New API call burn_write_opts_set_bdr_obs_exempt()

cdrskin/cdrskin_timestamp.h

@@ -1 +1 @@
-#define Cdrskin_timestamP "2021.09.02.181259"
+#define Cdrskin_timestamP "2021.09.12.084139"

libburn/libburn.h

@@ -3389,6 +3389,21 @@ void burn_write_opts_set_dvd_obs(struct burn_write_opts *opts, int obs);
 void burn_write_opts_set_obs_pad(struct burn_write_opts *opts, int pad);
 
 
+/* ts C10909 */
+/** Exempts BD-R media from the elsewise unavoidable automatic padding of the
+    last write chunk to its full size.
+    Even if this exempt is granted it gets into effect only if stream recording
+    is disabled and burn_write_opts_set_obs_pad() is set to 0.
+    @param opts The write opts to change
+    @param value  1= possibly exempt BD-R from end chunk padding.
+                  0= always act on BD-R as if
+                     burn_write_opts_set_obs_pad(opts, 1) is in effect.
+    @since 1.5.6
+*/
+void burn_write_opts_set_bdr_obs_exempt(struct burn_write_opts *opts,
+                                        int value);
+
+
 /* ts A91115 */
 /** Sets the rhythm by which stdio pseudo drives force their output data to
     be consumed by the receiving storage device. This forcing keeps the memory

libburn/libburn.ver

@@ -186,6 +186,7 @@ burn_write_opts_auto_write_type;
 burn_write_opts_free;
 burn_write_opts_get_drive;
 burn_write_opts_new;
+burn_write_opts_set_bdr_obs_exempt;
 burn_write_opts_set_dvd_obs;
 burn_write_opts_set_fail21h_sev;
 burn_write_opts_set_fillup;

libburn/options.c

@@ -55,6 +55,7 @@ struct burn_write_opts *burn_write_opts_new(struct burn_drive *drive)
 	opts->obs_pad = 0;
 #endif
 
+	opts->bdr_obs_exempt = 0;
 	opts->start_byte = -1;
 	opts->fill_up_media = 0;
 	opts->force_is_set = 0;
@@ -535,6 +536,14 @@ void burn_write_opts_set_obs_pad(struct burn_write_opts *opts, int pad)
 }
 
 
+/* ts C10909: API */
+void burn_write_opts_set_bdr_obs_exempt(struct burn_write_opts *opts,
+					int value)
+{
+	opts->bdr_obs_exempt = !!value;
+}
+
+
 /* ts A91115: API */
 void burn_write_opts_set_stdio_fsync(struct burn_write_opts *opts, int rhythm)
 {

libburn/options.h

@@ -46,6 +46,9 @@ struct burn_write_opts
 	                2 indicates burn_write_opts_set_obs_pad(,1)
 	             */
 
+	/* 1= do not apply obs_pad=1 to BD-R if not stream recording. */
+	int bdr_obs_exempt;
+
 	/* ts A61222 : Start address for media which offer a choice */
 	off_t start_byte;
 

libburn/write.c

@@ -1658,16 +1658,6 @@ int burn_disc_open_track_dvd_plus_r(struct burn_write_opts *o,
 				size += (off_t) (o->obs - (size % o->obs));
 		}
 
-		/* <<< Only for now until the first DVD+R succeeded */
-		if (!o->obs_pad) {
-			sprintf(msg, "Program error: encountered DVD+R without chunk padding");
-			libdax_msgs_submit(libdax_messenger, d->global_index,
-				0x00000004,
-				LIBDAX_MSGS_SEV_FATAL, LIBDAX_MSGS_PRIO_HIGH,
-				msg, 0, 0);
-			{ret = 0; goto ex;}
-		}
-
 		ret = d->reserve_track(d, size);
 		if (ret <= 0) {
 			sprintf(msg, "Cannot reserve track of %.f bytes",
@@ -2436,9 +2426,17 @@ int burn_dvd_write_sync(struct burn_write_opts *o,
 				msg, 0, 0);
 			goto early_failure;
 		}
-		/* ??? padding needed ??? cowardly doing it for now */
-		if (o->obs_pad < 2)
+		/* Unaligned BD-R track end works with various drives and
+		   produces exact READ CAPACITY results.
+		   Nevertheless stream recording hates unaligned WRITE.
+		   With DVD+R it seems that obs_pad is silently applied by the
+		   drive if a non-aligned final WRITE is received.
+		*/
+		if (o->obs_pad < 2 &&
+		    !(d->current_profile == 0x41 && !d->do_stream_recording &&
+		      o->bdr_obs_exempt))
 			o->obs_pad = 1; /* fill-up track's last obs buffer */
+
 		if (d->current_profile == 0x41) /* BD-R */
 			o->obs = Libburn_bd_r_obS;
 		if (d->do_stream_recording) {