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Rev | Author | Line No. | Line |
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4349 | Serge | 1 | /* |
2 | * CD Graphics Video Decoder |
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3 | * Copyright (c) 2009 Michael Tison |
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4 | * |
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5 | * This file is part of FFmpeg. |
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6 | * |
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7 | * FFmpeg is free software; you can redistribute it and/or |
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8 | * modify it under the terms of the GNU Lesser General Public |
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9 | * License as published by the Free Software Foundation; either |
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10 | * version 2.1 of the License, or (at your option) any later version. |
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11 | * |
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12 | * FFmpeg is distributed in the hope that it will be useful, |
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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15 | * Lesser General Public License for more details. |
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16 | * |
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17 | * You should have received a copy of the GNU Lesser General Public |
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18 | * License along with FFmpeg; if not, write to the Free Software |
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19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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20 | */ |
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21 | |||
22 | #include "avcodec.h" |
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23 | #include "bytestream.h" |
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24 | #include "internal.h" |
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25 | |||
26 | /** |
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27 | * @file |
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28 | * @brief CD Graphics Video Decoder |
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29 | * @author Michael Tison |
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30 | * @see http://wiki.multimedia.cx/index.php?title=CD_Graphics |
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31 | * @see http://www.ccs.neu.edu/home/bchafy/cdb/info/cdg |
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32 | */ |
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33 | |||
34 | /// default screen sizes |
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35 | #define CDG_FULL_WIDTH 300 |
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36 | #define CDG_FULL_HEIGHT 216 |
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37 | #define CDG_DISPLAY_WIDTH 294 |
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38 | #define CDG_DISPLAY_HEIGHT 204 |
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39 | #define CDG_BORDER_WIDTH 6 |
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40 | #define CDG_BORDER_HEIGHT 12 |
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41 | |||
42 | /// masks |
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43 | #define CDG_COMMAND 0x09 |
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44 | #define CDG_MASK 0x3F |
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45 | |||
46 | /// instruction codes |
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47 | #define CDG_INST_MEMORY_PRESET 1 |
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48 | #define CDG_INST_BORDER_PRESET 2 |
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49 | #define CDG_INST_TILE_BLOCK 6 |
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50 | #define CDG_INST_SCROLL_PRESET 20 |
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51 | #define CDG_INST_SCROLL_COPY 24 |
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52 | #define CDG_INST_LOAD_PAL_LO 30 |
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53 | #define CDG_INST_LOAD_PAL_HIGH 31 |
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54 | #define CDG_INST_TILE_BLOCK_XOR 38 |
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55 | |||
56 | /// data sizes |
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57 | #define CDG_PACKET_SIZE 24 |
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58 | #define CDG_DATA_SIZE 16 |
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59 | #define CDG_TILE_HEIGHT 12 |
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60 | #define CDG_TILE_WIDTH 6 |
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61 | #define CDG_MINIMUM_PKT_SIZE 6 |
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62 | #define CDG_MINIMUM_SCROLL_SIZE 3 |
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63 | #define CDG_HEADER_SIZE 8 |
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64 | #define CDG_PALETTE_SIZE 16 |
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65 | |||
66 | typedef struct CDGraphicsContext { |
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67 | AVFrame *frame; |
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68 | int hscroll; |
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69 | int vscroll; |
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70 | } CDGraphicsContext; |
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71 | |||
72 | static av_cold int cdg_decode_init(AVCodecContext *avctx) |
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73 | { |
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74 | CDGraphicsContext *cc = avctx->priv_data; |
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75 | |||
76 | cc->frame = av_frame_alloc(); |
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77 | if (!cc->frame) |
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78 | return AVERROR(ENOMEM); |
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79 | |||
80 | avctx->width = CDG_FULL_WIDTH; |
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81 | avctx->height = CDG_FULL_HEIGHT; |
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82 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
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83 | |||
84 | return 0; |
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85 | } |
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86 | |||
87 | static void cdg_border_preset(CDGraphicsContext *cc, uint8_t *data) |
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88 | { |
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89 | int y; |
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90 | int lsize = cc->frame->linesize[0]; |
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91 | uint8_t *buf = cc->frame->data[0]; |
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92 | int color = data[0] & 0x0F; |
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93 | |||
94 | if (!(data[1] & 0x0F)) { |
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95 | /// fill the top and bottom borders |
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96 | memset(buf, color, CDG_BORDER_HEIGHT * lsize); |
