ffmpeg / libavcodec / bmp.c @ 94d85eaf
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1 | 9fa62f2a | Måns Rullgård | /*
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2 | * BMP image format
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3 | * Copyright (c) 2005 Mans Rullgard
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4 | *
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5 | * This library is free software; you can redistribute it and/or
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6 | * modify it under the terms of the GNU Lesser General Public
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7 | * License as published by the Free Software Foundation; either
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8 | * version 2 of the License, or (at your option) any later version.
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9 | *
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10 | * This library is distributed in the hope that it will be useful,
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11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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13 | * Lesser General Public License for more details.
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14 | *
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15 | * You should have received a copy of the GNU Lesser General Public
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16 | * License along with this library; if not, write to the Free Software
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17 | 5509bffa | Diego Biurrun | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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18 | 9fa62f2a | Måns Rullgård | */
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19 | |||
20 | #include "avcodec.h" |
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21 | #include "bitstream.h" |
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22 | #include "bswap.h" |
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23 | |||
24 | typedef struct BMPContext { |
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25 | AVFrame picture; |
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26 | } BMPContext; |
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27 | |||
28 | #define BMP_RGB 0 |
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29 | #define BMP_RLE8 1 |
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30 | #define BMP_RLE4 2 |
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31 | #define BMP_BITFIELDS 3 |
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32 | |||
33 | #define read16(bits) bswap_16(get_bits(bits, 16)) |
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34 | #define read32(bits) bswap_32(get_bits_long(bits, 32)) |
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35 | |||
36 | static int bmp_decode_init(AVCodecContext *avctx){ |
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37 | BMPContext *s = avctx->priv_data; |
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38 | |||
39 | avcodec_get_frame_defaults((AVFrame*)&s->picture); |
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40 | avctx->coded_frame = (AVFrame*)&s->picture; |
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41 | |||
42 | return 0; |
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43 | } |
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44 | |||
45 | 115329f1 | Diego Biurrun | static int bmp_decode_frame(AVCodecContext *avctx, |
46 | 9fa62f2a | Måns Rullgård | void *data, int *data_size, |
47 | uint8_t *buf, int buf_size)
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48 | { |
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49 | BMPContext *s = avctx->priv_data; |
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50 | AVFrame *picture = data; |
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51 | AVFrame *p = &s->picture; |
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52 | GetBitContext bits; |
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53 | unsigned int fsize, hsize; |
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54 | int width, height;
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55 | unsigned int depth; |
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56 | unsigned int comp; |
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57 | unsigned int ihsize; |
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58 | int i, j, n, linesize;
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59 | uint32_t rgb[3];
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60 | uint8_t *ptr; |
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61 | int dsize;
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62 | |||
63 | if(buf_size < 14){ |
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64 | av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
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65 | return -1; |
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66 | } |
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67 | |||
68 | init_get_bits(&bits, buf, buf_size); |
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69 | |||
70 | if(get_bits(&bits, 16) != 0x424d){ /* 'BM' */ |
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71 | av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
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72 | return -1; |
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73 | } |
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74 | |||
75 | fsize = read32(&bits); |
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76 | if(buf_size < fsize){
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77 | av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
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78 | buf_size, fsize); |
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79 | return -1; |
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80 | } |
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81 | |||
82 | skip_bits(&bits, 16); /* reserved1 */ |
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83 | skip_bits(&bits, 16); /* reserved2 */ |
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84 | |||
85 | hsize = read32(&bits); /* header size */
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86 | if(fsize <= hsize){
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87 | av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
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88 | fsize, hsize); |
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89 | return -1; |
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90 | } |
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91 | |||
92 | ihsize = read32(&bits); /* more header size */
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93 | if(ihsize + 14 > hsize){ |
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94 | av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
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95 | return -1; |
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96 | } |
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97 | |||
98 | width = read32(&bits); |
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99 | height = read32(&bits); |
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100 | |||
101 | if(read16(&bits) != 1){ /* planes */ |
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102 | av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
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103 | return -1; |
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104 | } |
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105 | |||
106 | depth = read16(&bits); |
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107 | |||
108 | if(ihsize > 16) |
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109 | comp = read32(&bits); |
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110 | else
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111 | comp = BMP_RGB; |
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112 | |||
113 | if(comp != BMP_RGB && comp != BMP_BITFIELDS){
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114 | av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
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115 | return -1; |
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116 | } |
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117 | |||
118 | if(comp == BMP_BITFIELDS){
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119 | skip_bits(&bits, 20 * 8); |
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120 | rgb[0] = read32(&bits);
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121 | rgb[1] = read32(&bits);
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122 | rgb[2] = read32(&bits);
