-------------------------------------------------------------------------- cdrskin Wiki - plain text copy -------------------------------------------------------------------------- [[Image(source:/libburn/trunk/cdrskin/doener_150x200_tr.gif)]] [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 and DVD-RW are handled differently than with cdrecord-ProDVD in order to offer TAO-like single track recording. 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.pykix.org/browser/libburn/trunk/cdrskin/README?format=txt cdrskin/README]. About libburn API for burning CD: http://libburnia-api.pykix.org -------------------------------------------------------------------------- Appending sessions to an unclosed CD is restricted to write mode TAO. (Users who have a burner which succeeds with a follow-up session via cdrecord -sao : please contact us.) For DVD types other than DVD-RAM, DVD+RW, DVD-RW and for appending sessions to ISO filesystems on DVD see the advise 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/sg0' 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. -------------------------------------------------------------------------- Non-cdrecord blank mode blank=format_overwrite is needed to bring a DVD-RW disc from its initial profile "Sequential Recording" into profile state "Restricted Overwrite". The latter is usable with cdrskin. {{{ cdrskin dev=/dev/sr0 -v blank=format_overwrite }}} DVD-RAM, DVD+RW 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 ... }}} -------------------------------------------------------------------------- fifo_start_at= 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= 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= 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 . -------------------------------------------------------------------------- DVD advise: For burning of DVD media other than DVD-RAM, DVD+RW, DVD-RW, the cdrskin project currently advises to use Andy Polyakov's dvd+rw-tools which despite their historic name burn for me on above burner: DVD-RAM, DVD+RW, DVD+R, DVD-RW, DVD-R and are also capable of dual layer and even BD discs. http://fy.chalmers.se/~appro/linux/DVD+RW/tools They are not compatible or related to cdrecord resp. cdrecord-ProDVD (now obsoleted by original source cdrtools cdrecord with identical capabilities besides the license key). 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 for growable ISO filesystems on DVD-RAM or DVD+RW growisofs is the only choice, currently. --------------------------------------------------------------------------