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97 | memset(buf + (CDG_FULL_HEIGHT - CDG_BORDER_HEIGHT) * lsize, |
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98 | color, CDG_BORDER_HEIGHT * lsize); |
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99 | |||
100 | /// fill the side borders |
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101 | for (y = CDG_BORDER_HEIGHT; y < CDG_FULL_HEIGHT - CDG_BORDER_HEIGHT; y++) { |
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102 | memset(buf + y * lsize, color, CDG_BORDER_WIDTH); |
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103 | memset(buf + CDG_FULL_WIDTH - CDG_BORDER_WIDTH + y * lsize, |
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104 | color, CDG_BORDER_WIDTH); |
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105 | } |
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106 | } |
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107 | } |
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108 | |||
109 | static void cdg_load_palette(CDGraphicsContext *cc, uint8_t *data, int low) |
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110 | { |
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111 | uint8_t r, g, b; |
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112 | uint16_t color; |
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113 | int i; |
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114 | int array_offset = low ? 0 : 8; |
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115 | uint32_t *palette = (uint32_t *) cc->frame->data[1]; |
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116 | |||
117 | for (i = 0; i < 8; i++) { |
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118 | color = (data[2 * i] << 6) + (data[2 * i + 1] & 0x3F); |
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119 | r = ((color >> 8) & 0x000F) * 17; |
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120 | g = ((color >> 4) & 0x000F) * 17; |
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121 | b = ((color ) & 0x000F) * 17; |
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122 | palette[i + array_offset] = 0xFFU << 24 | r << 16 | g << 8 | b; |
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123 | } |
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124 | cc->frame->palette_has_changed = 1; |
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125 | } |
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126 | |||
127 | static int cdg_tile_block(CDGraphicsContext *cc, uint8_t *data, int b) |
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128 | { |
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129 | unsigned ci, ri; |
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130 | int color; |
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131 | int x, y; |
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132 | int ai; |
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133 | int stride = cc->frame->linesize[0]; |
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134 | uint8_t *buf = cc->frame->data[0]; |
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135 | |||
136 | ri = (data[2] & 0x1F) * CDG_TILE_HEIGHT + cc->vscroll; |
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137 | ci = (data[3] & 0x3F) * CDG_TILE_WIDTH + cc->hscroll; |
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138 | |||
139 | if (ri > (CDG_FULL_HEIGHT - CDG_TILE_HEIGHT)) |
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140 | return AVERROR(EINVAL); |
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141 | if (ci > (CDG_FULL_WIDTH - CDG_TILE_WIDTH)) |
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142 | return AVERROR(EINVAL); |
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143 | |||
144 | for (y = 0; y < CDG_TILE_HEIGHT; y++) { |
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145 | for (x = 0; x < CDG_TILE_WIDTH; x++) { |
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146 | if (!((data[4 + y] >> (5 - x)) & 0x01)) |
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147 | color = data[0] & 0x0F; |
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148 | else |
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149 | color = data[1] & 0x0F; |
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150 | |||
151 | ai = ci + x + (stride * (ri + y)); |
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152 | if (b) |
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153 | color ^= buf[ai]; |
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154 | buf[ai] = color; |
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155 | } |
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156 | } |
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157 | |||
158 | return 0; |
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159 | } |
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160 | |||
161 | #define UP 2 |
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162 | #define DOWN 1 |
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163 | #define LEFT 2 |
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164 | #define RIGHT 1 |
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165 | |||
166 | static void cdg_copy_rect_buf(int out_tl_x, int out_tl_y, uint8_t *out, |
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167 | int in_tl_x, int in_tl_y, uint8_t *in, |
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168 | int w, int h, int stride) |
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169 | { |
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170 | int y; |
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171 | |||
172 | in += in_tl_x + in_tl_y * stride; |
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173 | out += out_tl_x + out_tl_y * stride; |
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174 | for (y = 0; y < h; y++) |
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175 | memcpy(out + y * stride, in + y * stride, w); |
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176 | } |
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177 | |||
178 | static void cdg_fill_rect_preset(int tl_x, int tl_y, uint8_t *out, |
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179 | int color, int w, int h, int stride) |
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180 | { |
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181 | int y; |
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182 | |||
183 | for (y = tl_y; y < tl_y + h; y++) |
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184 | memset(out + tl_x + y * stride, color, w); |
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185 | } |
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186 | |||
187 | static void cdg_fill_wrapper(int out_tl_x, int out_tl_y, uint8_t *out, |
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188 | int in_tl_x, int in_tl_y, uint8_t *in, |
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189 | int color, int w, int h, int stride, int roll) |
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190 | { |
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191 | if (roll) { |
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192 | cdg_copy_rect_buf(out_tl_x, out_tl_y, out, in_tl_x, in_tl_y, |
