libavcodec/bmp.c

   1 /*
   2  * BMP image format decoder
   3  * Copyright (c) 2005 Mans Rullgard
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "avcodec.h"
  23 #include "bytestream.h"
  24 #include "bmp.h"
  25 #include "msrledec.h"
  26
  27 static av_cold int bmp_decode_init(AVCodecContext *avctx){
  28     BMPContext *s = avctx->priv_data;
  29
  30     avcodec_get_frame_defaults((AVFrame*)&s->picture);
  31     avctx->coded_frame = (AVFrame*)&s->picture;
  32
  33     return 0;
  34 }
  35
  36 static int bmp_decode_frame(AVCodecContext *avctx,
  37                             void *data, int *data_size,
  38                             const uint8_t *buf, int buf_size)
  39 {
  40     BMPContext *s = avctx->priv_data;
  41     AVFrame *picture = data;
  42     AVFrame *p = &s->picture;
  43     unsigned int fsize, hsize;
  44     int width, height;
  45     unsigned int depth;
  46     BiCompression comp;
  47     unsigned int ihsize;
  48     int i, j, n, linesize;
  49     uint32_t rgb[3];
  50     uint8_t *ptr;
  51     int dsize;
  52     const uint8_t *buf0 = buf;
  53
  54     if(buf_size < 14){
  55         av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
  56         return -1;
  57     }
  58
  59     if(bytestream_get_byte(&buf) != 'B' ||
  60        bytestream_get_byte(&buf) != 'M') {
  61         av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
  62         return -1;
  63     }
  64
  65     fsize = bytestream_get_le32(&buf);
  66     if(buf_size < fsize){
  67         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d), trying to decode anyway\n",
  68                buf_size, fsize);
  69         fsize = buf_size;
  70     }
  71
  72     buf += 2; /* reserved1 */
  73     buf += 2; /* reserved2 */
  74
  75     hsize = bytestream_get_le32(&buf); /* header size */
  76     ihsize = bytestream_get_le32(&buf);       /* more header size */
  77     if(ihsize + 14 > hsize){
  78         av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
  79         return -1;
  80     }
  81
  82     /* sometimes file size is set to some headers size, set a real size in that case */
  83     if(fsize == 14 || fsize == ihsize + 14)
  84         fsize = buf_size - 2;
  85
  86     if(fsize <= hsize){
  87         av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n",
  88                fsize, hsize);
  89         return -1;
  90     }
  91
  92     switch(ihsize){
  93     case  40: // windib v3
  94     case  64: // OS/2 v2
  95     case 108: // windib v4
  96     case 124: // windib v5
  97         width = bytestream_get_le32(&buf);
  98         height = bytestream_get_le32(&buf);
  99         break;
 100     case  12: // OS/2 v1
 101         width  = bytestream_get_le16(&buf);
 102         height = bytestream_get_le16(&buf);
 103         break;
 104     default:
 105         av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n");
 106         return -1;
 107     }
 108
 109     if(bytestream_get_le16(&buf) != 1){ /* planes */
 110         av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
 111         return -1;
 112     }
 113
 114     depth = bytestream_get_le16(&buf);
 115
 116     if(ihsize == 40)
 117         comp = bytestream_get_le32(&buf);
 118     else
 119         comp = BMP_RGB;
 120
 121     if(comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 && comp != BMP_RLE8){
 122         av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
 123         return -1;
 124     }
 125
 126     if(comp == BMP_BITFIELDS){
 127         buf += 20;
 128         rgb[0] = bytestream_get_le32(&buf);
 129         rgb[1] = bytestream_get_le32(&buf);
 130         rgb[2] = bytestream_get_le32(&buf);
 131     }
 132
 133     avctx->width = width;
 134     avctx->height = height > 0? height: -height;
 135
 136     avctx->pix_fmt = PIX_FMT_NONE;
 137
 138     switch(depth){
 139     case 32:
 140         if(comp == BMP_BITFIELDS){
 141             rgb[0] = (rgb[0] >> 15) & 3;
 142             rgb[1] = (rgb[1] >> 15) & 3;
 143             rgb[2] = (rgb[2] >> 15) & 3;
 144
 145             if(rgb[0] + rgb[1] + rgb[2] != 3 ||
 146                rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){
 147                 break;
 148             }
 149         } else {
 150             rgb[0] = 2;
 151             rgb[1] = 1;
 152             rgb[2] = 0;
 153         }
 154
 155         avctx->pix_fmt = PIX_FMT_BGR24;
 156         break;
 157     case 24:
 158         avctx->pix_fmt = PIX_FMT_BGR24;
 159         break;
 160     case 16:
 161         if(comp == BMP_RGB)
 162             avctx->pix_fmt = PIX_FMT_RGB555;
 163         if(comp == BMP_BITFIELDS)
 164             avctx->pix_fmt = rgb[1] == 0x07E0 ? PIX_FMT_RGB565 : PIX_FMT_RGB555;
 165         break;
 166     case 8:
 167         if(hsize - ihsize - 14 > 0)
 168             avctx->pix_fmt = PIX_FMT_PAL8;
 169         else
 170             avctx->pix_fmt = PIX_FMT_GRAY8;
 171         break;
 172     case 4:
 173         if(hsize - ihsize - 14 > 0){
 174             avctx->pix_fmt = PIX_FMT_PAL8;
 175         }else{
 176             av_log(avctx, AV_LOG_ERROR, "Unknown palette for 16-colour BMP\n");
 177             return -1;
 178         }
