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                             AVPacket *avpkt)
  39 {
  40     const uint8_t *buf = avpkt->data;
  41     int buf_size = avpkt->size;
  42     BMPContext *s = avctx->priv_data;
  43     AVFrame *picture = data;
  44     AVFrame *p = &s->picture;
  45     unsigned int fsize, hsize;
  46     int width, height;
  47     unsigned int depth;
  48     BiCompression comp;
  49     unsigned int ihsize;
  50     int i, j, n, linesize;
  51     uint32_t rgb[3];
  52     uint8_t *ptr;
  53     int dsize;
  54     const uint8_t *buf0 = buf;
  55
  56     if(buf_size < 14){
  57         av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
  58         return -1;
  59     }
  60
  61     if(bytestream_get_byte(&buf) != 'B' ||
  62        bytestream_get_byte(&buf) != 'M') {
  63         av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
  64         return -1;
  65     }
  66
  67     fsize = bytestream_get_le32(&buf);
  68     if(buf_size < fsize){
  69         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d), trying to decode anyway\n",
  70                buf_size, fsize);
  71         fsize = buf_size;
  72     }
  73
  74     buf += 2; /* reserved1 */
  75     buf += 2; /* reserved2 */
  76
  77     hsize = bytestream_get_le32(&buf); /* header size */
  78     ihsize = bytestream_get_le32(&buf);       /* more header size */
  79     if(ihsize + 14 > hsize){
  80         av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
  81         return -1;
  82     }
  83
  84     /* sometimes file size is set to some headers size, set a real size in that case */
  85     if(fsize == 14 || fsize == ihsize + 14)
  86         fsize = buf_size - 2;
  87
  88     if(fsize <= hsize){
  89         av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n",
  90                fsize, hsize);
  91         return -1;
  92     }
  93
  94     switch(ihsize){
  95     case  40: // windib v3
  96     case  64: // OS/2 v2
  97     case 108: // windib v4
  98     case 124: // windib v5
  99         width = bytestream_get_le32(&buf);
 100         height = bytestream_get_le32(&buf);
 101         break;
 102     case  12: // OS/2 v1
 103         width  = bytestream_get_le16(&buf);
 104         height = bytestream_get_le16(&buf);
 105         break;
 106     default:
 107         av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n");
 108         return -1;
 109     }
 110
 111     if(bytestream_get_le16(&buf) != 1){ /* planes */
 112         av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
 113         return -1;
 114     }
 115
 116     depth = bytestream_get_le16(&buf);
 117
 118     if(ihsize == 40)
 119         comp = bytestream_get_le32(&buf);
 120     else
 121         comp = BMP_RGB;
 122
 123     if(comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 && comp != BMP_RLE8){
 124         av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
 125         return -1;
 126     }
 127
 128     if(comp == BMP_BITFIELDS){
 129         buf += 20;
 130         rgb[0] = bytestream_get_le32(&buf);
 131         rgb[1] = bytestream_get_le32(&buf);
 132         rgb[2] = bytestream_get_le32(&buf);
 133     }
 134
 135     avctx->width = width;
 136     avctx->height = height > 0? height: -height;
 137
 138     avctx->pix_fmt = PIX_FMT_NONE;
 139
 140     switch(depth){
 141     case 32:
 142         if(comp == BMP_BITFIELDS){
 143             rgb[0] = (rgb[0] >> 15) & 3;
 144             rgb[1] = (rgb[1] >> 15) & 3;
 145             rgb[2] = (rgb[2] >> 15) & 3;
 146
 147             if(rgb[0] + rgb[1] + rgb[2] != 3 ||
 148                rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){
 149                 break;
 150             }
 151         } else {
 152             rgb[0] = 2;
 153             rgb[1] = 1;
 154             rgb[2] = 0;
 155         }
 156
 157         avctx->pix_fmt = PIX_FMT_BGR24;
 158         break;
 159     case 24:
 160         avctx->pix_fmt = PIX_FMT_BGR24;
 161         break;
 162     case 16:
 163         if(comp == BMP_RGB)
 164             avctx->pix_fmt = PIX_FMT_RGB555;
 165         if(comp == BMP_BITFIELDS)
 166             avctx->pix_fmt = rgb[1] == 0x07E0 ? PIX_FMT_RGB565 : PIX_FMT_RGB555;
 167         break;
 168     case 8:
 169         if(hsize - ihsize - 14 > 0)
 170             avctx->pix_fmt = PIX_FMT_PAL8;
 171         else
 172             avctx->pix_fmt = PIX_FMT_GRAY8;
 173         break;
 174     case 4:
 175         if(hsize - ihsize - 14 > 0){
 176             avctx->pix_fmt = PIX_FMT_PAL8;
 177         }else{
 178             av_log(avctx, AV_LOG_ERROR, "Unknown palette for 16-colour BMP\n");
 179             return -1;
 180         }
 181         break;
 182     case 1:
 183         avctx->pix_fmt = PIX_FMT_MONOBLACK;
 184         break;
 185     default:
 186         av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
 187         return -1;
 188     }
 189
 190     if(avctx->pix_fmt == PIX_FMT_NONE){
 191         av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
 192         return -1;
 193     }
 194
 195     if(p->data[0])