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193 | in, w, h, stride); |
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194 | } else { |
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195 | cdg_fill_rect_preset(out_tl_x, out_tl_y, out, color, w, h, stride); |
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196 | } |
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197 | } |
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198 | |||
199 | static void cdg_scroll(CDGraphicsContext *cc, uint8_t *data, |
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200 | AVFrame *new_frame, int roll_over) |
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201 | { |
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202 | int color; |
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203 | int hscmd, h_off, hinc, vscmd, v_off, vinc; |
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204 | int y; |
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205 | int stride = cc->frame->linesize[0]; |
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206 | uint8_t *in = cc->frame->data[0]; |
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207 | uint8_t *out = new_frame->data[0]; |
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208 | |||
209 | color = data[0] & 0x0F; |
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210 | hscmd = (data[1] & 0x30) >> 4; |
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211 | vscmd = (data[2] & 0x30) >> 4; |
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212 | |||
213 | h_off = FFMIN(data[1] & 0x07, CDG_BORDER_WIDTH - 1); |
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214 | v_off = FFMIN(data[2] & 0x0F, CDG_BORDER_HEIGHT - 1); |
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215 | |||
216 | /// find the difference and save the offset for cdg_tile_block usage |
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217 | hinc = h_off - cc->hscroll; |
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218 | vinc = v_off - cc->vscroll; |
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219 | cc->hscroll = h_off; |
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220 | cc->vscroll = v_off; |
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221 | |||
222 | if (vscmd == UP) |
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223 | vinc -= 12; |
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224 | if (vscmd == DOWN) |
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225 | vinc += 12; |
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226 | if (hscmd == LEFT) |
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227 | hinc -= 6; |
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228 | if (hscmd == RIGHT) |
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229 | hinc += 6; |
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230 | |||
231 | if (!hinc && !vinc) |
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232 | return; |
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233 | |||
234 | memcpy(new_frame->data[1], cc->frame->data[1], CDG_PALETTE_SIZE * 4); |
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235 | |||
236 | for (y = FFMAX(0, vinc); y < FFMIN(CDG_FULL_HEIGHT + vinc, CDG_FULL_HEIGHT); y++) |
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237 | memcpy(out + FFMAX(0, hinc) + stride * y, |
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238 | in + FFMAX(0, hinc) - hinc + (y - vinc) * stride, |
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239 | FFMIN(stride + hinc, stride)); |
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240 | |||
241 | if (vinc > 0) |
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242 | cdg_fill_wrapper(0, 0, out, |
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243 | 0, CDG_FULL_HEIGHT - vinc, in, color, |
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244 | stride, vinc, stride, roll_over); |
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245 | else if (vinc < 0) |
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246 | cdg_fill_wrapper(0, CDG_FULL_HEIGHT + vinc, out, |
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247 | 0, 0, in, color, |
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248 | stride, -1 * vinc, stride, roll_over); |
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249 | |||
250 | if (hinc > 0) |
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251 | cdg_fill_wrapper(0, 0, out, |
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252 | CDG_FULL_WIDTH - hinc, 0, in, color, |
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253 | hinc, CDG_FULL_HEIGHT, stride, roll_over); |
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254 | else if (hinc < 0) |
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255 | cdg_fill_wrapper(CDG_FULL_WIDTH + hinc, 0, out, |
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256 | 0, 0, in, color, |
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257 | -1 * hinc, CDG_FULL_HEIGHT, stride, roll_over); |
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258 | |||
259 | } |
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260 | |||
261 | static int cdg_decode_frame(AVCodecContext *avctx, |
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262 | void *data, int *got_frame, AVPacket *avpkt) |
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263 | { |
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264 | const uint8_t *buf = avpkt->data; |
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265 | int buf_size = avpkt->size; |
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266 | int ret; |
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267 | uint8_t command, inst; |
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268 | uint8_t cdg_data[CDG_DATA_SIZE] = {0}; |
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269 | AVFrame *frame = data; |
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270 | CDGraphicsContext *cc = avctx->priv_data; |
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271 | |||
272 | if (buf_size < CDG_MINIMUM_PKT_SIZE) { |
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273 | av_log(avctx, AV_LOG_ERROR, "buffer too small for decoder\n"); |
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274 | return AVERROR(EINVAL); |
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275 | } |
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276 | if (buf_size > CDG_HEADER_SIZE + CDG_DATA_SIZE) { |
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277 | av_log(avctx, AV_LOG_ERROR, "buffer too big for decoder\n"); |
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278 | return AVERROR(EINVAL); |
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279 | } |
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280 | |||
281 | if ((ret = ff_reget_buffer(avctx, cc->frame)) < 0) |
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282 | return ret; |
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283 | if (!avctx->frame_number) { |
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284 | memset(cc->frame->data[0], 0, cc->frame->linesize[0] * avctx->height); |
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285 | memset(cc->frame->data[1], 0, AVPALETTE_SIZE); |
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286 | } |
