libavformat: Add a function for freeing an AVFormatContext

This function is useful for freeing data structures allocated by
muxers, which currently have to be freed manually by the caller.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
(cherry picked from commit f124b087ee)

libavformat/avformat.h

@@ -1074,8 +1074,8 @@ attribute_deprecated AVFormatContext *av_alloc_format_context(void);
 
 /**
  * Allocate an AVFormatContext.
- * Can be freed with av_free() but do not forget to free everything you
- * explicitly allocated as well!
+ * avformat_free_context() can be used to free the context and everything
+ * allocated by the framework within it.
  */
 AVFormatContext *avformat_alloc_context(void);
 
@@ -1231,6 +1231,12 @@ void av_close_input_stream(AVFormatContext *s);
  */
 void av_close_input_file(AVFormatContext *s);
 
+/**
+ * Free an AVFormatContext and all its streams.
+ * @param s context to free
+ */
+void avformat_free_context(AVFormatContext *s);
+
 /**
  * Add a new stream to a media file.
  *

libavformat/utils.c

@@ -2556,12 +2556,17 @@ int av_read_pause(AVFormatContext *s)
 
 void av_close_input_stream(AVFormatContext *s)
 {
-    int i;
-    AVStream *st;
-
     flush_packet_queue(s);
     if (s->iformat->read_close)
         s->iformat->read_close(s);
+    avformat_free_context(s);
+}
+
+void avformat_free_context(AVFormatContext *s)
+{
+    int i;
+    AVStream *st;
+
     for(i=0;i<s->nb_streams;i++) {
         /* free all data in a stream component */
         st = s->streams[i];

libavformat/version.h

@@ -24,7 +24,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFORMAT_VERSION_MAJOR 52
-#define LIBAVFORMAT_VERSION_MINOR 95
+#define LIBAVFORMAT_VERSION_MINOR 96
 #define LIBAVFORMAT_VERSION_MICRO  0
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \