legacy/trunk/cdrskin/README

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            libburn.pykix.org    scdbackup.sourceforge.net/cdrskin
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Installation instructions at about line 50. First the legal stuff:
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This all is under GPL. Wether it can become LGPL is currently very unclear.
(So for now see explanation and GPL reference at the end of this text)
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Libburn. By Derek Foreman <derek@signalmarketing.com> and
            Ben Jansens <xor@orodu.net>
Copyright (C) 2002-2006  Derek Foreman and Ben Jansens

Mario Danic <mario.danic@gmail.com>, Luke Biddell <luke.biddell@gmail.com>,
Anant Narayanan <anant@kix.in> , Thomas Schmitt <scdbackup@gmx.net>
Copyright (C) 2006 Mario Danic, Luke Biddell, Anant Narayanan, Thomas Schmitt

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My thanks to the above authors (except myself, of course) for making the
following possible.

cdrskin. By Thomas Schmitt <scdbackup@gmx.net>
Integrated sub project of libburn.pykix.org but also published via:
http://scdbackup.sourceforge.net/cdrskin_eng.html
http://scdbackup.sourceforge.net/cdrskin-0.1.5.tar.gz
Copyright (C) 2006 Thomas Schmitt

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On top of libburn there is implemented cdrskin 0.1.5, a limited cdrecord
compatibility wrapper which allows to use some libburn features from
the command line.
Interested users of cdrecord are invited to participate in the development
of cdrskin. Contact: scdbackup@gmx.net


Important :
This software is provided as is. There is no warranty implied and no
protection against possible damages. You use this on your own risk.
Don't blame me or other authors of libburn if anything goes wrong.

I used it on my own risk with :
SuSE 7.2, kernel 2.4.4,  ide-scsi emulation, LITE-ON LTR48125S CD burner
SuSE 9.0, kernel 2.4.21, ide-scsi emulation, LG GSA-4082B CD/DVD burner
RIP-14.4, kernel 2.6.14, no ide-scsi,        with both above burners

It fails to compile or run on SuSE 6.4 (kernel 2.2.14).
It does not find the IDE CD burner on SuSE 7.2 without ide-scsi.
Other people sucessfully tested cdrskin on several kernel 2.6 based x86 Linux
systems, including 64 bit systems. (Further reports are welcome.)


                   Compilation, First Glimpse, Installation

Obtain cdrskin-0.1.5.tar.gz , take it to a directory of your choice and do:

    tar xzf cdrskin-0.1.5.tar.gz
    cd cdrskin-0.1.5

Or obtain a libburn.pykix.org SVN snapshot,
go into the toplevel directory of the snapshot (e.g.  cd libburn_pykix ),
and execute the autotools script ./bootstrap . Use autools version >= 1.7 .

Within that toplevel directory of either cdrskin-0.1.5 or libburn then execute:

    ./configure
    make

(Note: there are next-level directories "libburn" and "cdrskin". Those
would be the wrong ones. Meant is the highest directory of tarball resp. 
SVN download. Among others containing files "AUTHORS", "configure", 
"Makefile.am", as well as directories "libburn" and "cdrskin".)

This will already produce a cdrskin binary. But it might be necessary to
install libburn in order to use this binary. Installation of libburn is
beyond the scope of cdrskin. For this, see included libburn docs.

In order to surely get a standalone binary, execute

    cdrskin/compile_cdrskin.sh

Help texts :
    cdrskin/cdrskin --help
    cdrskin/cdrskin -help

Install (eventually as superuser) cdrskin to a directory where it can be found:
    cp cdrskin/cdrskin /usr/bin

It is not necessary for the standalone cdrskin binary to have libburn
installed, since it incorporates the necessary libburn parts at compile time.
It will not collide with an installed version of libburn either.
But libpthread must be installed on the system and glibc has to match. (See
below for a way to create a statically linked binary.)

Up to now i discourage to install the emerging libraries and to use them
with other programs. Unless you need my patches, better use vanilla libburn
for that.


