Re: growisofs won't write double layer DVDs

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

> > > 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+

LOCAL BOOL
do_opc(scgp, dp, flags)
        SCSI    *scgp;
        cdr_t   *dp;
        UInt32_t flags;
{
        if ((flags & F_DUMMY) == 0 && dp->cdr_opc) {
                if (debug || lverbose) {
                        printf("Performing OPC...\n");
                        flush();
                }
                if (dp->cdr_opc(scgp, NULL, 0, TRUE) < 0) {
                        errmsgno(EX_BAD, "OPC failed.\n");
                        if ((flags & F_FORCE) == 0)
                                return (FALSE);
                }
        }
        return (TRUE);
}

So it's up to [non-NULL!] dp->cdr_opc. And what's dp->cdr_opc for DVD+ 
media?

grep OPC drv_dvdplus.c
        (int(*)__PR((SCSI *, caddr_t, int, int)))NULL,  /* no OPC */
        (int(*)__PR((SCSI *, caddr_t, int, int)))NULL,  /* no OPC */
        (int(*)__PR((SCSI *, caddr_t, int, int)))NULL,  /* no OPC */

A.