FS-7904 #resolve #fixed #comment fixed alpha image patching

diff --git a/src/switch_core_video.c b/src/switch_core_video.c
index d9336fd7dbd09767a781a51e4ca6daaa0a13ccef..e33291fde294442d46e5b4f1d172d0962c47a2c2 100644 (file)
--- a/src/switch_core_video.c
+++ b/src/switch_core_video.c
@@ -205,16 +205,24 @@ SWITCH_DECLARE(void) switch_img_patch(switch_image_t *IMG, switch_image_t *img,
                int max_h = MIN(img->d_h, IMG->d_h - abs(y));
                int j;
                uint8_t alpha;
-               switch_rgb_color_t *rgb_color;
+               switch_rgb_color_t *rgb;
 
                for (i = 0; i < max_h; i++) {
                        for (j = 0; j < max_w; j++) {
                                alpha = img->planes[SWITCH_PLANE_PACKED][i * img->stride[SWITCH_PLANE_PACKED] + j * 4];
-                               // printf("%d, %d alpha: %d\n", j, i, alpha);
 
-                               if (alpha > 127) { // todo: mux alpha with the underlying pixel ?
-                                       rgb_color = (switch_rgb_color_t *)(img->planes[SWITCH_PLANE_PACKED] + i * img->stride[SWITCH_PLANE_PACKED] + j * 4);
-                                       switch_img_draw_pixel(IMG, x + j, y + i, rgb_color);
+                               if (alpha > 0) {
+                                       switch_rgb_color_t RGB = { 0 };
+
+                                       switch_img_get_rgb_pixel(IMG, &RGB, x + j, y + i);
+                                       rgb = (switch_rgb_color_t *)(img->planes[SWITCH_PLANE_PACKED] + i * img->stride[SWITCH_PLANE_PACKED] + j * 4);
+
+                                       RGB.a = 255;
+                                       RGB.r = ((RGB.r * (255 - alpha)) >> 8) + ((rgb->r * alpha) >> 8);
+                                       RGB.g = ((RGB.g * (255 - alpha)) >> 8) + ((rgb->g * alpha) >> 8);
+                                       RGB.b = ((RGB.b * (255 - alpha)) >> 8) + ((rgb->b * alpha) >> 8);
+
+                                       switch_img_draw_pixel(IMG, x + j, y + i, &RGB);
                                }
                        }
                }