- int ret = 0;
- int width_src = 0, height_src = 0;
- int width_dest = 0, height_dest = 0;
- mlt_image_format format_src = mlt_image_yuv422, format_dest = mlt_image_yuv422;
- uint8_t *p_src, *p_dest;
- int i, j;
- int stride_src;
- int stride_dest;
- int x_src = 0, y_src = 0;
-
- // optimization point - no work to do
- if ( ( x < 0 && -x >= width_src ) || ( y < 0 && -y >= height_src ) )
- return ret;
-
- format_src = mlt_image_yuv422;
- format_dest = mlt_image_yuv422;
-
- //fprintf( stderr, "call get_image on frame a\n"), fflush( stderr );
- mlt_frame_get_image( this, &p_dest, &format_dest, &width_dest, &height_dest, 1 /* writable */ );
- //fprintf( stderr, "call get_image on frame b\n"), fflush( stderr );
- mlt_frame_get_image( that, &p_src, &format_src, &width_src, &height_src, 0 /* writable */ );
-
- //fprintf( stderr, "mlt_frame_composite_yuv %dx%d -> %dx%d\n", width_src, height_src, width_dest, height_dest );
- //fflush(stderr);
- //return ret;
- stride_src = width_src * 2;
- stride_dest = width_dest * 2;
-
- // crop overlay off the left edge of frame
- if ( x < 0 )
- {
- x_src = -x;
- width_src -= x_src;
- x = 0;
- }
-
- // crop overlay beyond right edge of frame
- else if ( x + width_src > width_dest )
- width_src = width_dest - x;
-
- // crop overlay off the top edge of the frame
- if ( y < 0 )
- {
- y_src = -y;
- height_src -= y_src;
- }
- // crop overlay below bottom edge of frame
- else if ( y + height_src > height_dest )
- height_src = height_dest - y;
-
- // offset pointer into overlay buffer based on cropping
- p_src += x_src * 2 + y_src * stride_src;
-
- // offset pointer into frame buffer based upon positive, even coordinates only!
-// if ( interlaced && y % 2 )
-// ++y;
- p_dest += ( x < 0 ? 0 : x ) * 2 + ( y < 0 ? 0 : y ) * stride_dest;
-
- // Get the alpha channel of the overlay
- uint8_t *p_alpha = mlt_frame_get_alpha_mask( that );
-
- // offset pointer into alpha channel based upon cropping
- if ( p_alpha )
- p_alpha += x_src + y_src * stride_src / 2;
-
- // now do the compositing only to cropped extents
- for ( i = 0; i < height_src; i++ )