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
  26 static av_cold int bmp_decode_init(AVCodecContext *avctx){
  27     BMPContext *s = avctx->priv_data;
  28
  29     avcodec_get_frame_defaults((AVFrame*)&s->picture);
  30     avctx->coded_frame = (AVFrame*)&s->picture;
  31
  32     return 0;
  33 }
  34
  35 static int bmp_decode_frame(AVCodecContext *avctx,
  36                             void *data, int *data_size,
  37                             const uint8_t *buf, int buf_size)
  38 {
  39     BMPContext *s = avctx->priv_data;
  40     AVFrame *picture = data;
  41     AVFrame *p = &s->picture;
  42     unsigned int fsize, hsize;
  43     int width, height;
  44     unsigned int depth;
  45     BiCompression comp;
  46     unsigned int ihsize;
  47     int i, j, n, linesize;
  48     uint32_t rgb[3];
  49     uint8_t *ptr;
  50     int dsize;
  51     const uint8_t *buf0 = buf;
  52
  53     if(buf_size < 14){
  54         av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
  55         return -1;
  56     }
  57
  58     if(bytestream_get_byte(&buf) != 'B' ||
  59        bytestream_get_byte(&buf) != 'M') {
  60         av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
  61         return -1;
  62     }
  63
  64     fsize = bytestream_get_le32(&buf);
  65     if(buf_size < fsize){
  66         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
  67                buf_size, fsize);
  68         return -1;
  69     }
  70
  71     buf += 2; /* reserved1 */
  72     buf += 2; /* reserved2 */
  73
  74     hsize = bytestream_get_le32(&buf); /* header size */
  75     if(fsize <= hsize){
  76         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
  77                fsize, hsize);
  78         return -1;
  79     }
  80
  81     ihsize = bytestream_get_le32(&buf);       /* more header size */
  82     if(ihsize + 14 > hsize){
  83         av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
  84         return -1;
  85     }
  86
  87     if (ihsize == 40) {
  88         width = bytestream_get_le32(&buf);
  89         height = bytestream_get_le32(&buf);
  90     } else if (ihsize == 12) {
  91         width  = bytestream_get_le16(&buf);
  92         height = bytestream_get_le16(&buf);
  93     } else {
  94         av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome");
  95         return -1;
  96     }
  97
  98     if(bytestream_get_le16(&buf) != 1){ /* planes */
  99         av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
 100         return -1;
 101     }
 102
 103     depth = bytestream_get_le16(&buf);
 104
 105     if(ihsize == 40)
 106         comp = bytestream_get_le32(&buf);
 107     else
 108         comp = BMP_RGB;
 109
 110     if(comp != BMP_RGB && comp != BMP_BITFIELDS){
 111         av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
 112         return -1;
 113     }
 114
 115     if(comp == BMP_BITFIELDS){
 116         buf += 20;
 117         rgb[0] = bytestream_get_le32(&buf);
 118         rgb[1] = bytestream_get_le32(&buf);
 119         rgb[2] = bytestream_get_le32(&buf);
 120     }
 121
 122     avctx->width = width;
 123     avctx->height = height > 0? height: -height;
 124
 125     avctx->pix_fmt = PIX_FMT_NONE;
 126
 127     switch(depth){
 128     case 32:
 129         if(comp == BMP_BITFIELDS){
 130             rgb[0] = (rgb[0] >> 15) & 3;
 131             rgb[1] = (rgb[1] >> 15) & 3;
 132             rgb[2] = (rgb[2] >> 15) & 3;
 133
 134             if(rgb[0] + rgb[1] + rgb[2] != 3 ||
 135                rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){
 136                 break;
 137             }
 138         } else {
 139             rgb[0] = 2;
 140             rgb[1] = 1;
 141             rgb[2] = 0;
 142         }
 143
 144         avctx->pix_fmt = PIX_FMT_BGR24;
 145         break;
 146     case 24:
 147         avctx->pix_fmt = PIX_FMT_BGR24;
 148         break;
 149     case 16:
 150         if(comp == BMP_RGB)
 151             avctx->pix_fmt = PIX_FMT_RGB555;
 152         break;
 153     default:
 154         av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
 155         return -1;
 156     }
 157
 158     if(avctx->pix_fmt == PIX_FMT_NONE){
 159         av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
 160         return -1;
 161     }
 162
 163     if(p->data[0])
 164         avctx->release_buffer(avctx, p);
 165
 166     p->reference = 0;
 167     if(avctx->get_buffer(avctx, p) < 0){
 168         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 169         return -1;
 170     }
 171     p->pict_type = FF_I_TYPE;
 172     p->key_frame = 1;
 173
 174     buf = buf0 + hsize;
 175     dsize = buf_size - hsize;
 176
 177     /* Line size in file multiple of 4 */
 178     n = (avctx->width * (depth / 8) + 3) & ~3;
 179
 180     if(n * avctx->height > dsize){
 181         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
 182                dsize, n * avctx->height);
 183         return -1;
 184     }
 185
 186     if(height > 0){
 187         ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
 188         linesize = -p->linesize[0];
 189     } else {
 190         ptr = p->data[0];
 191         linesize = p->linesize[0];
 192     }
 193
 194     switch(depth){
 195     case 24:
 196         for(i = 0; i < avctx->height; i++){
 197             memcpy(ptr, buf, avctx->width*(depth>>3));
 198             buf += n;
 199             ptr += linesize;
 200         }
 201         break;
 202     case 16:
 203         for(i = 0; i < avctx->height; i++){
 204             const uint16_t *src = (const uint16_t *) buf;
 205             uint16_t *dst = (uint16_t *) ptr;
 206
 207             for(j = 0; j < avctx->width; j++)
 208                 *dst++ = le2me_16(*src++);
 209
 210             buf += n;
 211             ptr += linesize;
 212         }
 213         break;
 214     case 32:
 215         for(i = 0; i < avctx->height; i++){
 216             const uint8_t *src = buf;
 217             uint8_t *dst = ptr;
 218
 219             for(j = 0; j < avctx->width; j++){
 220                 dst[0] = src[rgb[2]];
 221                 dst[1] = src[rgb[1]];
 222                 dst[2] = src[rgb[0]];
 223                 dst += 3;
 224                 src += 4;
 225             }
 226
 227             buf += n;
 228             ptr += linesize;
 229         }
 230         break;
 231     default:
 232         av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
 233         return -1;
 234     }
 235
 236     *picture = s->picture;
 237     *data_size = sizeof(AVPicture);
 238
 239     return buf_size;
 240 }
 241
 242 static av_cold int bmp_decode_end(AVCodecContext *avctx)
 243 {
 244     BMPContext* c = avctx->priv_data;
 245
 246     if (c->picture.data[0])
 247         avctx->release_buffer(avctx, &c->picture);
 248
 249     return 0;
 250 }
 251
 252 AVCodec bmp_decoder = {
 253     "bmp",
 254     CODEC_TYPE_VIDEO,
 255     CODEC_ID_BMP,
 256     sizeof(BMPContext),
 257     bmp_decode_init,
 258     NULL,
 259     bmp_decode_end,
 260     bmp_decode_frame,
 261     .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
 262 };