1 /*****************************************************************************
2 * i420_rgb8.c : YUV to bitmap RGB conversion module for vlc
3 *****************************************************************************
4 * Copyright (C) 2000 VideoLAN
5 * $Id: i420_rgb8.c,v 1.4 2002/03/19 00:30:44 sam Exp $
7 * Authors: Samuel Hocevar <sam@zoy.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
27 #include <math.h> /* exp(), pow() */
28 #include <errno.h> /* ENOMEM */
29 #include <string.h> /* strerror() */
30 #include <stdlib.h> /* malloc(), free() */
32 #include <videolan/vlc.h>
35 #include "video_output.h"
38 #include "i420_rgb_c.h"
40 static void SetOffset( int, int, int, int, boolean_t *, int *, int * );
42 /*****************************************************************************
43 * I420_RGB8: color YUV 4:2:0 to RGB 8 bpp
44 *****************************************************************************/
45 void _M( I420_RGB8 )( vout_thread_t *p_vout, picture_t *p_src,
48 /* We got this one from the old arguments */
49 u8 *p_pic = (u8*)p_dest->p->p_pixels;
50 u8 *p_y = p_src->Y_PIXELS;
51 u8 *p_u = p_src->U_PIXELS;
52 u8 *p_v = p_src->V_PIXELS;
54 boolean_t b_hscale; /* horizontal scaling type */
55 int i_vscale; /* vertical scaling type */
56 int i_x, i_y; /* horizontal and vertical indexes */
57 int i_real_y; /* y % 4 */
59 int i_scale_count; /* scale modulo counter */
60 int i_chroma_width = p_vout->render.i_width / 2; /* chroma width */
63 u8 * p_lookup = p_vout->chroma.p_sys->p_base;
65 /* Offset array pointer */
66 int * p_offset_start = p_vout->chroma.p_sys->p_offset;
69 /* The dithering matrices */
70 static int dither10[4] = { 0x0, 0x8, 0x2, 0xa };
71 static int dither11[4] = { 0xc, 0x4, 0xe, 0x6 };
72 static int dither12[4] = { 0x3, 0xb, 0x1, 0x9 };
73 static int dither13[4] = { 0xf, 0x7, 0xd, 0x5 };
75 static int dither20[4] = { 0x0, 0x10, 0x4, 0x14 };
76 static int dither21[4] = { 0x18, 0x8, 0x1c, 0xc };
77 static int dither22[4] = { 0x6, 0x16, 0x2, 0x12 };
78 static int dither23[4] = { 0x1e, 0xe, 0x1a, 0xa };
80 SetOffset( p_vout->render.i_width, p_vout->render.i_height,
81 p_vout->output.i_width, p_vout->output.i_height,
82 &b_hscale, &i_vscale, p_offset_start );
84 if( p_dest->p->b_margin )
86 i_right_margin = (p_dest->p->i_pitch - p_dest->p->i_visible_bytes);
96 i_scale_count = ( i_vscale == 1 ) ?
97 p_vout->output.i_height : p_vout->render.i_height;
98 for( i_y = 0, i_real_y = 0; i_y < p_vout->render.i_height; i_y++ )
100 /* Do horizontal and vertical scaling */
101 SCALE_WIDTH_DITHER( 420 );
102 SCALE_HEIGHT_DITHER( 420 );
106 /* Following functions are local */
108 /*****************************************************************************
109 * SetOffset: build offset array for conversion functions
110 *****************************************************************************
111 * This function will build an offset array used in later conversion functions.
112 * It will also set horizontal and vertical scaling indicators. The p_offset
113 * structure has interleaved Y and U/V offsets.
114 *****************************************************************************/
115 static void SetOffset( int i_width, int i_height, int i_pic_width,
116 int i_pic_height, boolean_t *pb_hscale,
117 int *pi_vscale, int *p_offset )
119 int i_x; /* x position in destination */
120 int i_scale_count; /* modulo counter */
123 * Prepare horizontal offset array
125 if( i_pic_width - i_width == 0 )
127 /* No horizontal scaling: YUV conversion is done directly to picture */
130 else if( i_pic_width - i_width > 0 )
134 /* Prepare scaling array for horizontal extension */
136 i_scale_count = i_pic_width;
137 for( i_x = i_width; i_x--; )
139 while( (i_scale_count -= i_width) > 0 )
145 *p_offset++ = i_dummy;
146 i_dummy = 1 - i_dummy;
147 i_scale_count += i_pic_width;
150 else /* if( i_pic_width - i_width < 0 ) */
155 /* Prepare scaling array for horizontal reduction */
157 i_scale_count = i_width;
158 for( i_x = i_pic_width; i_x--; )
161 while( (i_scale_count -= i_pic_width) > 0 )
165 *p_offset++ = i_jump;
166 *p_offset++ = ( i_jump += i_remainder ) >> 1;
167 i_remainder = i_jump & 1;
168 i_scale_count += i_width;
173 * Set vertical scaling indicator
175 if( i_pic_height - i_height == 0 )
179 else if( i_pic_height - i_height > 0 )
183 else /* if( i_pic_height - i_height < 0 ) */