Add av_clip_uintp2() function

Signed-off-by: Mans Rullgard <mans@mansr.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/libavutil/common.h b/libavutil/common.h
index e5c1dfdff5..a985fa4804 100644
--- a/libavutil/common.h
+++ b/libavutil/common.h
@@ -170,6 +170,18 @@ static av_always_inline av_const int32_t av_clipl_int32_c(int64_t a)
 }
 
 /**
+ * Clip a signed integer to an unsigned power of two range.
+ * @param  a value to clip
+ * @param  p bit position to clip at
+ * @return clipped value
+ */
+static av_always_inline av_const unsigned av_clip_uintp2_c(int a, int p)
+{
+    if (a & ~((1<<p) - 1)) return -a >> 31 & ((1<<p) - 1);
+    else                   return  a;
+}
+
+/**
  * Clip a float value into the amin-amax range.
  * @param a value to clip
  * @param amin minimum value of the clip range
@@ -362,6 +374,9 @@ static av_always_inline av_const int av_popcount_c(uint32_t x)
 #ifndef av_clipl_int32
 #   define av_clipl_int32   av_clipl_int32_c
 #endif
+#ifndef av_clip_uintp2
+#   define av_clip_uintp2   av_clip_uintp2_c
+#endif
 #ifndef av_clipf
 #   define av_clipf         av_clipf_c
 #endif