/src/vlc/modules/codec/cdg.c

Source
/*****************************************************************************
 * cdg.c: CDG decoder module
 *****************************************************************************
 * Copyright (C) 2007 Laurent Aimar
 *
 * Authors: Laurent Aimar <fenrir # via.ecp.fr>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_codec.h>

/*****************************************************************************
 * decoder_sys_t : decoder descriptor
 *****************************************************************************/

/* The screen size */
#define CDG_SCREEN_WIDTH 300u
#define CDG_SCREEN_HEIGHT 216u

/* The border of the screen size */
#define CDG_SCREEN_BORDER_WIDTH 6u
#define CDG_SCREEN_BORDER_HEIGHT 12u

/* The display part */
#define CDG_DISPLAY_WIDTH  (CDG_SCREEN_WIDTH-2*CDG_SCREEN_BORDER_WIDTH)
#define CDG_DISPLAY_HEIGHT (CDG_SCREEN_HEIGHT-2*CDG_SCREEN_BORDER_HEIGHT)

#define CDG_SCREEN_PITCH CDG_SCREEN_WIDTH

typedef struct
{
    uint8_t  color[16][3];
    unsigned i_offseth;
    unsigned i_offsetv;
    uint8_t  screen[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
    uint8_t  *p_screen;

    int      i_packet;
} decoder_sys_t;

#define CDG_PACKET_SIZE 24u

#define CDG_COLOR_R_SHIFT  0
#define CDG_COLOR_G_SHIFT  8
#define CDG_COLOR_B_SHIFT 16

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  Open ( vlc_object_t * );

static int Decode( decoder_t *, block_t * );

static int DecodePacket( decoder_sys_t *p_cdg, uint8_t *p_buffer, int i_buffer );
static void Flush( decoder_t * );
static int Render( decoder_sys_t *p_cdg, picture_t *p_picture );

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
vlc_module_begin ()
    set_subcategory( SUBCAT_INPUT_VCODEC )
    set_description( N_("CDG video decoder") )
    set_capability( "video decoder", 1000 )
    set_callback( Open )
    add_shortcut( "cdg" )
vlc_module_end ()

/*****************************************************************************
 * Open: probe the decoder and return score
 *****************************************************************************/
static int Open( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys;

    if( p_dec->fmt_in->i_codec != VLC_CODEC_CDG )
        return VLC_EGENERIC;

    /* Allocate the memory needed to store the decoder's structure */
    p_dec->p_sys = p_sys = vlc_obj_calloc( p_this, 1, sizeof(decoder_sys_t) );
    if( !p_sys )
        return VLC_ENOMEM;

    /* Init */
    p_sys->p_screen = p_sys->screen;
    p_sys->i_packet = 0;

    /* Set output properties
     * TODO maybe it would be better to use RV16 or RV24 ? */
    p_dec->fmt_out.i_codec =
    p_dec->fmt_out.video.i_chroma = VLC_CODEC_XBGR;
    p_dec->fmt_out.video.i_width = CDG_DISPLAY_WIDTH;
    p_dec->fmt_out.video.i_height = CDG_DISPLAY_HEIGHT;
    p_dec->fmt_out.video.i_sar_num = 1;
    p_dec->fmt_out.video.i_sar_den = 1;

    /* Set callbacks */
    p_dec->pf_decode = Decode;
    p_dec->pf_flush  = Flush;

    return VLC_SUCCESS;
}

/*****************************************************************************
 * Flush:
 *****************************************************************************/
static void Flush( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    p_sys->i_packet = 0;
}

/****************************************************************************
 * Decode: the whole thing
 ****************************************************************************
 * This function must be fed with a complete compressed frame.
 ****************************************************************************/
static int Decode( decoder_t *p_dec, block_t *p_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    picture_t *p_pic = NULL;

    if( !p_block ) /* No Drain */
        return VLCDEC_SUCCESS;

    if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
    {
        Flush( p_dec );
        goto exit;
    }

