* render.c : Philips OGT (SVCD Subtitle) renderer
*****************************************************************************
* Copyright (C) 2003 VideoLAN
- * $Id: render.c,v 1.7 2004/01/01 15:56:56 rocky Exp $
+ * $Id: render.c,v 1.8 2004/01/02 04:44:34 rocky Exp $
*
* Author: Rocky Bernstein
* based on code from:
struct subpicture_sys_t *p_sys = p_spu->p_sys;
dbg_print( (DECODE_DBG_CALL|DECODE_DBG_RENDER),
- "spu width: %d, height %d, pitch (%d, %d, %d)",
- p_spu->i_width, p_spu->i_height,
+ "spu width x height: (%dx%d), x-y (%d,%d), yuv pitch (%d,%d,%d)",
+ p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y,
p_pic->Y_PITCH, p_pic->U_PITCH, p_pic->V_PITCH );
- p_pixel_base = p_pic->p[Y_PLANE].p_pixels + p_spu->i_x + p_spu->i_width
- + p_pic->p[Y_PLANE].i_pitch * ( p_spu->i_y + p_spu->i_height );
+ p_pixel_base = p_pic->p[Y_PLANE].p_pixels + p_spu->i_x
+ + p_pic->p[Y_PLANE].i_pitch * p_spu->i_y;
- i_x_start = p_spu->i_width - p_sys->i_x_end;
- i_y_start = p_pic->p[Y_PLANE].i_pitch
- * (p_spu->i_height - p_sys->i_y_end );
+ i_x_start = p_sys->i_x_start;
+ i_y_start = p_pic->p[Y_PLANE].i_pitch * p_sys->i_y_start;
- i_x_end = p_spu->i_width - p_sys->i_x_start;
- i_y_end = p_pic->p[Y_PLANE].i_pitch
- * (p_spu->i_height - p_sys->i_y_start );
+ i_x_end = p_sys->i_x_end;
+ i_y_end = p_pic->p[Y_PLANE].i_pitch * p_sys->i_y_end;
p_source = (ogt_yuvt_t *)p_sys->p_data;
/* Draw until we reach the bottom of the subtitle */
- for( i_y = p_spu->i_height * p_pic->p[Y_PLANE].i_pitch ;
- i_y ;
- i_y -= p_pic->p[Y_PLANE].i_pitch )
+ for( i_y = 0;
+ i_y < p_spu->i_height * p_pic->p[Y_PLANE].i_pitch ;
+ i_y += p_pic->p[Y_PLANE].i_pitch )
{
/* printf("+++begin line: %d,\n", i++); */
/* Draw until we reach the end of the line */
- for( i_x = p_spu->i_width ; i_x ; i_x--, p_source++ )
+ for( i_x = 0; i_x < p_spu->i_width; i_x++, p_source++ )
{
-
if( b_crop
&& ( i_x < i_x_start || i_x > i_x_end
|| i_y < i_y_start || i_y > i_y_end ) )
/* Completely opaque. Completely overwrite underlying
pixel with subtitle pixel. */
- uint8_t *p_pixel = p_pixel_base - i_x - i_y;
- uint16_t i_colprecomp =
- (uint16_t) ( p_source->plane[Y_PLANE] * MAX_ALPHA );
- *p_pixel = i_colprecomp >> ALPHA_SCALEDOWN;
+ /* This is the location that's going to get changed.*/
+ uint8_t *p_pixel = p_pixel_base + i_x + i_y;
+
+ *p_pixel = p_source->plane[Y_PLANE];
break;
}
{
/* Blend in underlying pixel subtitle pixel. */
- /* To be able to scale correctly for full opaqueness, we
- add 1 to the alpha. This means alpha value 0 won't
- be completely transparent and is not correct, but
- that's handled in a special case above anyway. */
-
- uint8_t *p_pixel = p_pixel_base - i_x - i_y;
- uint16_t i_colprecomp =
- (uint16_t) ( p_source->plane[Y_PLANE]
- * (uint16_t) (p_source->s.t+1) );
- uint16_t i_destalpha = MAX_ALPHA - p_source->s.t;
+ /* This is the location that's going to get changed.*/
+ uint8_t *p_pixel = p_pixel_base + i_x + i_y;
+
+ /* This is the weighted part of the subtitle. The
+ color plane is 8 bits and transparancy is 4 bits so
+ when multiplied we get up to 12 bits.
+ */
+ uint16_t i_sub_color =
+ (uint16_t) ( p_source->plane[Y_PLANE] *
+ (uint16_t) (p_source->s.t) );
+
+ /* This is the weighted part of the underlying pixel.
+ For the same reasons above, the result is up to 12
+ bits. However since the transparancies are
+ inverses, the sum of i_sub_color and i_pixel_color
+ will not exceed 12 bits.
+ */
+ uint16_t i_pixel_color =
+ (uint16_t) ( *p_pixel *
+ (uint16_t) (MAX_ALPHA - p_source->s.t) ) ;
- *p_pixel = ( i_colprecomp +
- (uint16_t) (*p_pixel) * i_destalpha )
- >> ALPHA_SCALEDOWN;
+ /* Scale the 12-bit result back down to 8 bits. A
+ precise scaling after adding the two components,
+ would divide by one less than a power of 2. However
+ to simplify and speed things we use a power of
+ 2. This means the boundaries (either all
+ transparent and all opaque) aren't handled properly.
+ But we deal with them in special cases above. */
+
+ *p_pixel = ( i_sub_color + i_pixel_color ) >> 4;
break;
}
}
-#if FIXED
- for ( i_plane = U_PLANE; i_plane <= U_PLANE ; i_plane++ )
+#if 0
+ for ( i_plane = U_PLANE; i_plane <= V_PLANE ; i_plane++ )
{
- p_pixel_base = p_pic->p[i_plane].p_pixels
- + ( p_spu->i_x + p_spu->i_width
- + p_pic->p[i_plane].i_pitch * (p_spu->i_y + p_spu->i_height) )/2 ;
+ p_pixel_base = p_pic->p[i_plane].p_pixels + p_spu->i_x / 2
+ + p_pic->p[i_plane].i_pitch * p_spu->i_y / 2;
- i_x_start = (p_spu->i_width - p_sys->i_x_end) >> 1;
- i_y_start = p_pic->p[i_plane].i_pitch
- * (p_spu->i_height - p_sys->i_y_end );
-
- i_x_end = (p_spu->i_width - p_sys->i_x_start ) >> 1;
- i_y_end = p_pic->p[i_plane].i_pitch
- * (p_spu->i_height - p_sys->i_y_start );
+ i_x_start = p_sys->i_x_start / 2;
+ i_y_start = p_pic->p[Y_PLANE].i_pitch * p_sys->i_y_start;
+
+ i_x_end = p_sys->i_x_end / 2;
+ i_y_end = p_pic->p[Y_PLANE].i_pitch * p_sys->i_y_end;
p_source = (ogt_yuvt_t *)p_sys->p_data;
/* Draw until we reach the bottom of the subtitle */
- for( i_y = p_spu->i_height * p_pic->p[i_plane].i_pitch ;
- i_y > 0;
- i_y -= p_pic->p[i_plane].i_pitch )
+ for( i_y = 0;
+ i_y < p_spu->i_height * p_pic->p[i_plane].i_pitch ;
+ i_y += p_pic->p[i_plane].i_pitch )
{
- vlc_bool_t high_nibble = VLC_TRUE;
-
/* printf("+++begin line: %d,\n", i++); */
/* Draw until we reach the end of the line */
- for( i_x = p_spu->i_width / 2 ; i_x > 0 ; i_x--, p_source ++ )
+ for( i_x = 0; i_x < p_spu->i_width; i_x += 2, p_source += 2 )
{
- high_nibble = !high_nibble;
-
if( b_crop
&& ( i_x < i_x_start || i_x > i_x_end
|| i_y < i_y_start || i_y > i_y_end ) )
case 0x00:
/* Completely transparent. Don't change pixel. */
break;
-
+
+ default:
case MAX_ALPHA:
{
/* Completely opaque. Completely overwrite underlying
pixel with subtitle pixel. */
- uint8_t *p_pixel = p_pixel_base - (i_x - i_y) / 2;
- uint16_t i_colprecomp =
- (uint16_t) (p_source->plane[i_plane] >> 4);
-
- if (high_nibble)
- *p_pixel = (i_colprecomp << 4) | ((*p_pixel) & 0x0f);
- else
- *p_pixel = (i_colprecomp) | ((*p_pixel) & 0xf0);
-
+ /* This is the location that's going to get changed.*/
+ uint8_t *p_pixel = p_pixel_base + i_y/2 + i_x/2;
+ uint8_t alpha = p_source->plane[i_plane];
+ *p_pixel = ( ( *p_pixel * ( 0xFF - alpha ) ) >> 8 ) +
+ ( 0x80 * alpha >> 8 );
break;
}
-
- default:
+
+#if 0
{
/* Blend in underlying pixel subtitle pixel. */
alpha value 0 won't be completely transparent and
is not correct, but that's handled in a special
case above anyway. */
- uint8_t *p_pixel = p_pixel_base - (i_x - i_y) / 2;
- uint16_t i_colprecomp = (uint16_t)
- (p_source->plane[i_plane]
- * (uint16_t) (p_source->s.t+1)) >> (4+4);
- uint16_t i_destalpha = (MAX_ALPHA - p_source->s.t) >> 4;
-
- if (high_nibble)
- *p_pixel =
- (( (i_colprecomp) +
- (((uint16_t) *p_pixel * i_destalpha) & 0x0f) ) <<4)
- | ((*p_pixel) & 0x0f);
+ uint8_t *p_pixel = p_pixel_base + i_y/2 + i_x/2;
+ uint8_t low_val = *p_pixel & 0x0f;
+ uint8_t high_val = *p_pixel & 0xf0 >> 4;
+ uint16_t i_colprecomp = (p_source->plane[i_plane]
+ * (uint16_t) (p_source->s.t+1)) >> 4;
+ uint8_t i_destalpha = MAX_ALPHA - p_source->s.t;
+ uint16_t new_low = ( i_colprecomp + low_val*i_destalpha )
+ / 2;
+ uint16_t new_high;
- else
- *p_pixel =
- ( (i_colprecomp) +
- (((uint16_t) *p_pixel * i_destalpha) & 0x0f) )
- | ((*p_pixel) & 0xf0);
+ p_source++;
+ i_colprecomp = (p_source->plane[i_plane]
+ * (uint16_t) (p_source->s.t+1)) >> 4;
+ i_destalpha = MAX_ALPHA - p_source->s.t;
+ new_high = ( i_colprecomp + high_val*i_destalpha ) / 2;
+
+ *p_pixel = (new_high << 4) | new_low;
break;
}
+#endif
}
}
}
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