And if you just want to know if there is a difference, 'cmp' is faster. It will stop when it finds the first difference and tell you how far into the file it is, but won't print the difference, good for binary files.

Elijah

Any software to pull an .iso from a cdr or to compare an iso file with a cdr just burned?

> Any software to pull an .iso from a freshly burned cdr?

Without it being mounted in Linux you can do it with "dd".

dd if=/dev/cdrom  of=slackware.iso

You can name it what ever you want since it gets the md5sum from the image.

David

Any software to pull an .iso from a cdr or to compare an iso file with a cdr just burned?

> You can name it what ever you want since it gets the md5sum from
> the image.

If you're just going to sum the image, why bother writing it to a file at all?

dd if=/dev/dvd | md5sum

I tried "md5sum < /dev/dvd", but apparently md5sum barfs on I/O errors, and dd doesn't (just complains).

On a related note, the files produced by "cat /dev/dvd > file1.iso" and "dd if=/dev/dvd of=file2" are 4096 bytes different in size (dd produced a larger file). Isn't the blocksize on a CD usually 2k? Why is there this difference?

Hactar

Help with "Special device /dev/cdrom does not exist"

Newsgroups: comp.os.linux.hardware
Date: 1999/12/24

> As the system boots or when I try to mount the CDROM, I get this message,
> "Special device /dev/cdrom does not exist. Return 32."

Probably you have a line like this in your /etc/fstab:

/dev/cdrom          /cdrom      iso9660    ro,user,noauto,unhide

which tells your system how to mount the cdrom. The /dev/cdrom file should be a sym link to the actual cd-rom device. You can create it like this:

# ln -s /dev/hdb /dev/cdrom

Here, hdb means the second ide drive in the first ide port, which you should change to the actual device your cdrom is in. If your cd is an IDE cd, it is one of hda, hdb, hdc or hdd; if it's SCSI, it will be one of scd0, scd1, … May be your cdrom is something special and you have to use a different device. You can see that looking at the booting messages (with "dmesg | more").

Once this is done, you can mount the cdrom with "mount /cdrom". In case you don't have the /etc/fstab stuff, you better add a line like the above. In any case, you can tell mount all the information in the command line. Eg:

# mount -t iso9660 /dev/hdb /cdrom

Jorge JUAN CHICO

Unable to mount cdrom

Newsgroups: linux.redhat
Date: 2002-12-14 03:20:36 PST

> I tried to mount my cdrom, however, after I typed "mount -t iso9660
> /dev/cdrom /mnt/cdrom" I found the following message come out,
>
> mount: special device /dev/cdrom does not exist

I suggest you run kudzu, which is a hardvare detector and should help you when you have new hardware installed on your system. If it don't help then you check up what the CD-Roms real device name is and use it instead of /dev/cdrom (which always is a symlink).

Most people choose to use the easy way and just type 'mount /mnt/cdrom', as the CD-Rom is usually part of the mountlist. But of course, there chould be problems if your CD-Rom drive is a USB device.

Aho

xcdroast tutorial

      Date: Mon, 09 Sep 2002 15:43:46 +0200
Newsgroups: comp.os.linux.misc

> It there a link to a good comprehensive "howto" for burning data cd's
> using xcdroast.  Although it is a good program, it is not the most
> intuitive interface for me.  I have been able to fudge through audio
> cd's with a little trial and error, but data cd's are a different
> matter.  Any help would be greatly appreciated,

I use the following link when I burn CDs with xcdroast: http://ccrma-www.stanford.edu/guides/planetccrma/mastering.html (the description is at the bottom of the page: it's not much text, but I never had problems using xcdroast with this description.)

Stefan Sollerer

cdrw (directcd software for RH)

      Date: 2 Oct 2002 09:12:49 GMT
Newsgroups: comp.os.linux.misc

> Does anyone know if there is packetCD or directCD software to
> rh?
>
> I would like to just mount the CD and tar to it. Without using
> burning software.

Certainly in the 2.4.18 and 2.4.19 kernel you just have to recompile with UDF support although it's considered 'dangerous'.

I'm not sure which kernel release already had UDF reading/writing available when released but according to the Packet-CD sourforget page (http://packet-cd.sourceforge.net/) some early 2.4 kernels needed patching for this functionality.

Lee J. Moore

packet writing on CDRW

Newsgroups: comp.os.linux.misc
Date: Mon, 04 Nov 2002 23:01:48 -0800

> I would like to get udf working with my cdburner.  I want to be able to use
> packet writing to mount the drive and use it.  I see that there is a patch
> for kernels pre-2.4.8.  I have the latest, 2.4.19 and was getting the
> impression from websearch material that the patch was merged.  Is this true?
> If so, where do I find that option in the config menu?
> thanks
> NR
>

Ahhh….I found this message in an archive (just had to do the right magic in google and ask on a newsgroup - always results in you finding the answer yourself shortly after :P) http://lists.suse.com/archive/packet-writing/2002-Aug/0083.html that complains about the sourceforge account not being active anymore :P The latest patch is here:

http://w1.894.telia.com/~u89404340/patches/packet/

it applies without flaw.

Now to get it working…

Noah Roberts