    /* Decode packet */
    while( p_block->i_buffer >= CDG_PACKET_SIZE )
    {
        DecodePacket( p_sys, p_block->p_buffer, CDG_PACKET_SIZE );
        p_block->i_buffer -= CDG_PACKET_SIZE;
        p_block->p_buffer += CDG_PACKET_SIZE;
    }

    /* Only display 25 frame per second (there is 75 packets per second) */
    if( (p_sys->i_packet%3) == 1 && p_block->i_pts == p_block->i_dts )
    {
        /* Get a new picture */
        if( decoder_UpdateVideoFormat( p_dec ) )
            goto exit;
        p_pic = decoder_NewPicture( p_dec );
        if( !p_pic )
            goto exit;

        Render( p_sys, p_pic );
        p_pic->date = p_block->i_pts != VLC_TICK_INVALID ? p_block->i_pts : p_block->i_dts;
    }

exit:
    block_Release( p_block );
    if( p_pic != NULL )
        decoder_QueueVideo( p_dec, p_pic );
    return VLCDEC_SUCCESS;
}

/*****************************************************************************
 * Decoder
 *****************************************************************************/
static void ScreenFill( decoder_sys_t *p_cdg, int sx, int sy, int dx, int dy, int c )
{
    int x, y;
    for( y = sy; y < sy+dy; y++ )
        for( x = sx; x < sx+dx; x++ )
            p_cdg->p_screen[y*CDG_SCREEN_PITCH+x] = c;
}
static int DecodeMemoryPreset( decoder_sys_t *p_cdg, const uint8_t *p_data )
{
    const int i_color = p_data[0]&0x0f;
#if 0
    const int i_repeat= p_data[1]&0x0f;
#endif
    /* if i_repeat > 0 we could ignore it if we have a reliable stream */
    ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, i_color );
    return 0;
}
static int DecodeBorderPreset( decoder_sys_t *p_cdg, const uint8_t *p_data )
{
    const int i_color = p_data[0]&0x0f;

    /* */
    ScreenFill( p_cdg,   0,   0,
                CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
    ScreenFill( p_cdg,   0, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT,
                CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
    ScreenFill( p_cdg,   0, CDG_SCREEN_BORDER_HEIGHT,
                CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
    ScreenFill( p_cdg,   CDG_SCREEN_WIDTH-CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_BORDER_HEIGHT,
                CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
    return 0;
}

static int DecodeLoadColorTable( decoder_sys_t *p_cdg, const uint8_t *p_data, int i_base )
{
    int n;
    for( n = 0; n < 8; n++ )
    {
        const int c = ((p_data[2*n+0] << 8) | p_data[2*n+1]);
        const int r = (c >> 10)&0x0f;
        const int g = ((c >> 6)&0x0c) | ((c >> 4)&0x03);
        const int b = c &0x0f;

        p_cdg->color[i_base+n][0] = r << 4;
        p_cdg->color[i_base+n][1] = g << 4;
        p_cdg->color[i_base+n][2] = b << 4;
    }
    return 0;
}
static int DecodeTileBlock( decoder_sys_t *p_cdg, const uint8_t *p_data, int doXor )
{
    int p_color[2];
    int sx, sy;
    int x, y;

    p_color[0] = p_data[0] & 0x0f;
    p_color[1] = p_data[1] & 0x0f;

    sy = (p_data[2] & 0x1f)*12;
    sx = (p_data[3] & 0x3f)*6;

    for( y = 0; y < 12; y++ )
    {
        for( x = 0; x < 6; x++ )
        {
            const int idx = ( p_data[4+y] >> (5-x) ) & 0x01;

            unsigned index = (sy+y)*CDG_SCREEN_PITCH+(sx+x);
            if( index >= CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT )
                return 0;

            uint8_t *p = &p_cdg->p_screen[index];

            if( doXor )
                *p ^= p_color[idx];
            else
                *p = p_color[idx];
        }
    }
    return 0;
}

static int DecodeScroll( decoder_sys_t *p_cdg, const uint8_t *p_data, int b_copy )
{
    uint8_t copy[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];

    uint8_t color = p_data[0]&0x0f;
    int i_shifth;
    int i_shiftv;

