lavfi: add avfilter_unref_bufferp()

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

doc/APIchanges

@@ -13,6 +13,9 @@ libavutil:   2011-04-18
 
 API changes, most recent first:
 
+2012-04-20 - xxxxxxx - lavfi 2.70.100
+  Add avfilter_unref_bufferp() to avfilter.h.
+
 2012-04-12 - xxxxxxx - lavfi 2.68.100
   Install libavfilter/asrc_abuffer.h public header.
 

libavfilter/avfilter.c

@@ -160,6 +160,12 @@ void avfilter_unref_buffer(AVFilterBufferRef *ref)
     av_free(ref);
 }
 
+void avfilter_unref_bufferp(AVFilterBufferRef **ref)
+{
+    avfilter_unref_buffer(*ref);
+    *ref = NULL;
+}
+
 void avfilter_insert_pad(unsigned idx, unsigned *count, size_t padidx_off,
                          AVFilterPad **pads, AVFilterLink ***links,
                          AVFilterPad *newpad)

libavfilter/avfilter.h

@@ -187,6 +187,15 @@ AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
  */
 void avfilter_unref_buffer(AVFilterBufferRef *ref);
 
+/**
+ * Remove a reference to a buffer and set the pointer to NULL.
+ * If this is the last reference to the buffer, the buffer itself
+ * is also automatically freed.
+ *
+ * @param ref pointer to the buffer reference
+ */
+void avfilter_unref_bufferp(AVFilterBufferRef **ref);
+
 /**
  * A list of supported formats for one end of a filter link. This is used
  * during the format negotiation process to try to pick the best format to

libavfilter/version.h

@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  2
-#define LIBAVFILTER_VERSION_MINOR 70
+#define LIBAVFILTER_VERSION_MINOR 71
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \