+ Correction to alpha mask generation

[mlt] / src / modules / core / transition_composite.c

diff --git a/src/modules/core/transition_composite.c b/src/modules/core/transition_composite.c
index 2bc482100c1e7e3565f38b4510e49920e30f0ba9..f4d8663a55e151d3472c3caeed035eb52d2ede2d 100644 (file)
--- a/src/modules/core/transition_composite.c
+++ b/src/modules/core/transition_composite.c
@@ -391,7 +391,7 @@ static void composite_line_yuv( uint8_t *dest, uint8_t *src, int width, uint8_t
                dest++;
                *dest = sample_mix( *dest, *src++, mix );
                dest++;
-               *alpha_a = mix | *alpha_a;
+               *alpha_a = ( mix >> 8 ) | *alpha_a;
                alpha_a ++;
        }
 }
@@ -408,7 +408,7 @@ static void composite_line_yuv_or( uint8_t *dest, uint8_t *src, int width, uint8
                dest++;
                *dest = sample_mix( *dest, *src++, mix );
                dest++;
-               *alpha_a ++ = mix;
+               *alpha_a ++ = mix >> 8;
        }
 }
 
@@ -424,7 +424,7 @@ static void composite_line_yuv_and( uint8_t *dest, uint8_t *src, int width, uint
                dest++;
                *dest = sample_mix( *dest, *src++, mix );
                dest++;
-               *alpha_a ++ = mix;
+               *alpha_a ++ = mix >> 8;
        }
 }
 
@@ -440,7 +440,7 @@ static void composite_line_yuv_xor( uint8_t *dest, uint8_t *src, int width, uint
                dest++;
                *dest = sample_mix( *dest, *src++, mix );
                dest++;
-               *alpha_a ++ = mix;
+               *alpha_a ++ = mix >> 8;
        }
 }