ass: add ass_set_check_readorder() API function

Not all API users will keep the event list on seeking. This also gives
the opportunity to API users to handle severely broken files with
duplicate ReadOrder entries. (It is not known whether this is really
needed, however VSFilter does not deduplicate using the ReadOrder
field.)

1 files changed, 11 insertions, 1 deletions

diff --git a/libass/ass.h b/libass/ass.h
index c2802f7..bafbe8a 100644
--- a/libass/ass.h
+++ b/libass/ass.h
@@ -24,7 +24,7 @@
 #include <stdarg.h>
 #include "ass_types.h"
 
-#define LIBASS_VERSION 0x01301000
+#define LIBASS_VERSION 0x01302000
 
 #ifdef __cplusplus
 extern "C" {
@@ -577,6 +577,16 @@ void ass_process_chunk(ASS_Track *track, char *data, int size,
                        long long timecode, long long duration);
 
 /**
+ * \brief Set whether the ReadOrder field when processing a packet with
+ * ass_process_chunk() should be used for eliminating duplicates.
+ * \param check_readorder 0 means do not try to eliminate duplicates; 1 means
+ * use the ReadOrder field embedded in the packet as unique identifier, and
+ * discard the packet if there was already a packet with the same ReadOrder.
+ * Other values are undefined.
+ */
+void ass_set_check_readorder(ASS_Track *track, int check_readorder);
+
+/**
  * \brief Flush buffered events.
  * \param track track
 */