    /* */
    p_cdg->i_offseth = p_data[1]&0x7;
    if( p_cdg->i_offseth >= CDG_SCREEN_BORDER_WIDTH )
        p_cdg->i_offseth = CDG_SCREEN_BORDER_WIDTH-1;

    p_cdg->i_offsetv = p_data[2]&0xf;
    if( p_cdg->i_offsetv >= CDG_SCREEN_BORDER_HEIGHT )
        p_cdg->i_offsetv = CDG_SCREEN_BORDER_HEIGHT-1;

    /* */
    switch( (p_data[1] >> 4)&0x3 )
    {
    case 0x01: i_shifth =  6; break;
    case 0x02: i_shifth = -6; break;
    default:
        i_shifth = 0;
        break;
    }
    switch( (p_data[2] >> 4)&0x3 )
    {
    case 0x01: i_shiftv = 12; break;
    case 0x02: i_shiftv =-12; break;
    default:
        i_shiftv = 0;
        break;
    }

    if( i_shifth == 0 && i_shiftv == 0 )
        return 0;

    /* Make a copy of the screen */
    memcpy( copy, p_cdg->screen, sizeof(p_cdg->screen) );

    /* Fill the uncovered part XXX way too much */
    ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, color );

    /* Copy back */
    for( unsigned y = 0; y < CDG_SCREEN_HEIGHT; y++ )
    {
        int dy = i_shiftv + y;
        for( unsigned x = 0; x < CDG_SCREEN_WIDTH; x++ )
        {
            int dx = i_shifth + x;

            if( b_copy )
            {
                dy = (dy + CDG_SCREEN_HEIGHT) % CDG_SCREEN_HEIGHT;
                dx = (dx + CDG_SCREEN_WIDTH ) % CDG_SCREEN_WIDTH;
            }
            else
            {
                if( dy < 0 || (unsigned)dy >= CDG_SCREEN_HEIGHT ||
                    dx < 0 || (unsigned)dx >= CDG_SCREEN_WIDTH )
                    continue;
            }
            p_cdg->screen[dy*CDG_SCREEN_PITCH+dx] = copy[y*CDG_SCREEN_PITCH+x];
        }
    }
    /* */
    //CdgDebug( CDG_LOG_WARNING, "DecodeScroll: color=%d ch=%d oh=%d cv=%d ov=%d\n copy=%d\n", color, i_shifth, p_cdg->i_offseth, i_shiftv, p_cdg->i_offsetv, b_copy );
    return 0;
}

static int DecodePacket( decoder_sys_t *p_cdg, uint8_t *p_buffer, int i_buffer )
{
    const int i_cmd = p_buffer[0] & 0x3f;
    const int i_instruction = p_buffer[1] & 0x3f;
    const uint8_t *p_data = &p_buffer[4];

    if( i_buffer != CDG_PACKET_SIZE )
        return -1;

    p_cdg->i_packet++;

    /* Handle CDG command only */
    if( i_cmd != 0x09 )
        return 0;

    switch( i_instruction )
    {
        case 1:
            DecodeMemoryPreset( p_cdg, p_data );
            break;
        case 2:
            DecodeBorderPreset( p_cdg, p_data );
            break;
        case 6:
            DecodeTileBlock( p_cdg, p_data, 0 );
            break;
        case 20:
            DecodeScroll( p_cdg, p_data, 0 );
            break;
        case 24:
            DecodeScroll( p_cdg, p_data, 1 );
            break;
        case 28:
            /* FIXME what to do about that one ? */
            //CdgDebug( CDG_LOG_WARNING, "DecodeDefineTransparentColor not implemented\n" );
            //DecodeDefineTransparentColor( p_cdg, p_data );
            break;
        case 30:
            DecodeLoadColorTable( p_cdg, p_data, 0 );
            break;
        case 31:
            DecodeLoadColorTable( p_cdg, p_data, 8 );
            break;
        case 38:
            DecodeTileBlock( p_cdg, p_data, 1 );
            break;
        default:
            break;
    }
    return 0;
}

