Compile time option for obs_pad

cdrskin/cdrskin.1

@@ -1484,8 +1484,10 @@ stdio: pseudo-drive up to the full size of an output chunk.
 This padding has to be applied automatically to the other DVD and BD media
 types, where it causes e.g. ISO images to have trailing unclaimed blocks.
 .br
-There are reports that DAO sessions of a size that is not a multiple of 16
-blocks abort on some Linux kernels and/or DVD drives.
+Use this option if there is the suspicion that DAO sessions abort with
+your kernel and/or DVD drive, if their size is not a multiple of 16 blocks.
+.br
+This option may also get enabled at compile time of libburn.
 .TP
 .BI \--old_pseudo_scsi_adr
 Linux specific:

cdrskin/cdrskin_timestamp.h

@@ -1 +1 @@
-#define Cdrskin_timestamP "2012.04.13.112832"
+#define Cdrskin_timestamP "2012.04.13.202654"

configure.ac

@@ -228,6 +228,19 @@ else
 fi
 CFLAGS="$LIBBURN_DVD_OBS_64K $CFLAGS"
 
+dnl ts B20413
+AC_ARG_ENABLE(dvd-obs-pad,
+[  --enable-dvd-obs-pad    pad DVD DAO sessions to 32 resp. 64 KB, default=no],
+               , enable_dvd_obs_pad=no)
+if test x$enable_dvd_obs_pad = xyes; then
+    LIBBURN_DVD_OBS_PAD="-DLibburn_dvd_always_obs_paD"
+    echo "enabled  padding of DVD DAO sessions to 32 resp. 64 KB"
+else
+    LIBBURN_DVD_OBS_64K=
+    echo "disabled padding of DVD DAO sessions to 32 resp. 64 KB"
+fi
+CFLAGS="$LIBBURN_DVD_OBS_PAD $CFLAGS"
+
 dnl ts A91218
 AC_ARG_ENABLE(libcdio,
 [  --enable-libcdio        Enable EXPERIMENTAL use of libcdio as system adapter, default=no],

libburn/libburn.h

@@ -3083,6 +3083,8 @@ void burn_write_opts_set_dvd_obs(struct burn_write_opts *opts, int obs);
 /* ts B20406 */
 /** Overrides the automatic decision whether to pad up the last write chunk to
     its full size. This applies to DVD, BD and stdio: pseudo-drives.
+    Note: This override may get enabled fixely already at compile time by
+          defining macro  Libburn_dvd_always_obs_paD .
     @param opts The write opts to change
     @param pad  1 means to pad up in any case, 0 means automatic decision.
     @since 1.2.4

libburn/options.c

@@ -46,7 +46,13 @@ struct burn_write_opts *burn_write_opts_new(struct burn_drive *drive)
 	opts->underrun_proof = drive->mdata->underrun_proof;
 	opts->perform_opc = 1;
 	opts->obs = -1;
+
+#ifdef Libburn_dvd_always_obs_paD
+	opts->obs_pad = 1;
+#else
 	opts->obs_pad = 0;
+#endif
+
 	opts->start_byte = -1;
 	opts->fill_up_media = 0;
 	opts->force_is_set = 0;