diff options
Diffstat (limited to 'libass/ass.h')
| -rw-r--r-- | libass/ass.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/libass/ass.h b/libass/ass.h index b92960a..3c8c1f6 100644 --- a/libass/ass.h +++ b/libass/ass.h @@ -30,11 +30,21 @@ /* Libass renderer object. Contents are private. */ typedef struct ass_renderer_s ass_renderer_t; -/* A linked list of images produced by ass renderer. */ +/* + * A linked list of images produced by an ass renderer. + * + * These images have to be rendered in-order for the correct screen + * composition. The libass renderer clips these bitmaps to the frame size. + * w/h can be zero, in this case the bitmap should not be rendered at all. + * The last bitmap row is not guaranteed to be padded up to stride size, + * e.g. in the worst case a bitmap has the size stride * (h - 1) + w. + */ typedef struct ass_image_s { int w, h; // Bitmap width/height int stride; // Bitmap stride unsigned char *bitmap; // 1bpp stride*h alpha buffer + // Note: the last row may not be padded to + // bitmap stride! uint32_t color; // Bitmap color and alpha, RGBA int dst_x, dst_y; // Bitmap placement inside the video frame |