static void RenderPixel( picture_t *p_picture, int x, int y, uint32_t c )
{
    const int i_plane = 0;
    const int i_pitch = p_picture->p[i_plane].i_pitch;
    uint32_t *s = (uint32_t*)&p_picture->p[i_plane].p_pixels[y*i_pitch + x*sizeof(uint32_t)];
    *s = c;
}
static uint32_t RenderRGB( int r, int g, int b )
{
    return ( r << CDG_COLOR_R_SHIFT ) | ( g << CDG_COLOR_G_SHIFT ) | ( b << CDG_COLOR_B_SHIFT );
}

static int Render( decoder_sys_t *p_cdg, picture_t *p_picture )
{
    for( unsigned y = 0; y < CDG_DISPLAY_HEIGHT; y++ )
    {
        for( unsigned x = 0; x < CDG_DISPLAY_WIDTH; x++ )
        {
            const int sx = x + p_cdg->i_offseth + CDG_SCREEN_BORDER_WIDTH;
            const int sy = y + p_cdg->i_offsetv + CDG_SCREEN_BORDER_HEIGHT;
            uint8_t cidx = p_cdg->p_screen[sy*CDG_SCREEN_PITCH +sx];
            uint8_t r = p_cdg->color[cidx][0];
            uint8_t g = p_cdg->color[cidx][1];
            uint8_t b = p_cdg->color[cidx][2];

            RenderPixel( p_picture, x, y, RenderRGB( r, g, b ) );
        }
    }
    return 0;
}