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287 | |||
288 | command = bytestream_get_byte(&buf); |
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289 | inst = bytestream_get_byte(&buf); |
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290 | inst &= CDG_MASK; |
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291 | buf += 2; /// skipping 2 unneeded bytes |
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292 | |||
293 | if (buf_size > CDG_HEADER_SIZE) |
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294 | bytestream_get_buffer(&buf, cdg_data, buf_size - CDG_HEADER_SIZE); |
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295 | |||
296 | if ((command & CDG_MASK) == CDG_COMMAND) { |
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297 | switch (inst) { |
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298 | case CDG_INST_MEMORY_PRESET: |
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299 | if (!(cdg_data[1] & 0x0F)) |
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300 | memset(cc->frame->data[0], cdg_data[0] & 0x0F, |
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301 | cc->frame->linesize[0] * CDG_FULL_HEIGHT); |
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302 | break; |
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303 | case CDG_INST_LOAD_PAL_LO: |
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304 | case CDG_INST_LOAD_PAL_HIGH: |
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305 | if (buf_size - CDG_HEADER_SIZE < CDG_DATA_SIZE) { |
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306 | av_log(avctx, AV_LOG_ERROR, "buffer too small for loading palette\n"); |
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307 | return AVERROR(EINVAL); |
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308 | } |
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309 | |||
310 | cdg_load_palette(cc, cdg_data, inst == CDG_INST_LOAD_PAL_LO); |
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311 | break; |
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312 | case CDG_INST_BORDER_PRESET: |
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313 | cdg_border_preset(cc, cdg_data); |
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314 | break; |
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315 | case CDG_INST_TILE_BLOCK_XOR: |
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316 | case CDG_INST_TILE_BLOCK: |
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317 | if (buf_size - CDG_HEADER_SIZE < CDG_DATA_SIZE) { |
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318 | av_log(avctx, AV_LOG_ERROR, "buffer too small for drawing tile\n"); |
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319 | return AVERROR(EINVAL); |
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320 | } |
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321 | |||
322 | ret = cdg_tile_block(cc, cdg_data, inst == CDG_INST_TILE_BLOCK_XOR); |
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323 | if (ret) { |
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324 | av_log(avctx, AV_LOG_ERROR, "tile is out of range\n"); |
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325 | return ret; |
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326 | } |
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327 | break; |
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328 | case CDG_INST_SCROLL_PRESET: |
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329 | case CDG_INST_SCROLL_COPY: |
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330 | if (buf_size - CDG_HEADER_SIZE < CDG_MINIMUM_SCROLL_SIZE) { |
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331 | av_log(avctx, AV_LOG_ERROR, "buffer too small for scrolling\n"); |
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332 | return AVERROR(EINVAL); |
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333 | } |
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334 | |||
335 | if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0) |
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336 | return ret; |
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337 | |||
338 | cdg_scroll(cc, cdg_data, frame, inst == CDG_INST_SCROLL_COPY); |
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339 | av_frame_unref(cc->frame); |
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340 | ret = av_frame_ref(cc->frame, frame); |
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341 | if (ret < 0) |
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342 | return ret; |
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343 | break; |
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344 | default: |
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345 | break; |
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346 | } |
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347 | |||
348 | if (!frame->data[0]) { |
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349 | ret = av_frame_ref(frame, cc->frame); |
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350 | if (ret < 0) |
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351 | return ret; |
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352 | } |
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353 | *got_frame = 1; |
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354 | } else { |
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355 | *got_frame = 0; |
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356 | buf_size = 0; |
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357 | } |
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358 | |||
359 | return buf_size; |
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360 | } |
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361 | |||
362 | static av_cold int cdg_decode_end(AVCodecContext *avctx) |
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363 | { |
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364 | CDGraphicsContext *cc = avctx->priv_data; |
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365 | |||
366 | av_frame_free(&cc->frame); |
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367 | |||
368 | return 0; |
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369 | } |
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370 | |||
371 | AVCodec ff_cdgraphics_decoder = { |
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372 | .name = "cdgraphics", |
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373 | .long_name = NULL_IF_CONFIG_SMALL("CD Graphics video"), |
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374 | .type = AVMEDIA_TYPE_VIDEO, |
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375 | .id = AV_CODEC_ID_CDGRAPHICS, |
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376 | .priv_data_size = sizeof(CDGraphicsContext), |
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377 | .init = cdg_decode_init, |
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378 | .close = cdg_decode_end, |
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379 | .decode = cdg_decode_frame, |
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380 | .capabilities = CODEC_CAP_DR1, |
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381 | };>>>>>>>>>>>>>>>><>><>><>><>>> |