 196         avctx->release_buffer(avctx, p);
 197
 198     p->reference = 0;
 199     if(avctx->get_buffer(avctx, p) < 0){
 200         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 201         return -1;
 202     }
 203     p->pict_type = FF_I_TYPE;
 204     p->key_frame = 1;
 205
 206     buf = buf0 + hsize;
 207     dsize = buf_size - hsize;
 208
 209     /* Line size in file multiple of 4 */
 210     n = ((avctx->width * depth) / 8 + 3) & ~3;
 211
 212     if(n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8){
 213         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
 214                dsize, n * avctx->height);
 215         return -1;
 216     }
 217
 218     // RLE may skip decoding some picture areas, so blank picture before decoding
 219     if(comp == BMP_RLE4 || comp == BMP_RLE8)
 220         memset(p->data[0], 0, avctx->height * p->linesize[0]);
 221
 222     if(depth == 4 || depth == 8)
 223         memset(p->data[1], 0, 1024);
 224
 225     if(height > 0){
 226         ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
 227         linesize = -p->linesize[0];
 228     } else {
 229         ptr = p->data[0];
 230         linesize = p->linesize[0];
 231     }
 232
 233     if(avctx->pix_fmt == PIX_FMT_PAL8){
 234         int colors = 1 << depth;
 235         if(ihsize >= 36){
 236             int t;
 237             buf = buf0 + 46;
 238             t = bytestream_get_le32(&buf);
 239             if(t < 0 || t > (1 << depth)){
 240                 av_log(avctx, AV_LOG_ERROR, "Incorrect number of colors - %X for bitdepth %d\n", t, depth);
 241             }else if(t){
 242                 colors = t;
 243             }
 244         }
 245         buf = buf0 + 14 + ihsize; //palette location
 246         if((hsize-ihsize-14) < (colors << 2)){ // OS/2 bitmap, 3 bytes per palette entry
 247             for(i = 0; i < colors; i++)
 248                 ((uint32_t*)p->data[1])[i] = bytestream_get_le24(&buf);
 249         }else{
 250             for(i = 0; i < colors; i++)
 251                 ((uint32_t*)p->data[1])[i] = bytestream_get_le32(&buf);
 252         }
 253         buf = buf0 + hsize;
 254     }
 255     if(comp == BMP_RLE4 || comp == BMP_RLE8){
 256         if(height < 0){
 257             p->data[0] += p->linesize[0] * (avctx->height - 1);
 258             p->linesize[0] = -p->linesize[0];
 259         }
 260         ff_msrle_decode(avctx, (AVPicture*)p, depth, buf, dsize);
 261         if(height < 0){
 262             p->data[0] += p->linesize[0] * (avctx->height - 1);
 263             p->linesize[0] = -p->linesize[0];
 264         }
 265     }else{
 266         switch(depth){
 267         case 1:
 268         case 8:
 269         case 24:
 270             for(i = 0; i < avctx->height; i++){
 271                 memcpy(ptr, buf, n);
 272                 buf += n;
 273                 ptr += linesize;
 274             }
 275             break;
 276         case 4:
 277             for(i = 0; i < avctx->height; i++){
 278                 int j;
 279                 for(j = 0; j < n; j++){
 280                     ptr[j*2+0] = (buf[j] >> 4) & 0xF;
 281                     ptr[j*2+1] = buf[j] & 0xF;
 282                 }
 283                 buf += n;
 284                 ptr += linesize;
 285             }
 286             break;
 287         case 16:
 288             for(i = 0; i < avctx->height; i++){
 289                 const uint16_t *src = (const uint16_t *) buf;
 290                 uint16_t *dst = (uint16_t *) ptr;
 291
 292                 for(j = 0; j < avctx->width; j++)
 293                     *dst++ = le2me_16(*src++);
 294
 295                 buf += n;
 296                 ptr += linesize;
 297             }
 298             break;
 299         case 32:
 300             for(i = 0; i < avctx->height; i++){
 301                 const uint8_t *src = buf;
 302                 uint8_t *dst = ptr;
 303
 304                 for(j = 0; j < avctx->width; j++){
 305                     dst[0] = src[rgb[2]];
 306                     dst[1] = src[rgb[1]];
 307                     dst[2] = src[rgb[0]];
 308                     dst += 3;
 309                     src += 4;
 310                 }
 311
 312                 buf += n;
 313                 ptr += linesize;
 314             }
 315             break;
 316         default:
 317             av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
 318             return -1;
 319         }
 320     }
 321
 322     *picture = s->picture;
 323     *data_size = sizeof(AVPicture);
 324
 325     return buf_size;
 326 }
 327
 328 static av_cold int bmp_decode_end(AVCodecContext *avctx)
 329 {
 330     BMPContext* c = avctx->priv_data;
 331
 332     if (c->picture.data[0])
 333         avctx->release_buffer(avctx, &c->picture);
 334
 335     return 0;
 336 }
 337
 338 AVCodec bmp_decoder = {
 339     "bmp",
 340     CODEC_TYPE_VIDEO,
 341     CODEC_ID_BMP,
 342     sizeof(BMPContext),
 343     bmp_decode_init,
 344     NULL,
 345     bmp_decode_end,
 346     bmp_decode_frame,
 347     CODEC_CAP_DR1,
 348     .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
 349 };