Re: Wodim: How to read from stdin?
Til Schubbe <lists@lists.schubbe.org> wrote:
> Hi,
>
> on 25 May 2007 Thomas Schmitt wrote:
>
> | I.e. this does not work:
> | $ cat /dvdbuffer/fertig.iso | wodim -v dev=0,0,0 -
> | ...
> | wodim: Track 1 has unknown length.
>
> I'm getting the same errormessage. How can wodim read from stdin?
First a question: Why do you like to use defective and illegal software
like wodim?
Wodim is a dead fork created by a hostile downstream paketzier from a very
outdated version of cdrecord. Wodim has many bugs that never have been in
cdrecord and wodim cannot be legally distributed as it is in conflict with
the GPL and with the Copyright law.
There are currently more than 100 well known bugs in the bug tracking systems
of the various Linux distibutors that decided to go the illegal way and since
May 6th 2007, bug reports for wodim are ignored and even easy to fix bugs stay
around since then.
I cannot speak for your DVD problem as in wodim, the mature and now 12 year old
original DVD support from cdrecord was ripped off and replaced by some half
baken code that fails in many cases and does e.g. not support dual layer media
at all.
I can however tell you why the original software (cdrecord) will behave the same
way in your case:
In the early years of CD recording, CD writers did only support to write in TAO
mode and for this reason, old versions of cdrecord did by default write in TAO
mode. In TAO mode, it is possible to write tracks of unknown length as the
writer writes the TOC _after_ the data and after interrupting the write
process..... As the forward error correction used on CDs is computing a result
that includes parts of the previous sector, a CD written in TAO mode has
unreadable sectors and gives audible clicks (if it is used for audio data).
There was a mode better than TAO in these days (RAW mode) but this mode requires
to have a working Reed Solomon forward error correction encoding implementation.
Such an implementation was made by Heiko Eißfeld in 1998 - 1999 for the cdrtools
project and BTW: all current OSS implementations of the RS encoder either use
the software from Heiko or software that was derived from Heikos work.
In September 1997, the first DVD writer was made by Pioneer and this DVD
recorder did _only_ support to write in SAO mode (in SAO mode, the creation of
the forward error correction code is done in the drive). I received one of the
very early samples of the Pioneer DVD writer in January 1998 and finished the
first DVD writing support (in SAO mode) for cdrecord in February 1998.
A short time later, SAO mode and RAW mode writing for CDs was added to cdrecord.
As in these modes, writing is uninterrupted and the TOC is written first, the
size of the tracks needs to be known in advance but the quality of the resulting
media is better than when written in TAO mode.
Since a while, cdrecord defaults to write in SAO mode because this creates
better results than when writing in TAO mode. If you like to write from a pipe,
you need to tell cdrecord about the size of the tracks. There is of course an
example in the EXAMPLES section of the cdrecord man page, see cdrecord man page.
Please note that software that allows to write media without knowing the size
in advance is not writing in SAO mode.
Jörg
--
EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
js@cs.tu-berlin.de (uni)
joerg.schilling@fokus.fraunhofer.de (work) Blog: http://schily.blogspot.com/
URL: http://cdrecord.berlios.de/private/ ftp://ftp.berlios.de/pub/schily
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