303 lines
13 KiB
Plaintext
303 lines
13 KiB
Plaintext
--------------------------------------------------------------------------
|
|
cdrskin Wiki - plain text copy
|
|
--------------------------------------------------------------------------
|
|
[[Image(source:/libburn/trunk/cdrskin/doener_150x200_tr.png)]] [http://en.wikipedia.org/wiki/D%C3%B6ner_kebab Doener]
|
|
|
|
'''cdrskin is the cdrecord compatibility middleware of libburn.'''
|
|
|
|
Its paragon, cdrecord, is a powerful GPL'ed burn program included in Joerg
|
|
Schilling's cdrtools. cdrskin strives to be a second source for the services
|
|
traditionally provided by cdrecord. Currently it does CD-R and CD-RW this way.
|
|
Overwriteable media DVD-RAM, DVD+RW, DVD-RW, and BD-RE are handled differently
|
|
than with cdrecord-ProDVD in order to offer TAO-like single track recording.
|
|
Sequential DVD-R[W], DVD+R, DVD+R DL, BD-R are handled like CD-R[W] with TAO
|
|
and multi-session. Additionally cdrskin offers cdrecord-ProDVD-like mode DAO
|
|
with DVD-R[W].
|
|
|
|
cdrskin does not contain any bytes copied from cdrecord's sources.
|
|
Many bytes have been copied from the message output of cdrecord
|
|
runs, though. The most comprehensive technical overview of cdrskin
|
|
can be found in [http://libburnia-project.org/browser/libburn/trunk/cdrskin/README?format=txt cdrskin/README].
|
|
|
|
About libburn API for burning CD, DVD, and BD: http://api.libburnia-project.org
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
For yet unsupported media types see the advice to use dvd+rw-tools at
|
|
the end of this text.
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
About the command line options of cdrskin:
|
|
|
|
They are described in detail in [http://scdbackup.sourceforge.net/man_1_cdrskin_devel.html#OPTIONS section OPTIONS] of
|
|
[http://scdbackup.sourceforge.net/man_1_cdrskin_devel.html man cdrskin]
|
|
|
|
There are two families of options: cdrecord-compatible ones and options
|
|
which are specific to cdrskin. The latter are mostly used to configure
|
|
cdrskin for its task to emulate cdrecord. There are some, nevertheless,
|
|
which provide rather exotic unique features of cdrskin.
|
|
|
|
The cdrecord-compatible options are listed in the output of
|
|
{{{
|
|
cdrskin -help
|
|
}}}
|
|
where the option "help" has *one* dash. Online: [http://scdbackup.sourceforge.net/cdrskin_help_devel cdrskin -help]
|
|
|
|
For these options you may expect program behavior that is roughly the
|
|
same as described in original man cdrecord .
|
|
|
|
Online: http://cdrecord.berlios.de/old/private/man/cdrecord-2.0.html
|
|
|
|
The cdrskin-specific options are listed by
|
|
{{{
|
|
cdrskin --help
|
|
}}}
|
|
where the option "help" has *two* dashes. Online: [http://scdbackup.sourceforge.net/cdrskin__help_devel cdrskin --help]
|
|
|
|
Some are very experimental and should only be
|
|
used in coordination with the libburnia developer team.
|
|
Some are of general user interest, though:
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
--devices allows the sysadmin to scan the system for possible drives
|
|
and displays their detected properties.
|
|
The drives are listed one per line, with fields:
|
|
libburn-drive-number, sysadmin-device-file, permissions, vendor, type
|
|
{{{
|
|
0 dev='/dev/sr0' rwrw-- : 'HL-DT-ST' 'DVDRAM GSA-4082B'
|
|
}}}
|
|
This feature is valuable since cdrskin -scanbus will not give you
|
|
the device file name and its current permissions.
|
|
cdrskin will accept of course the proposed dev= option as address
|
|
for any usage of the drive.
|
|
|
|
Different from cdrecord, cdrskin is intended to be run without special
|
|
privileges, i.e. no superuser setuid. It is intended that the sysadmin
|
|
controls drive accessability by rw-permissions of the drive rather than
|
|
by x-permission of the burn binary. To be usable with cdrskin, the drive
|
|
has to offer both, r- and w-permission.
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
blank=as_needed applies the suitable blanking or formatting to make
|
|
any supported type of media ready for writing from scratch.
|
|
If this is not possible, e.g. because the media is written and not
|
|
re-usable, then the program run fails.
|
|
|
|
Option blank= offers several specialized blanking and formatting types,
|
|
which one may use for particular purposes on DVD-RW, DVD-RAM and BD-RE.
|
|
(See also below: blank=format_overwrite)
|
|
The drive offers a list of possible formats by cdrskin option --list_formats.
|
|
One should aquire MMC background information before making use of them.