                                    Usage

The user of cdrskin needs rw-permission for the CD burner device.
A list of rw-accessible drives can be obtained by

    cdrskin --devices

CD devices which offer no rw-permission are invisible to normal users.
The superuser should be able to see any usable drive and then set the
permissions as needed. If this hangs then there is a drive with
unexpected problems (locked, busy, broken, whatever). You might have to
guess the address of your (non-broken) burner by other means, then.
On Linux 2.4 this would be some /dev/sgN and on 2.6. some /dev/hdX.

The output of  cdrskin --devices  might look like

    0  dev='/dev/sg0'  rwrwr- :  'TEAC'  'CD-ROM CD-532S'
    1  dev='/dev/sg1'  rwrw-- :  'LITE-ON'  'LTR-48125S'

So full and insecure enabling of both for everybody would look like

    chmod a+rw /dev/sg0 /dev/sg1

(The CD-ROM is in these examples only for demonstrating the presence of another
 SCSI device. This /dev/sg0 may be left as it is and stay invisible for normal
 users.)

I strongly discourage to run cdrskin with setuid root or via sudo !
It is not checked for the necessary degree of hacker safety.


                                Usage examples 

Get an overview of cdrecord style addresses of available devices
    cdrskin -scanbus 

Obtain some info about the drive
    cdrskin dev=1,1,0 -checkdrive 

Obtain some info about the drive and the inserted media
    cdrskin dev=1,1,0 -atip 

Thoroughly blank a CD-RW
    cdrskin -v dev=1,1,0 blank=all eject_device=/dev/cdrom -eject 

Blank CD-RW sufficiently for making it ready for overwrite
    cdrskin -v dev=1,1,0 blank=fast eject_device=/dev/cdrom -eject 

Burn image file  my_image.iso  to CD
    cdrskin -v dev=1,1,0 speed=12 fs=8m -sao driveropts=burnfree padsize=300k \
            eject_device=/dev/cdrom -eject  my_image.iso 

Burn a compressed afio archive to CD on-the-fly
    find . | afio -oZ - | cdrskin -v dev=1,1,0 fs=32m speed=8 -sao \
                                  driveropts=burnfree padsize=300k tsize=650m - 


           Usage example with  http://scdbackup.sourceforge.net

Address may be a cdrecord-style  "scsibus,target,lun"  as listed with
cdrskin -scanbus (but not as listed with cdrecord -scanbus) :

    export SCDBACKUP_SCSI_ADR="1,1,0"

or a device file address as listed by --devices with an accessible drive :

    export SCDBACKUP_SCSI_ADR="/dev/sg1"

Set usage of cdrskin with appropriate options rather than cdrecord :

    export SCDBACKUP_CDRECORD="cdrskin -v -v tao_to_sao_tsize=650m eject_device=/dev/cdrw"

Run a backup :

    scdbackup_home


                                Restrictions

The convenient burn mode TAO is not available with libburn yet.
Therefore it has to be defaulted to mode SAO which needs to know the track
size in advance. non-cdrecord option  tao_to_sao_tsize=650m  causes each CD
to get burned up to 650 MB regardless of the payload size.

Command eject does not work with /dev/sgX and there is no easy way to determine
a drive's device file address which is suitable for eject.
So this address has to be supplied by eject_device=... unless your drive is
/dev/sg0 which is guessed as eject_device=/dev/sr0 .

No audio features, no multi session ... Please report your wishes.


                           Inspiration and Standard

For the original meaning of cdrecord options see :
    man cdrecord 
    (http://cdrecord.berlios.de/old/private/man/cdrecord-2.0.html)
Do not bother Joerg Schilling with any cdrskin problems.
(Be cursed if you install cdrskin as "cdrecord" without clearly forwarding
 this "don't bother Joerg" demand.)   
cdrskin does not contain any bytes copied from cdrecord's sources. Many bytes
have been copied from the message output of cdrecord runs, though. I am
thankful to Joerg Schilling for every single one of them.

Actually i, Thomas Schmitt, am a devoted user of cdrecord via my project
scdbackup which still runs a bit better with cdrecord than with cdrskin. TAO.
I have the hope that Joerg feels more flattered than annoyed by cdrskin.


                             Pseudo-SCSI Adresses

cdrecord and cdrskin share only some syntax of addresses but not the meaning
of the components. A cdrecord-style address for cdrskin
  [[prefix:]scsibus,]target,lun
corresponds either to a device file address or to a libburn drive number.
Component "scsibus" indicates the translation method. Defined busses are:
  0  target is the libburn drivenumber as listed with --devices
  1  associated to device file /dev/sgN , target chooses N
  2  associated to device file /dev/hdX , target 0='a', 1='b' ..., 25='z' 

So "1,1,0" is /dev/sg1, "2,3,0" is /dev/hdd, "0,2,0" is libburn drive #2 at
some unspecified device file. 
This scheme shall help to keep cdrecord-style addresses stable and exchangeable
between users without excluding drives with unexpected device addresses.
The numbering on bus 0 is prone to arbitrary changes caused by changes in
drive accessability.
Further busses may emerge as libburn evolves. "prefix" and "lun" may get
a meaning. To stay upward compatible, use addresses as printed by -scanbus.

Some programs or users have their own ideas about the address of their burner.
K3b 0.10 for example derives cdrecord addresses by own examination of the
devices and not by calling cdrecord -scanbus.
To direct such callers to the appropriate drives, cdrskin allows to define
device address aliases. Like
  cdrskin dev_translation=+1,0,0+/dev/sg1 \
          dev_translation=+ATA:1,0,0+/dev/sg1 \
          dev_translation=-"cd+dvd"-1,1,0 \
          ...
Any of the addresses dev=1,0,0, dev=ATA:1,0,0, dev=cd+dvd will be mapped to
/dev/sg1 resp. to its standard alias 1,1,0.
The first character after "dev_translation=" defines the character which
separates the two parts of the translation pair. (Above: "+" and "-".)

In K3b 0.10 it is possible to employ alternative writer programs by setting
their full path (e.g. /usr/bin/cdrskin) in menu
  Settings:Configure K3b...:Programs:Search Path 
and to make them default in menu
  Settings:Configure K3b...:Programs:Programs:
A suitable setting for "cdrecord" in menu 
  Settings:Configure K3b...:Programs:User Parameters
would then probably be
  -v dev_translation=+1,0,0+/dev/sg1
You will learn from button "Show Debugging Output" after a failed burn run
what cdrecord command was used with what address "dev=...". This address "..."
will be the right one to replace "1,0,0" in above example.


                                 Startup Files

If not --no_rc is the first argument then cdrskin attempts on startup to read
arguments from the following three files:
  /etc/defaults/cdrskin
  /etc/opt/cdrskin/rc
  $HOME/.cdrskinrc
The files are read in the sequence given above.
Each readable line is treated as one single argument. No extra blanks,
no comments, no empty lines are permitted.

Example content of a startup file:
dev=1,1,0
dev_translation=+1,0,0+1,1,0
--fifo_start_empty
fs=16m


                        Special compilation variations

You may get a (super fat) statically linked binary by :
    cdrskin/compile_cdrskin.sh -static
if your system supports static linking, at all. This will not help with kernels
which do not properly support the necessary low-level interfaces chosen by
your compile-time libraries.

A size reduced but fully functional binary may be produced by 
    cdrskin/compile_cdrskin.sh -do_strip

An extra lean binary with reduced capabilities is created by
    cdrskin/compile_cdrskin.sh -do_diet -do_strip
It will not read startup files, will abort on option  dev_translation= ,
will not have a fifo buffer, and will not be able to put out help texts or
debugging messages.


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It is my understanding that you may put a binary of unchanged cdrskin on any
suitable system if you only tell the user that the source is available for
free in the internet. Search engines will find it. Better than any URL here.

If you link to the libraries or if you make changes in our source, you will 
currently have to release your own programs under GPL and nothing else, i fear.
As it looks no single one of us currently has the right to issue any other
license.
You may submit source changes which affect our standalone binaries and if
they get included you may distribute binaries derived from our new code base.

signed: Thomas Schmitt (and his understanding of GPL), author of this README.
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    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA