libavcodec/bmp.c
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00001 /*
00002  * BMP image format decoder
00003  * Copyright (c) 2005 Mans Rullgard
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "avcodec.h"
00023 #include "bytestream.h"
00024 #include "bmp.h"
00025 #include "msrledec.h"
00026 
00027 static av_cold int bmp_decode_init(AVCodecContext *avctx){
00028     BMPContext *s = avctx->priv_data;
00029 
00030     avcodec_get_frame_defaults((AVFrame*)&s->picture);
00031     avctx->coded_frame = (AVFrame*)&s->picture;
00032 
00033     return 0;
00034 }
00035 
00036 static int bmp_decode_frame(AVCodecContext *avctx,
00037                             void *data, int *data_size,
00038                             AVPacket *avpkt)
00039 {
00040     const uint8_t *buf = avpkt->data;
00041     int buf_size = avpkt->size;
00042     BMPContext *s = avctx->priv_data;
00043     AVFrame *picture = data;
00044     AVFrame *p = &s->picture;
00045     unsigned int fsize, hsize;
00046     int width, height;
00047     unsigned int depth;
00048     BiCompression comp;
00049     unsigned int ihsize;
00050     int i, j, n, linesize;
00051     uint32_t rgb[3];
00052     uint8_t *ptr;
00053     int dsize;
00054     const uint8_t *buf0 = buf;
00055     GetByteContext gb;
00056 
00057     if(buf_size < 14){
00058         av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
00059         return -1;
00060     }
00061 
00062     if(bytestream_get_byte(&buf) != 'B' ||
00063        bytestream_get_byte(&buf) != 'M') {
00064         av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
00065         return -1;
00066     }
00067 
00068     fsize = bytestream_get_le32(&buf);
00069     if(buf_size < fsize){
00070         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d), trying to decode anyway\n",
00071                buf_size, fsize);
00072         fsize = buf_size;
00073     }
00074 
00075     buf += 2; /* reserved1 */
00076     buf += 2; /* reserved2 */
00077 
00078     hsize = bytestream_get_le32(&buf); /* header size */
00079     ihsize = bytestream_get_le32(&buf);       /* more header size */
00080     if(ihsize + 14 > hsize){
00081         av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
00082         return -1;
00083     }
00084 
00085     /* sometimes file size is set to some headers size, set a real size in that case */
00086     if(fsize == 14 || fsize == ihsize + 14)
00087         fsize = buf_size - 2;
00088 
00089     if(fsize <= hsize){
00090         av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n",
00091                fsize, hsize);
00092         return -1;
00093     }
00094 
00095     switch(ihsize){
00096     case  40: // windib v3
00097     case  64: // OS/2 v2
00098     case 108: // windib v4
00099     case 124: // windib v5
00100         width = bytestream_get_le32(&buf);
00101         height = bytestream_get_le32(&buf);
00102         break;
00103     case  12: // OS/2 v1
00104         width  = bytestream_get_le16(&buf);
00105         height = bytestream_get_le16(&buf);
00106         break;
00107     default:
00108         av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n");
00109         return -1;
00110     }
00111 
00112     if(bytestream_get_le16(&buf) != 1){ /* planes */
00113         av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
00114         return -1;
00115     }
00116 
00117     depth = bytestream_get_le16(&buf);
00118 
00119     if(ihsize == 40)
00120         comp = bytestream_get_le32(&buf);
00121     else
00122         comp = BMP_RGB;
00123 
00124     if(comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 && comp != BMP_RLE8){
00125         av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
00126         return -1;
00127     }
00128 
00129     if(comp == BMP_BITFIELDS){
00130         buf += 20;
00131         rgb[0] = bytestream_get_le32(&buf);
00132         rgb[1] = bytestream_get_le32(&buf);
00133         rgb[2] = bytestream_get_le32(&buf);
00134     }
00135 
00136     avctx->width = width;
00137     avctx->height = height > 0? height: -height;
00138 
00139     avctx->pix_fmt = PIX_FMT_NONE;
00140 
00141     switch(depth){
00142     case 32:
00143         if(comp == BMP_BITFIELDS){
00144             rgb[0] = (rgb[0] >> 15) & 3;
00145             rgb[1] = (rgb[1] >> 15) & 3;
00146             rgb[2] = (rgb[2] >> 15) & 3;
00147 
00148             if(rgb[0] + rgb[1] + rgb[2] != 3 ||
00149                rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){
00150                 break;
00151             }
00152         } else {
00153             rgb[0] = 2;
00154             rgb[1] = 1;
00155             rgb[2] = 0;
00156         }
00157 
00158         avctx->pix_fmt = PIX_FMT_BGR24;
00159         break;
00160     case 24:
00161         avctx->pix_fmt = PIX_FMT_BGR24;
00162         break;
00163     case 16:
00164         if(comp == BMP_RGB)
00165             avctx->pix_fmt = PIX_FMT_RGB555;
00166         else if (comp == BMP_BITFIELDS) {
00167             if (rgb[0] == 0xF800 && rgb[1] == 0x07E0 && rgb[2] == 0x001F)
00168                avctx->pix_fmt = PIX_FMT_RGB565;
00169             else if (rgb[0] == 0x7C00 && rgb[1] == 0x03E0 && rgb[2] == 0x001F)
00170                avctx->pix_fmt = PIX_FMT_RGB555;
00171             else if (rgb[0] == 0x0F00 && rgb[1] == 0x00F0 && rgb[2] == 0x000F)
00172                avctx->pix_fmt = PIX_FMT_RGB444;
00173             else {
00174                av_log(avctx, AV_LOG_ERROR, "Unknown bitfields %0X %0X %0X\n", rgb[0], rgb[1], rgb[2]);
00175                return AVERROR(EINVAL);
00176             }
00177         }
00178         break;
00179     case 8:
00180         if(hsize - ihsize - 14 > 0)
00181             avctx->pix_fmt = PIX_FMT_PAL8;
00182         else
00183             avctx->pix_fmt = PIX_FMT_GRAY8;
00184         break;
00185     case 1:
00186     case 4:
00187         if(hsize - ihsize - 14 > 0){
00188             avctx->pix_fmt = PIX_FMT_PAL8;
00189         }else{
00190             av_log(avctx, AV_LOG_ERROR, "Unknown palette for %d-colour BMP\n", 1<<depth);
00191             return -1;
00192         }
00193         break;
00194     default:
00195         av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
00196         return -1;
00197     }
00198 
00199     if(avctx->pix_fmt == PIX_FMT_NONE){
00200         av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
00201         return -1;
00202     }
00203 
00204     if(p->data[0])
00205         avctx->release_buffer(avctx, p);
00206 
00207     p->reference = 0;
00208     if(avctx->get_buffer(avctx, p) < 0){
00209         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00210         return -1;
00211     }
00212     p->pict_type = AV_PICTURE_TYPE_I;
00213     p->key_frame = 1;
00214 
00215     buf = buf0 + hsize;
00216     dsize = buf_size - hsize;
00217 
00218     /* Line size in file multiple of 4 */
00219     n = ((avctx->width * depth) / 8 + 3) & ~3;
00220 
00221     if(n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8){
00222         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
00223                dsize, n * avctx->height);
00224         return -1;
00225     }
00226 
00227     // RLE may skip decoding some picture areas, so blank picture before decoding
00228     if(comp == BMP_RLE4 || comp == BMP_RLE8)
00229         memset(p->data[0], 0, avctx->height * p->linesize[0]);
00230 
00231     if(height > 0){
00232         ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
00233         linesize = -p->linesize[0];
00234     } else {
00235         ptr = p->data[0];
00236         linesize = p->linesize[0];
00237     }
00238 
00239     if(avctx->pix_fmt == PIX_FMT_PAL8){
00240         int colors = 1 << depth;
00241 
00242         memset(p->data[1], 0, 1024);
00243 
00244         if(ihsize >= 36){
00245             int t;
00246             buf = buf0 + 46;
00247             t = bytestream_get_le32(&buf);
00248             if(t < 0 || t > (1 << depth)){
00249                 av_log(avctx, AV_LOG_ERROR, "Incorrect number of colors - %X for bitdepth %d\n", t, depth);
00250             }else if(t){
00251                 colors = t;
00252             }
00253         }
00254         buf = buf0 + 14 + ihsize; //palette location
00255         if((hsize-ihsize-14) < (colors << 2)){ // OS/2 bitmap, 3 bytes per palette entry
00256             for(i = 0; i < colors; i++)
00257                 ((uint32_t*)p->data[1])[i] = bytestream_get_le24(&buf);
00258         }else{
00259             for(i = 0; i < colors; i++)
00260                 ((uint32_t*)p->data[1])[i] = bytestream_get_le32(&buf);
00261         }
00262         buf = buf0 + hsize;
00263     }
00264     if(comp == BMP_RLE4 || comp == BMP_RLE8){
00265         if(height < 0){
00266             p->data[0] += p->linesize[0] * (avctx->height - 1);
00267             p->linesize[0] = -p->linesize[0];
00268         }
00269         bytestream2_init(&gb, buf, dsize);
00270         ff_msrle_decode(avctx, (AVPicture*)p, depth, &gb);
00271         if(height < 0){
00272             p->data[0] += p->linesize[0] * (avctx->height - 1);
00273             p->linesize[0] = -p->linesize[0];
00274         }
00275     }else{
00276         switch(depth){
00277         case 1:
00278             for (i = 0; i < avctx->height; i++) {
00279                 int j;
00280                 for (j = 0; j < n; j++) {
00281                     ptr[j*8+0] =  buf[j] >> 7;
00282                     ptr[j*8+1] = (buf[j] >> 6) & 1;
00283                     ptr[j*8+2] = (buf[j] >> 5) & 1;
00284                     ptr[j*8+3] = (buf[j] >> 4) & 1;
00285                     ptr[j*8+4] = (buf[j] >> 3) & 1;
00286                     ptr[j*8+5] = (buf[j] >> 2) & 1;
00287                     ptr[j*8+6] = (buf[j] >> 1) & 1;
00288                     ptr[j*8+7] =  buf[j]       & 1;
00289                 }
00290                 buf += n;
00291                 ptr += linesize;
00292             }
00293             break;
00294         case 8:
00295         case 24:
00296             for(i = 0; i < avctx->height; i++){
00297                 memcpy(ptr, buf, n);
00298                 buf += n;
00299                 ptr += linesize;
00300             }
00301             break;
00302         case 4:
00303             for(i = 0; i < avctx->height; i++){
00304                 int j;
00305                 for(j = 0; j < n; j++){
00306                     ptr[j*2+0] = (buf[j] >> 4) & 0xF;
00307                     ptr[j*2+1] = buf[j] & 0xF;
00308                 }
00309                 buf += n;
00310                 ptr += linesize;
00311             }
00312             break;
00313         case 16:
00314             for(i = 0; i < avctx->height; i++){
00315                 const uint16_t *src = (const uint16_t *) buf;
00316                 uint16_t *dst = (uint16_t *) ptr;
00317 
00318                 for(j = 0; j < avctx->width; j++)
00319                     *dst++ = av_le2ne16(*src++);
00320 
00321                 buf += n;
00322                 ptr += linesize;
00323             }
00324             break;
00325         case 32:
00326             for(i = 0; i < avctx->height; i++){
00327                 const uint8_t *src = buf;
00328                 uint8_t *dst = ptr;
00329 
00330                 for(j = 0; j < avctx->width; j++){
00331                     dst[0] = src[rgb[2]];
00332                     dst[1] = src[rgb[1]];
00333                     dst[2] = src[rgb[0]];
00334                     dst += 3;
00335                     src += 4;
00336                 }
00337 
00338                 buf += n;
00339                 ptr += linesize;
00340             }
00341             break;
00342         default:
00343             av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
00344             return -1;
00345         }
00346     }
00347 
00348     *picture = s->picture;
00349     *data_size = sizeof(AVPicture);
00350 
00351     return buf_size;
00352 }
00353 
00354 static av_cold int bmp_decode_end(AVCodecContext *avctx)
00355 {
00356     BMPContext* c = avctx->priv_data;
00357 
00358     if (c->picture.data[0])
00359         avctx->release_buffer(avctx, &c->picture);
00360 
00361     return 0;
00362 }
00363 
00364 AVCodec ff_bmp_decoder = {
00365     .name           = "bmp",
00366     .type           = AVMEDIA_TYPE_VIDEO,
00367     .id             = CODEC_ID_BMP,
00368     .priv_data_size = sizeof(BMPContext),
00369     .init           = bmp_decode_init,
00370     .close          = bmp_decode_end,
00371     .decode         = bmp_decode_frame,
00372     .capabilities   = CODEC_CAP_DR1,
00373     .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
00374 };