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 1.7 2002/07/23 00:39:16 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 <errno.h> /* ENOMEM */
28 #include <string.h> /* strerror() */
29 #include <stdlib.h> /* malloc(), free() */
35 #include "i420_rgb_c.h"
37 static void SetOffset( int, int, int, int, vlc_bool_t *, int *, int * );
39 /*****************************************************************************
40 * I420_RGB8: color YUV 4:2:0 to RGB 8 bpp
41 *****************************************************************************/
42 void _M( I420_RGB8 )( vout_thread_t *p_vout, picture_t *p_src,
45 /* We got this one from the old arguments */
46 u8 *p_pic = (u8*)p_dest->p->p_pixels;
47 u8 *p_y = p_src->Y_PIXELS;
48 u8 *p_u = p_src->U_PIXELS;
49 u8 *p_v = p_src->V_PIXELS;
51 vlc_bool_t b_hscale; /* horizontal scaling type */
52 int i_vscale; /* vertical scaling type */
53 int i_x, i_y; /* horizontal and vertical indexes */
54 int i_real_y; /* y % 4 */
56 int i_scale_count; /* scale modulo counter */
57 int i_chroma_width = p_vout->render.i_width / 2; /* chroma width */
60 u8 * p_lookup = p_vout->chroma.p_sys->p_base;
62 /* Offset array pointer */
63 int * p_offset_start = p_vout->chroma.p_sys->p_offset;
66 /* The dithering matrices */
67 static int dither10[4] = { 0x0, 0x8, 0x2, 0xa };
68 static int dither11[4] = { 0xc, 0x4, 0xe, 0x6 };
69 static int dither12[4] = { 0x3, 0xb, 0x1, 0x9 };
70 static int dither13[4] = { 0xf, 0x7, 0xd, 0x5 };
72 static int dither20[4] = { 0x0, 0x10, 0x4, 0x14 };
73 static int dither21[4] = { 0x18, 0x8, 0x1c, 0xc };
74 static int dither22[4] = { 0x6, 0x16, 0x2, 0x12 };
75 static int dither23[4] = { 0x1e, 0xe, 0x1a, 0xa };
77 SetOffset( p_vout->render.i_width, p_vout->render.i_height,
78 p_vout->output.i_width, p_vout->output.i_height,
79 &b_hscale, &i_vscale, p_offset_start );
81 i_right_margin = p_dest->p->i_pitch - p_dest->p->i_visible_pitch;
86 i_scale_count = ( i_vscale == 1 ) ?
87 p_vout->output.i_height : p_vout->render.i_height;
88 for( i_y = 0, i_real_y = 0; i_y < p_vout->render.i_height; i_y++ )
90 /* Do horizontal and vertical scaling */
91 SCALE_WIDTH_DITHER( 420 );
92 SCALE_HEIGHT_DITHER( 420 );
96 /* Following functions are local */
98 /*****************************************************************************
99 * SetOffset: build offset array for conversion functions
100 *****************************************************************************
101 * This function will build an offset array used in later conversion functions.
102 * It will also set horizontal and vertical scaling indicators. The p_offset
103 * structure has interleaved Y and U/V offsets.
104 *****************************************************************************/
105 static void SetOffset( int i_width, int i_height, int i_pic_width,
106 int i_pic_height, vlc_bool_t *pb_hscale,
107 int *pi_vscale, int *p_offset )
109 int i_x; /* x position in destination */
110 int i_scale_count; /* modulo counter */
113 * Prepare horizontal offset array
115 if( i_pic_width - i_width == 0 )
117 /* No horizontal scaling: YUV conversion is done directly to picture */
120 else if( i_pic_width - i_width > 0 )
124 /* Prepare scaling array for horizontal extension */
126 i_scale_count = i_pic_width;
127 for( i_x = i_width; i_x--; )
129 while( (i_scale_count -= i_width) > 0 )
135 *p_offset++ = i_dummy;
136 i_dummy = 1 - i_dummy;
137 i_scale_count += i_pic_width;
140 else /* if( i_pic_width - i_width < 0 ) */
145 /* Prepare scaling array for horizontal reduction */
147 i_scale_count = i_width;
148 for( i_x = i_pic_width; i_x--; )
151 while( (i_scale_count -= i_pic_width) > 0 )
155 *p_offset++ = i_jump;
156 *p_offset++ = ( i_jump += i_remainder ) >> 1;
157 i_remainder = i_jump & 1;
158 i_scale_count += i_width;
163 * Set vertical scaling indicator
165 if( i_pic_height - i_height == 0 )
169 else if( i_pic_height - i_height > 0 )
173 else /* if( i_pic_height - i_height < 0 ) */