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123 | } |
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124 | |||
125 | avctx->codec_id = CODEC_ID_BMP; |
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126 | avctx->width = width; |
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127 | avctx->height = height > 0? height: -height;
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128 | |||
129 | avctx->pix_fmt = PIX_FMT_NONE; |
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130 | |||
131 | switch(depth){
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132 | case 32: |
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133 | if(comp == BMP_BITFIELDS){
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134 | rgb[0] = (rgb[0] >> 15) & 3; |
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135 | rgb[1] = (rgb[1] >> 15) & 3; |
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136 | rgb[2] = (rgb[2] >> 15) & 3; |
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137 | |||
138 | if(rgb[0] + rgb[1] + rgb[2] != 3 || |
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139 | rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){ |
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140 | break;
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141 | } |
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142 | } else {
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143 | rgb[0] = 2; |
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144 | rgb[1] = 1; |
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145 | rgb[2] = 0; |
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146 | } |
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147 | |||
148 | avctx->pix_fmt = PIX_FMT_BGR24; |
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149 | break;
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150 | case 24: |
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151 | avctx->pix_fmt = PIX_FMT_BGR24; |
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152 | break;
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153 | case 16: |
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154 | if(comp == BMP_RGB)
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155 | avctx->pix_fmt = PIX_FMT_RGB555; |
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156 | break;
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157 | default:
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158 | av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
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159 | return -1; |
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160 | } |
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161 | |||
162 | if(avctx->pix_fmt == PIX_FMT_NONE){
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163 | av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
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164 | return -1; |
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165 | } |
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166 | |||
167 | p->reference = 0;
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168 | if(avctx->get_buffer(avctx, p) < 0){ |
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169 | av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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170 | return -1; |
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171 | } |
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172 | p->pict_type = FF_I_TYPE; |
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173 | p->key_frame = 1;
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174 | |||
175 | buf += hsize; |
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176 | dsize = buf_size - hsize; |
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177 | |||
178 | n = avctx->width * (depth / 8);
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179 | |||
180 | if(n * avctx->height > dsize){
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181 | av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
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182 | dsize, n * avctx->height); |
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183 | return -1; |
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184 | } |
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185 | |||
186 | if(height > 0){ |
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187 | ptr = p->data[0] + (avctx->height - 1) * p->linesize[0]; |
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188 | linesize = -p->linesize[0];
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189 | } else {
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190 | ptr = p->data[0];
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191 | linesize = p->linesize[0];
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192 | } |
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193 | |||
194 | switch(depth){
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195 | case 24: |
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196 | for(i = 0; i < avctx->height; i++){ |
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197 | memcpy(ptr, buf, n); |
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198 | buf += n; |
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199 | ptr += linesize; |
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200 | } |
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201 | break;
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202 | case 16: |
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203 | for(i = 0; i < avctx->height; i++){ |
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204 | uint16_t *src = (uint16_t *) buf; |
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205 | uint16_t *dst = (uint16_t *) ptr; |
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206 | |||
207 | for(j = 0; j < avctx->width; j++) |
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208 | *dst++ = le2me_16(*src++); |
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209 | |||
210 | buf += n; |
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211 | ptr += linesize; |
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212 | } |
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213 | break;
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214 | case 32: |
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215 | for(i = 0; i < avctx->height; i++){ |
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216 | uint8_t *src = buf; |
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217 | uint8_t *dst = ptr; |
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218 | |||
219 | for(j = 0; j < avctx->width; j++){ |
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220 | dst[0] = src[rgb[2]]; |
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221 | dst[1] = src[rgb[1]]; |
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222 | dst[2] = src[rgb[0]]; |
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223 | dst += 3;
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224 | src += 4;
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225 | } |
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226 | |||
227 | buf += n; |
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228 | ptr += linesize; |
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229 | } |
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230 | break;
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231 | default:
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232 | av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
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233 | return -1; |
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234 | } |
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235 | |||
236 | *picture = s->picture; |
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237 | *data_size = sizeof(AVPicture);
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238 | |||
239 | return buf_size;
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240 | } |
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241 | |||
242 | AVCodec bmp_decoder = { |
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243 | "bmp",
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244 | CODEC_TYPE_VIDEO, |
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245 | CODEC_ID_BMP, |
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246 | sizeof(BMPContext),
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247 | bmp_decode_init, |
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248 | NULL,
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249 | NULL,
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250 | bmp_decode_frame |
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251 | }; |