Coverage Report

Created: 2026-03-07 07:40

Line	Count	Source
1		/*****************************************************************************
2		* cdg.c: CDG decoder module
3		*****************************************************************************
4		* Copyright (C) 2007 Laurent Aimar
5		*
6		* Authors: Laurent Aimar <fenrir # via.ecp.fr>
7		*
8		* This program is free software; you can redistribute it and/or modify it
9		* under the terms of the GNU Lesser General Public License as published by
10		* the Free Software Foundation; either version 2.1 of the License, or
11		* (at your option) any later version.
12		*
13		* This program is distributed in the hope that it will be useful,
14		* but WITHOUT ANY WARRANTY; without even the implied warranty of
15		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16		* GNU Lesser General Public License for more details.
17		*
18		* You should have received a copy of the GNU Lesser General Public License
19		* along with this program; if not, write to the Free Software Foundation,
20		* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
21		*****************************************************************************/
22
23		/*****************************************************************************
24		* Preamble
25		*****************************************************************************/
26		#ifdef HAVE_CONFIG_H
27		# include "config.h"
28		#endif
29
30		#include <vlc_common.h>
31		#include <vlc_plugin.h>
32		#include <vlc_codec.h>
33
34		/*****************************************************************************
35		* decoder_sys_t : decoder descriptor
36		*****************************************************************************/
37
38		/* The screen size */
39	0	#define CDG_SCREEN_WIDTH 300u
40	0	#define CDG_SCREEN_HEIGHT 216u
41
42		/* The border of the screen size */
43	0	#define CDG_SCREEN_BORDER_WIDTH 6u
44	0	#define CDG_SCREEN_BORDER_HEIGHT 12u
45
46		/* The display part */
47	0	#define CDG_DISPLAY_WIDTH (CDG_SCREEN_WIDTH-2*CDG_SCREEN_BORDER_WIDTH)
48	0	#define CDG_DISPLAY_HEIGHT (CDG_SCREEN_HEIGHT-2*CDG_SCREEN_BORDER_HEIGHT)
49
50	0	#define CDG_SCREEN_PITCH CDG_SCREEN_WIDTH
51
52		typedef struct
53		{
54		uint8_t color[16][3];
55		unsigned i_offseth;
56		unsigned i_offsetv;
57		uint8_t screen[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
58		uint8_t *p_screen;
59
60		int i_packet;
61		} decoder_sys_t;
62
63	0	#define CDG_PACKET_SIZE 24u
64
65	0	#define CDG_COLOR_R_SHIFT 0
66	0	#define CDG_COLOR_G_SHIFT 8
67	0	#define CDG_COLOR_B_SHIFT 16
68
69		/*****************************************************************************
70		* Local prototypes
71		*****************************************************************************/
72		static int Open ( vlc_object_t * );
73
74		static int Decode( decoder_t , block_t );
75
76		static int DecodePacket( decoder_sys_t p_cdg, uint8_t p_buffer, int i_buffer );
77		static void Flush( decoder_t * );
78		static int Render( decoder_sys_t p_cdg, picture_t p_picture );
79
80		/*****************************************************************************
81		* Module descriptor
82		*****************************************************************************/
83	104	vlc_module_begin ()
84	52	set_subcategory( SUBCAT_INPUT_VCODEC )
85	52	set_description( N_("CDG video decoder") )
86	52	set_capability( "video decoder", 1000 )
87	52	set_callback( Open )
88	52	add_shortcut( "cdg" )
89	52	vlc_module_end ()
90
91		/*****************************************************************************
92		* Open: probe the decoder and return score
93		*****************************************************************************/
94		static int Open( vlc_object_t *p_this )
95		{
96		decoder_t p_dec = (decoder_t)p_this;
97		decoder_sys_t *p_sys;
98
99		if( p_dec->fmt_in->i_codec != VLC_CODEC_CDG )
100		return VLC_EGENERIC;
101
102		/* Allocate the memory needed to store the decoder's structure */
103		p_dec->p_sys = p_sys = vlc_obj_calloc( p_this, 1, sizeof(decoder_sys_t) );
104		if( !p_sys )
105		return VLC_ENOMEM;
106
107		/* Init */
108		p_sys->p_screen = p_sys->screen;
109		p_sys->i_packet = 0;
110
111		/* Set output properties
112		* TODO maybe it would be better to use RV16 or RV24 ? */
113		p_dec->fmt_out.i_codec =
114		p_dec->fmt_out.video.i_chroma = VLC_CODEC_XBGR;
115		p_dec->fmt_out.video.i_width = CDG_DISPLAY_WIDTH;
116		p_dec->fmt_out.video.i_height = CDG_DISPLAY_HEIGHT;
117		p_dec->fmt_out.video.i_sar_num = 1;
118		p_dec->fmt_out.video.i_sar_den = 1;
119
120		/* Set callbacks */
121		p_dec->pf_decode = Decode;
122		p_dec->pf_flush = Flush;
123
124		return VLC_SUCCESS;
125		}
126
127		/*****************************************************************************
128		* Flush:
129		*****************************************************************************/
130		static void Flush( decoder_t *p_dec )
131	0	{
132	0	decoder_sys_t *p_sys = p_dec->p_sys;
133
134	0	p_sys->i_packet = 0;
135	0	}
136
137		/****************************************************************************
138		* Decode: the whole thing
139		****************************************************************************
140		* This function must be fed with a complete compressed frame.
141		****************************************************************************/
142		static int Decode( decoder_t p_dec, block_t p_block )
143	0	{
144	0	decoder_sys_t *p_sys = p_dec->p_sys;
145	0	picture_t *p_pic = NULL;
146
147	0	if( !p_block ) /* No Drain */
148	0	return VLCDEC_SUCCESS;
149
150	0	if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
151	0	{
152	0	Flush( p_dec );
153	0	goto exit;
154	0	}
155
156		/* Decode packet */
157	0	while( p_block->i_buffer >= CDG_PACKET_SIZE )
158	0	{
159	0	DecodePacket( p_sys, p_block->p_buffer, CDG_PACKET_SIZE );
160	0	p_block->i_buffer -= CDG_PACKET_SIZE;
161	0	p_block->p_buffer += CDG_PACKET_SIZE;
162	0	}
163
164		/* Only display 25 frame per second (there is 75 packets per second) */
165	0	if( (p_sys->i_packet%3) == 1 && p_block->i_pts == p_block->i_dts )
166	0	{
167		/* Get a new picture */
168	0	if( decoder_UpdateVideoFormat( p_dec ) )
169	0	goto exit;
170	0	p_pic = decoder_NewPicture( p_dec );
171	0	if( !p_pic )
172	0	goto exit;
173
174	0	Render( p_sys, p_pic );
175	0	p_pic->date = p_block->i_pts != VLC_TICK_INVALID ? p_block->i_pts : p_block->i_dts;
176	0	}
177
178	0	exit:
179	0	block_Release( p_block );
180	0	if( p_pic != NULL )
181	0	decoder_QueueVideo( p_dec, p_pic );
182	0	return VLCDEC_SUCCESS;
183	0	}
184
185		/*****************************************************************************
186		* Decoder
187		*****************************************************************************/
188		static void ScreenFill( decoder_sys_t *p_cdg, int sx, int sy, int dx, int dy, int c )
189	0	{
190	0	int x, y;
191	0	for( y = sy; y < sy+dy; y++ )
