Add inline function for signed linear subtraction.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@81326 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/include/asterisk/utils.h b/include/asterisk/utils.h
index 6f97770..d87ea03 100644 (file)
--- a/include/asterisk/utils.h
+++ b/include/asterisk/utils.h
@@ -283,6 +283,19 @@ static force_inline void ast_slinear_saturated_add(short *input, short *value)
        else
                *input = (short) res;
 }
+
+static force_inline void ast_slinear_saturated_subtract(short *input, short *value)
+{
+       int res;
+
+       res = (int) *input - *value;
+       if (res > 32767)
+               *input = 32767;
+       else if (res < -32767)
+               *input = -32767;
+       else
+               *input = (short) res;
+}
        
 static force_inline void ast_slinear_saturated_multiply(short *input, short *value)
 {