 179         break;
 180     case 1:
 181         avctx->pix_fmt = PIX_FMT_MONOBLACK;
 182         break;
 183     default:
 184         av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
 185         return -1;
 186     }
 187
 188     if(avctx->pix_fmt == PIX_FMT_NONE){
 189         av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
 190         return -1;
 191     }
 192
 193     if(p->data[0])
 194         avctx->release_buffer(avctx, p);
 195
 196     p->reference = 0;
 197     if(avctx->get_buffer(avctx, p) < 0){
 198         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 199         return -1;
 200     }
 201     p->pict_type = FF_I_TYPE;
 202     p->key_frame = 1;
 203
 204     buf = buf0 + hsize;
 205     dsize = buf_size - hsize;
 206
 207     /* Line size in file multiple of 4 */
 208     n = ((avctx->width * depth) / 8 + 3) & ~3;
 209
 210     if(n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8){
 211         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
 212                dsize, n * avctx->height);
 213         return -1;
 214     }
 215
 216     // RLE may skip decoding some picture areas, so blank picture before decoding
 217     if(comp == BMP_RLE4 || comp == BMP_RLE8)
 218         memset(p->data[0], 0, avctx->height * p->linesize[0]);
 219
 220     if(depth == 4 || depth == 8)
 221         memset(p->data[1], 0, 1024);
 222
 223     if(height > 0){
 224         ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
 225         linesize = -p->linesize[0];
 226     } else {
 227         ptr = p->data[0];
 228         linesize = p->linesize[0];
 229     }
 230
 231     if(avctx->pix_fmt == PIX_FMT_PAL8){
 232         buf = buf0 + 14 + ihsize; //palette location
 233         if((hsize-ihsize-14)>>depth < 4){ // OS/2 bitmap, 3 bytes per palette entry
 234             for(i = 0; i < (1 << depth); i++)
 235                 ((uint32_t*)p->data[1])[i] = bytestream_get_le24(&buf);
 236         }else{
 237             for(i = 0; i < (1 << depth); i++)
 238                 ((uint32_t*)p->data[1])[i] = bytestream_get_le32(&buf);
 239         }
 240         buf = buf0 + hsize;
 241     }
 242     if(comp == BMP_RLE4 || comp == BMP_RLE8){
 243         ff_msrle_decode(avctx, (AVPicture*)p, depth, buf, dsize);
 244     }else{
 245         switch(depth){
 246         case 1:
 247             for(i = 0; i < avctx->height; i++){
 248                 memcpy(ptr, buf, n);
 249                 buf += n;
 250                 ptr += linesize;
 251             }
 252             break;
 253         case 4:
 254             for(i = 0; i < avctx->height; i++){
 255                 int j;
 256                 for(j = 0; j < n; j++){
 257                     ptr[j*2+0] = (buf[j] >> 4) & 0xF;
 258                     ptr[j*2+1] = buf[j] & 0xF;
 259                 }
 260                 buf += n;
 261                 ptr += linesize;
 262             }
 263             break;
 264         case 8:
 265             for(i = 0; i < avctx->height; i++){
 266                 memcpy(ptr, buf, avctx->width);
 267                 buf += n;
 268                 ptr += linesize;
 269             }
 270             break;
 271         case 24:
 272             for(i = 0; i < avctx->height; i++){
 273                 memcpy(ptr, buf, avctx->width*(depth>>3));
 274                 buf += n;
 275                 ptr += linesize;
 276             }
 277             break;
 278         case 16:
 279             for(i = 0; i < avctx->height; i++){
 280                 const uint16_t *src = (const uint16_t *) buf;
 281                 uint16_t *dst = (uint16_t *) ptr;
 282
 283                 for(j = 0; j < avctx->width; j++)
 284                     *dst++ = le2me_16(*src++);
 285
 286                 buf += n;
 287                 ptr += linesize;
 288             }
 289             break;
 290         case 32:
 291             for(i = 0; i < avctx->height; i++){
 292                 const uint8_t *src = buf;
 293                 uint8_t *dst = ptr;
 294
 295                 for(j = 0; j < avctx->width; j++){
 296                     dst[0] = src[rgb[2]];
 297                     dst[1] = src[rgb[1]];
 298                     dst[2] = src[rgb[0]];
 299                     dst += 3;
 300                     src += 4;
 301                 }
 302
 303                 buf += n;
 304                 ptr += linesize;
 305             }
 306             break;
 307         default:
 308             av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
 309             return -1;
 310         }
 311     }
 312
 313     *picture = s->picture;
 314     *data_size = sizeof(AVPicture);
 315
 316     return buf_size;
 317 }
 318
 319 static av_cold int bmp_decode_end(AVCodecContext *avctx)
 320 {
 321     BMPContext* c = avctx->priv_data;
 322
 323     if (c->picture.data[0])
 324         avctx->release_buffer(avctx, &c->picture);
 325
 326     return 0;
 327 }
 328
 329 AVCodec bmp_decoder = {
 330     "bmp",
 331     CODEC_TYPE_VIDEO,
 332     CODEC_ID_BMP,
 333     sizeof(BMPContext),
 334     bmp_decode_init,
 335     NULL,
 336     bmp_decode_end,
 337     bmp_decode_frame,
 338     .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
 339 };