lavu: add helper functions for integer lists.

Add av_int_list_length() to compute a list length.
Add av_opt_set_int_list() to set a binary option.

Signed-off-by: Nicolas George <nicolas.george@normalesup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 21 insertions, 0 deletions

diff --git a/libavutil/avutil.h b/libavutil/avutil.h
index 78deff1fd8..d71eb1ef4c 100644
--- a/libavutil/avutil.h
+++ b/libavutil/avutil.h
@@ -253,6 +253,27 @@ static inline void *av_x_if_null(const void *p, const void *x)
 }
 
 /**
+ * Compute the length of an integer list.
+ *
+ * @param elsize  size in bytes of each list element (only 1, 2, 4 or 8)
+ * @param term    list terminator (usually 0 or -1)
+ * @param list    pointer to the list
+ * @return  length of the list, in elements, not counting the terminator
+ */
+unsigned av_int_list_length_for_size(unsigned elsize,
+                                     const void *list, uint64_t term);
+
+/**
+ * Compute the length of an integer list.
+ *
+ * @param term  list terminator (usually 0 or -1)
+ * @param list  pointer to the list
+ * @return  length of the list, in elements, not counting the terminator
+ */
+#define av_int_list_length(list, term) \
+    av_int_list_length_for_size(sizeof(*list), list, term)
+
+/**
  * @}
  * @}
  */