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
cdrskin does not only read from and write to optical drives which comply
|
|
to the MMC standard but also does the same with regular files or block
|
|
devices other than optical drives.
|
|
|
|
Because the power to alter a disk file might be a bad surprise for a
|
|
traditional user of cdrecord, it is necessary to give option
|
|
--allow_emulated_drives before an emulated drive may be addressed.
|
|
Eventually one of the startup files would be a good place for it.
|
|
See man page, section FILES.
|
|
|
|
The addresses of emulated drives begin with the prefix "stdio:".
|
|
{{{
|
|
dev=stdio:/tmp/pseudo_drive
|
|
dev=stdio:/dev/usbstick
|
|
}}}
|
|
|
|
Regular files and block devices behave much like DVD-RAM.
|
|
|
|
Other file types may be valid targets for write-only operations.
|
|
This includes standard output, named pipes, character devices
|
|
{{{
|
|
dev=stdio:/dev/fd/1
|
|
dev=stdio:/tmp/named_pipe
|
|
dev=stdio:/dev/ptyxy
|
|
}}}
|
|
|
|
These files behave much like blank DVD-R.
|
|
|
|
All files used as pseudo-drives have to offer rw-permission.
|
|
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
The DVD capabilities of cdrskin differ from those of cdrecord-ProDVD. cdrskin
|
|
offers TAO-like multi-session with DVD-R[W], DVD+R[ DL] and TAO-like single
|
|
session with overwriteable DVD media. It also offers DAO on DVD-R[W] which is
|
|
probably the same as the traditional cdrecord-ProDVD write mode.
|
|
|
|
Non-cdrecord blank mode blank=format_overwrite brings a DVD-RW
|
|
disc from its initial profile "Sequential Recording" into profile state
|
|
"Restricted Overwrite".
|
|
{{{
|
|
cdrskin dev=/dev/sr0 -v blank=format_overwrite
|
|
}}}
|
|
|
|
DVD-RAM, DVD+RW, BD-RE and overwriteable DVD-RW appear to cdrskin as blank
|
|
media which are capable of taking only a single track. This track may be
|
|
positioned on a 32KiB aligned address, though.
|
|
{{{
|
|
cdrskin ... write_start_address=2412m ...
|
|
}}}
|
|
|
|
Non-cdrecord blank mode blank=deformat_sequential brings an overwriteable
|
|
DVD-RW back into state "Sequential Recording" with the capability of doing
|
|
multi-session, if the drive is capable of "Incremental Streaming"
|
|
(MMC feature 21h).
|
|
|
|
Used sequential DVD-RW media may be blanked by blank=fast or blank=all which
|
|
normally both do full blanking. Thus sequential DVD-RW behave much like large
|
|
CD-RW with possibly more than 99 tracks.
|
|
|
|
blank=deformat_sequential does minimal blanking of DVD-RW which usually yields
|
|
media incapable of "Incremental Streaming".
|
|
|
|
Option --prodvd_cli_compatible activates blank=fast and blank=all for
|
|
overwriteable DVD-RW which normally ignore those two options. It also makes
|
|
option -multi tolerable with media and write modes which are not suitable for
|
|
multi-session. (The default behavior of cdrskin deems me to be preferrable.)
|
|
|
|
Option --grow_overwriteable_iso gives cdrskin ISO pseudo-multi-session
|
|
capabilities on DVD-RAM, DVD+RW, BD-RE similar to growisofs.
|
|
Associated options blank=, -multi, -msinfo and -toc are available in this case.
|
|
They either pretend a blank media (if there is no ISO 9660 image) or appendable
|
|
media with a single session and track on it. blank= invalidates ISO images.
|
|
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
assert_write_lba=<lba> allows to ensure that the start block address which
|
|
was used with the formatter program (e.g. mkisofs -C) matches the start block
|
|
address which will be used by the upcoming burn.
|
|
|
|
E.g. cdrskin aborts with an error message if
|
|
{{{
|
|
assert_write_lba=0
|
|
}}}
|
|
is given but an appendable media is to be burned which would start at
|
|
block 68432.
|
|
|
|
|
|
An ISO-9660 file system image must be prepared according to a particular
|
|
block address on media. If the prepared address and the real address on media
|
|
do not match then the filesystem will not be mountable or may even cause system
|
|
trouble.
|
|
|
|
A sequential archive format like afio or star will not necessarily need such
|
|
a coordination of addresses. It might nevertheless be confusing to a reader
|
|
if the archive does not start at block 0.
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
fifo_start_at=<num> is a throughput enhancer for unsteady data streams
|
|
like they are produced by a compressing archiver program when piping to
|
|
CD on-the-fly. It makes better use of the general property of a FIFO
|
|
buffer to transport surplus bandwidth into the future. Yep. A time machine.
|
|
One-way, i fear.
|
|
|
|
FIFO originally was introduced by cdrecord's author Joerg Schilling in order
|
|
to protect mediocre burner hardware from suffering buffer underruns
|
|
and thus producing misburns (at 1x speed on CD-R media at the price of a
|
|
DVD-RAM nowadays). This purpose would not justify a fifo any more -
|
|
given the limited life time of burners and the seamless underrun protection
|
|
of contemporary consumer drives.
|
|
|
|
With an unsteady data stream the task of the buffer is to soak up peak
|
|
performance and to release it steadily at the drive's maximum speed.
|
|
The larger the buffer the more reserves can be built up and the longer
|
|
input drought can be compensated.
|
|
|
|
Original cdrecord has the historical property, though, to first wait until
|
|
the buffer is completely filled. Best practice for fighting drive
|
|
underruns, of course.
|
|
With a very fat fs=# buffer (128 MB for 12x CD is not unrealistic) this
|
|
can cause a big delay until burning finally starts and takes its due time.
|
|
|
|
fifo_start_at=<num> makes cdrskin start burning after the given number of bytes
|
|
is read rather than waiting for the FIFO to be completely full resp. the data
|
|
stream to end. It risks a few drive buffer underruns at the beginning of burn
|
|
- but modern drives stand this.
|
|
|
|
Usage examples:
|
|
{{{
|
|
cdrskin ... fs=128m fifo_start_at=20m ...
|
|
cdrskin ... fifo_start_at=0 ...
|
|
}}}
|
|
|
|
Note: no FIFO can give you better average throughput than the average
|
|
throughput of the data source and the throughput of the burner.
|
|
It can be used, though, to bring the effective throughput very close
|
|
to the theoretical limit. Especially with high speed media.
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
--no_rc allows you to surely ban influence from systemwide or user specific
|
|
default settings of cdrskin. Possible locations for such settings:
|
|
|
|
/etc/default/cdrskin
|
|
|
|
/etc/opt/cdrskin/rc
|
|
|
|
/etc/cdrskin/cdrskin.conf
|
|
|
|
$HOME/.cdrskinrc
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
dev_translation=<sep><from><sep><to> may be needed to foist cdrskin to
|
|
frontend programs of cdrecord which do *not* ask cdrecord -scanbus but
|
|
which make own assumptions and guesses about cdrecord's device addresses.
|
|
|
|
Normally, cdrskin understands all addresses which are suitable for cdrecord
|
|
under Linux. See cdrskin/README, "Pseudo-SCSI Adresses".
|
|
This option is mainly for (yet unknown) exotic configurations or very
|
|
stubborn frontend programs.
|
|
|
|
If a frontend refuses to work with cdrskin, look into the error protocol
|
|
of that frontend, look at the output of a run of cdrskin --devices and give
|
|
cdrskin the necessary hint.
|
|
Example: Your frontend insists in using "0,0,0" and --devices reported
|
|
dev='/dev/hdc' resp. cdrskin dev=ATA -scanbus reported "1,0,0" then this
|
|
would be the appropriate translation:
|
|
{{{
|
|
dev_translation=+0,0,0+/dev/hdc
|
|
}}}
|
|
The "+" character is a separator to be choosen by you.
|
|
Currently i am not aware of the need to choose any other than "+"
|
|
unless you get playful with custom translations like
|
|
{{{
|
|
dev_translation=-"cd+dvd"-1,0,0
|
|
}}}
|
|
See http://scdbackup.sourceforge.net/k3b_on_cdrskin.html
|
|
for an illustrated example with K3b 0.10 .
|
|
|
|
--------------------------------------------------------------------------
|
|
|
|
Advanced multi-session use cases as of dvd+rw-tools:
|
|
|
|
A special feature of dvd+rw-tools is growing of ISO-9660 filesystems on
|
|
overwriteable media. This is not the same as multi-session writing of cdrskin
|
|
with CD media, but retrieves additional information from the existing ISO
|
|
image and finally manipulates the start sectors of this existing image.
|
|
|
|
So, inspired by growisofs, cdrskin can offer DVD multi-session not only with
|
|
sequential DVD-R[W] and with DVD+R [DL], but also with DVD-RAM, DVD+RW, BD-RE
|
|
and even regular disk files or block devices other than CD/DVD writers.
|
|
This is enabled by option --grow_overwriteable_iso.
|
|
|
|
The libburnia project provides an integrated ISO-9660 multi-session tool
|
|
named [wiki:Xorriso xorriso] which tries to go one step beyond
|
|
growisofs. It uses [wiki:Libburn libburn] , [wiki:Libisofs libisofs]
|
|
and [wiki:Libisoburn libisoburn].
|
|
|
|
See [http://scdbackup.sourceforge.net/man_1_xorriso.html man xorriso].
|
|
|
|
--------------------------------------------------------------------------
|
|
|