lavf: add avformat_close_input().

It sets the supplied AVFormatContext pointer to NULL after freeing it,
which is safer and its name is consistent with other lavf functions.

Also deprecate av_close_input_file().

doc/APIchanges

@@ -13,6 +13,10 @@ libavutil:   2011-04-18
 
 API changes, most recent first:
 
+2011-xx-xx - xxxxxxx - lavf 53.17.0
+  Add avformat_open_input().
+  Deprecate av_close_input_file() and av_close_input_stream().
+
 2011-xx-xx - xxxxxxx - lavc 53.25.0
   Add nb_samples and extended_data fields to AVFrame.
   Deprecate AVCODEC_MAX_AUDIO_FRAME_SIZE.

libavformat/avformat.h

@@ -1570,12 +1570,22 @@ attribute_deprecated
 void av_close_input_stream(AVFormatContext *s);
 #endif
 
+#if FF_API_CLOSE_INPUT_FILE
 /**
+ * @deprecated use avformat_close_input()
  * Close a media file (but not its codecs).
  *
  * @param s media file handle
  */
+attribute_deprecated
 void av_close_input_file(AVFormatContext *s);
+#endif
+
+/**
+ * Close an opened input AVFormatContext. Free it and all its contents
+ * and set *s to NULL.
+ */
+void avformat_close_input(AVFormatContext **s);
 /**
  * @}
  */

libavformat/utils.c

@@ -2684,14 +2684,23 @@ void avformat_free_context(AVFormatContext *s)
     av_free(s);
 }
 
+#if FF_API_CLOSE_INPUT_FILE
 void av_close_input_file(AVFormatContext *s)
 {
+    avformat_close_input(&s);
+}
+#endif
+
+void avformat_close_input(AVFormatContext **ps)
+{
+    AVFormatContext *s = *ps;
     AVIOContext *pb = (s->iformat->flags & AVFMT_NOFILE) || (s->flags & AVFMT_FLAG_CUSTOM_IO) ?
                        NULL : s->pb;
     flush_packet_queue(s);
     if (s->iformat->read_close)
         s->iformat->read_close(s);
     avformat_free_context(s);
+    *ps = NULL;
     if (pb)
         avio_close(pb);
 }

libavformat/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFORMAT_VERSION_MAJOR 53
-#define LIBAVFORMAT_VERSION_MINOR 16
+#define LIBAVFORMAT_VERSION_MINOR 17
 #define LIBAVFORMAT_VERSION_MICRO  0
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
@@ -122,5 +122,8 @@
 #ifndef FF_API_SET_PTS_INFO
 #define FF_API_SET_PTS_INFO            (LIBAVFORMAT_VERSION_MAJOR < 54)
 #endif
+#ifndef FF_API_CLOSE_INPUT_FILE
+#define FF_API_CLOSE_INPUT_FILE        (LIBAVFORMAT_VERSION_MAJOR < 54)
+#endif
 
 #endif /* AVFORMAT_VERSION_H */