filter_brightness.c: fix the wonkiness by filtering chroma as well.

git-svn-id: https://mlt.svn.sourceforge.net/svnroot/mlt/trunk/mlt@1353 d19143bc-622f-0410-bfdd-b5b2a6649095

diff --git a/src/modules/core/filter_brightness.c b/src/modules/core/filter_brightness.c
index d597e8ab1df4113ef2c240ac3ac8169b84e48365..07dce1c8160cdeef12d00a9cf194dc58c2187f31 100644 (file)
--- a/src/modules/core/filter_brightness.c
+++ b/src/modules/core/filter_brightness.c
@@ -25,6 +25,8 @@
 #include <stdlib.h>
 #include <math.h>
 
+#define CLAMP( x, min, max ) (x) < (min) ? (min) : (x) > (max) ? (max) : (x)
+
 /** Do it :-).
 */
 
@@ -42,15 +44,15 @@ static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *
                // Only process if level is something other than 1
                if ( level != 1.0 )
                {
+                       int i = *width * *height + 1;
                        uint8_t *p = *image;
-                       uint8_t *q = *image + *width * *height * 2;
-                       int32_t x = 0;
                        int32_t m = level * ( 1 << 16 );
+                       int32_t n = 128 * ( ( 1 << 16 ) - m );
 
-                       while ( p != q )
+                       while ( --i )
                        {
-                               x = ( *p * m ) >> 16;
-                               *p = x < 16 ? 16 : x > 235 ? 235 : x;
+                               p[0] = CLAMP( (p[0] * m) >> 16, 16, 235 );
+                               p[1] = CLAMP( (p[1] * m + n) >> 16, 16, 240 );
                                p += 2;
                        }
                }
@@ -66,7 +68,7 @@ static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 {
        // Get the starting brightness level
        double level = fabs( mlt_properties_get_double( MLT_FILTER_PROPERTIES( this ), "start" ) );
-       
+
        // If there is an end adjust gain to the range
        if ( mlt_properties_get( MLT_FILTER_PROPERTIES( this ), "end" ) != NULL )
        {