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, 19 insertions, 0 deletions

diff --git a/libavutil/utils.c b/libavutil/utils.c
index fbfbc49e1c..291c736454 100644
--- a/libavutil/utils.c
+++ b/libavutil/utils.c
@@ -79,3 +79,22 @@ char av_get_picture_type_char(enum AVPictureType pict_type)
     default:                 return '?';
     }
 }
+
+unsigned av_int_list_length_for_size(unsigned elsize,
+                                     const void *list, uint64_t term)
+{
+    unsigned i;
+
+    if (!list)
+        return 0;
+#define LIST_LENGTH(type) \
+    { type t = term, *l = list; for (i = 0; l[i] != t; i++); }
+    switch (elsize) {
+    case 1: LIST_LENGTH(uint8_t);  break;
+    case 2: LIST_LENGTH(uint16_t); break;
+    case 4: LIST_LENGTH(uint32_t); break;
+    case 8: LIST_LENGTH(uint64_t); break;
+    default: av_assert0(!"valid element size");
+    }
+    return i;
+}