192	0	for( x = sx; x < sx+dx; x++ )
193	0	p_cdg->p_screen[y*CDG_SCREEN_PITCH+x] = c;
194	0	}
195		static int DecodeMemoryPreset( decoder_sys_t p_cdg, const uint8_t p_data )
196	0	{
197	0	const int i_color = p_data[0]&0x0f;
198		#if 0
199		const int i_repeat= p_data[1]&0x0f;
200		#endif
201		/* if i_repeat > 0 we could ignore it if we have a reliable stream */
202	0	ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, i_color );
203	0	return 0;
204	0	}
205		static int DecodeBorderPreset( decoder_sys_t p_cdg, const uint8_t p_data )
206	0	{
207	0	const int i_color = p_data[0]&0x0f;
208
209		/* */
210	0	ScreenFill( p_cdg, 0, 0,
211	0	CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
212	0	ScreenFill( p_cdg, 0, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT,
213	0	CDG_SCREEN_WIDTH, CDG_SCREEN_BORDER_HEIGHT, i_color );
214	0	ScreenFill( p_cdg, 0, CDG_SCREEN_BORDER_HEIGHT,
215	0	CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
216	0	ScreenFill( p_cdg, CDG_SCREEN_WIDTH-CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_BORDER_HEIGHT,
217	0	CDG_SCREEN_BORDER_WIDTH, CDG_SCREEN_HEIGHT-CDG_SCREEN_BORDER_HEIGHT, i_color );
218	0	return 0;
219	0	}
220
221		static int DecodeLoadColorTable( decoder_sys_t p_cdg, const uint8_t p_data, int i_base )
222	0	{
223	0	int n;
224	0	for( n = 0; n < 8; n++ )
225	0	{
226	0	const int c = ((p_data[2n+0] << 8) \| p_data[2n+1]);
227	0	const int r = (c >> 10)&0x0f;
228	0	const int g = ((c >> 6)&0x0c) \| ((c >> 4)&0x03);
229	0	const int b = c &0x0f;
230
231	0	p_cdg->color[i_base+n][0] = r << 4;
232	0	p_cdg->color[i_base+n][1] = g << 4;
233	0	p_cdg->color[i_base+n][2] = b << 4;
234	0	}
235	0	return 0;
236	0	}
237		static int DecodeTileBlock( decoder_sys_t p_cdg, const uint8_t p_data, int doXor )
238	0	{
239	0	int p_color[2];
240	0	int sx, sy;
241	0	int x, y;
242
243	0	p_color[0] = p_data[0] & 0x0f;
244	0	p_color[1] = p_data[1] & 0x0f;
245
246	0	sy = (p_data[2] & 0x1f)*12;
247	0	sx = (p_data[3] & 0x3f)*6;
248
249	0	for( y = 0; y < 12; y++ )
250	0	{
251	0	for( x = 0; x < 6; x++ )
252	0	{
253	0	const int idx = ( p_data[4+y] >> (5-x) ) & 0x01;
254
255	0	unsigned index = (sy+y)*CDG_SCREEN_PITCH+(sx+x);
256	0	if( index >= CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT )
257	0	return 0;
258
259	0	uint8_t *p = &p_cdg->p_screen[index];
260
261	0	if( doXor )
262	0	*p ^= p_color[idx];
263	0	else
264	0	*p = p_color[idx];
265	0	}
266	0	}
267	0	return 0;
268	0	}
269
270		static int DecodeScroll( decoder_sys_t p_cdg, const uint8_t p_data, int b_copy )
271	0	{
272	0	uint8_t copy[CDG_SCREEN_PITCH*CDG_SCREEN_HEIGHT];
273
274	0	uint8_t color = p_data[0]&0x0f;
275	0	int i_shifth;
276	0	int i_shiftv;
277
278		/* */
279	0	p_cdg->i_offseth = p_data[1]&0x7;
280	0	if( p_cdg->i_offseth >= CDG_SCREEN_BORDER_WIDTH )
281	0	p_cdg->i_offseth = CDG_SCREEN_BORDER_WIDTH-1;
282
283	0	p_cdg->i_offsetv = p_data[2]&0xf;
284	0	if( p_cdg->i_offsetv >= CDG_SCREEN_BORDER_HEIGHT )
285	0	p_cdg->i_offsetv = CDG_SCREEN_BORDER_HEIGHT-1;
286
287		/* */
288	0	switch( (p_data[1] >> 4)&0x3 )
289	0	{
290	0	case 0x01: i_shifth = 6; break;
291	0	case 0x02: i_shifth = -6; break;
292	0	default:
293	0	i_shifth = 0;
294	0	break;
295	0	}
296	0	switch( (p_data[2] >> 4)&0x3 )
297	0	{
298	0	case 0x01: i_shiftv = 12; break;
299	0	case 0x02: i_shiftv =-12; break;
300	0	default:
301	0	i_shiftv = 0;
302	0	break;
303	0	}
304
305	0	if( i_shifth == 0 && i_shiftv == 0 )
306	0	return 0;
