lavu/fifo: add av_fifo_freep function

Function allows to free fifo and reset freed pointer.
Signed-off-by: Lukasz Marek <lukasz.m.luki2@gmail.com>

doc/APIchanges

@@ -15,6 +15,9 @@ libavutil:     2012-10-22
 
 API changes, most recent first:
 
+2014-05-xx - xxxxxxx - lavu 52.82.0 - fifo.h
+  Add av_fifo_freep() function.
+
 2014-05-02 - ba52fb11 - lavu 52.81.0 - opt.h
   Add av_opt_set_dict2() function.
 

libavutil/fifo.c

@@ -45,6 +45,14 @@ void av_fifo_free(AVFifoBuffer *f)
     }
 }
 
+void av_fifo_freep(AVFifoBuffer **f)
+{
+    if (f) {
+        av_fifo_free(*f);
+        *f = NULL;
+    }
+}
+
 void av_fifo_reset(AVFifoBuffer *f)
 {
     f->wptr = f->rptr = f->buffer;

libavutil/fifo.h

@@ -47,6 +47,12 @@ AVFifoBuffer *av_fifo_alloc(unsigned int size);
  */
 void av_fifo_free(AVFifoBuffer *f);
 
+/**
+ * Free an AVFifoBuffer and reset pointer to NULL.
+ * @param f AVFifoBuffer to free
+ */
+void av_fifo_freep(AVFifoBuffer **f);
+
 /**
  * Reset the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied.
  * @param f AVFifoBuffer to reset

libavutil/version.h

@@ -56,7 +56,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  52
-#define LIBAVUTIL_VERSION_MINOR  81
+#define LIBAVUTIL_VERSION_MINOR  82
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \