Re: growisofs won't write double layer DVDs

[Andy Polyakov <appro@fy.chalmers.se>]

> > > > I recommend you to use cdrecord instead of growisofs. 
> > > > Cdrecord will tell the drive to do laser power calibration
> > > >       
> > > cdrecord does not do that to DVD+ media.
> > >     
> >
> > Wrong: cdrecord of course does a power calibration for DVD+
> >   
>
> I thought it bypassed that for DVD+,

It is.

> I saw it in the code and can't find 
> it again. It looked as if a text which fails on DVD+ went around that logic.
> Does cdr_opc get set somewhere I'm missing? That could explain why some 
> media I have don't work well with one burner and cdrecord.

It should be noted that explicit *host-initiated* OPC procedure is *not* 
defined for single-layer DVD+ media. Meaning that if you refer to single 
layer media, then there hardly is cure (at least not in pure MMC terms). 
As it turns out it, host-initiated OPC, is defined for double layer 
though and it might make difference...

Christian [and Bill], if you have energy and media to spare, could you 
test following:

- download dvd+rw-tools source and unpack;
- copy attached opc.cpp to dvd+rw-tools source catalog;
- change directory to dvd+rw-tools source catalog;
- compile it with 'g++ opc.cpp -o opc';
- load media;
- execute './opc /dev/dvd';
- then *without reloading the media* attempt growisofs recording;

It might be interesting to have a look at verbose dvd+rw-mediainfo 
output before and after opc. In other words also execute dvd+rw-medianfo 
/dev/dvd -v before and after opc (all *without reloading the media*), 
compare them and send them [*if* they are different]. A.


#include "transport.hxx"

int main(int argc,char *argv[])
{ Scsi_Command cmd;
  int err;

    if (!cmd.associate(argv[1])) perror("can't open"),exit(1);

    cmd[0]=0x54;
    cmd[1]=0x1;
    cmd[9]=0;

    if (err=cmd.transport()) sperror("SEND OPC INFORMATION",err);

    wait_for_unit (cmd,NULL);
}