307
308		/* Make a copy of the screen */
309	0	memcpy( copy, p_cdg->screen, sizeof(p_cdg->screen) );
310
311		/* Fill the uncovered part XXX way too much */
312	0	ScreenFill( p_cdg, 0, 0, CDG_SCREEN_WIDTH, CDG_SCREEN_HEIGHT, color );
313
314		/* Copy back */
315	0	for( unsigned y = 0; y < CDG_SCREEN_HEIGHT; y++ )
316	0	{
317	0	int dy = i_shiftv + y;
318	0	for( unsigned x = 0; x < CDG_SCREEN_WIDTH; x++ )
319	0	{
320	0	int dx = i_shifth + x;
321
322	0	if( b_copy )
323	0	{
324	0	dy = (dy + CDG_SCREEN_HEIGHT) % CDG_SCREEN_HEIGHT;
325	0	dx = (dx + CDG_SCREEN_WIDTH ) % CDG_SCREEN_WIDTH;
326	0	}
327	0	else
328	0	{
329	0	if( dy < 0 \|\| (unsigned)dy >= CDG_SCREEN_HEIGHT \|\|
330	0	dx < 0 \|\| (unsigned)dx >= CDG_SCREEN_WIDTH )
331	0	continue;
332	0	}
333	0	p_cdg->screen[dyCDG_SCREEN_PITCH+dx] = copy[yCDG_SCREEN_PITCH+x];
334	0	}
335	0	}
336		/* */
337		//CdgDebug( CDG_LOG_WARNING, "DecodeScroll: color=%d ch=%d oh=%d cv=%d ov=%d\n copy=%d\n", color, i_shifth, p_cdg->i_offseth, i_shiftv, p_cdg->i_offsetv, b_copy );
338	0	return 0;
339	0	}
340
341		static int DecodePacket( decoder_sys_t p_cdg, uint8_t p_buffer, int i_buffer )
342	0	{
343	0	const int i_cmd = p_buffer[0] & 0x3f;
344	0	const int i_instruction = p_buffer[1] & 0x3f;
345	0	const uint8_t *p_data = &p_buffer[4];
346
347	0	if( i_buffer != CDG_PACKET_SIZE )
348	0	return -1;
349
350	0	p_cdg->i_packet++;
351
352		/* Handle CDG command only */
353	0	if( i_cmd != 0x09 )
354	0	return 0;
355
356	0	switch( i_instruction )
357	0	{
358	0	case 1:
359	0	DecodeMemoryPreset( p_cdg, p_data );
360	0	break;
361	0	case 2:
362	0	DecodeBorderPreset( p_cdg, p_data );
363	0	break;
364	0	case 6:
365	0	DecodeTileBlock( p_cdg, p_data, 0 );
366	0	break;
367	0	case 20:
368	0	DecodeScroll( p_cdg, p_data, 0 );
369	0	break;
370	0	case 24:
371	0	DecodeScroll( p_cdg, p_data, 1 );
372	0	break;
373	0	case 28:
374		/* FIXME what to do about that one ? */
375		//CdgDebug( CDG_LOG_WARNING, "DecodeDefineTransparentColor not implemented\n" );
376		//DecodeDefineTransparentColor( p_cdg, p_data );
377	0	break;
378	0	case 30:
379	0	DecodeLoadColorTable( p_cdg, p_data, 0 );
380	0	break;
381	0	case 31:
382	0	DecodeLoadColorTable( p_cdg, p_data, 8 );
383	0	break;
384	0	case 38:
385	0	DecodeTileBlock( p_cdg, p_data, 1 );
386	0	break;
387	0	default:
388	0	break;
389	0	}
390	0	return 0;
391	0	}
392
393		static void RenderPixel( picture_t *p_picture, int x, int y, uint32_t c )
394	0	{
395	0	const int i_plane = 0;
396	0	const int i_pitch = p_picture->p[i_plane].i_pitch;
397	0	uint32_t s = (uint32_t)&p_picture->p[i_plane].p_pixels[yi_pitch + xsizeof(uint32_t)];
398	0	*s = c;
399	0	}
400		static uint32_t RenderRGB( int r, int g, int b )
401	0	{
402	0	return ( r << CDG_COLOR_R_SHIFT ) \| ( g << CDG_COLOR_G_SHIFT ) \| ( b << CDG_COLOR_B_SHIFT );
403	0	}
404
405		static int Render( decoder_sys_t p_cdg, picture_t p_picture )
406	0	{
407	0	for( unsigned y = 0; y < CDG_DISPLAY_HEIGHT; y++ )
408	0	{
409	0	for( unsigned x = 0; x < CDG_DISPLAY_WIDTH; x++ )
410	0	{
411	0	const int sx = x + p_cdg->i_offseth + CDG_SCREEN_BORDER_WIDTH;
412	0	const int sy = y + p_cdg->i_offsetv + CDG_SCREEN_BORDER_HEIGHT;
413	0	uint8_t cidx = p_cdg->p_screen[sy*CDG_SCREEN_PITCH +sx];
414	0	uint8_t r = p_cdg->color[cidx][0];
415	0	uint8_t g = p_cdg->color[cidx][1];
416	0	uint8_t b = p_cdg->color[cidx][2];
417
418	0	RenderPixel( p_picture, x, y, RenderRGB( r, g, b ) );
419	0	}
420	0	}
421	0	return 0;
422	0	}
423