FFmpeg: libavcodec/bmp.c Source File

00001 /*
00002  * BMP image format decoder
00003  * Copyright (c) 2005 Mans Rullgard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 
00056     if(buf_size < 14){
00057         av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
00058         return -1;
00059     }
00060 
00061     if(bytestream_get_byte(&buf) != 'B' ||
00062        bytestream_get_byte(&buf) != 'M') {
00063         av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
00064         return -1;
00065     }
00066 
00067     fsize = bytestream_get_le32(&buf);
00068     if(buf_size < fsize){
00069         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d), trying to decode anyway\n",
00070                buf_size, fsize);
00071         fsize = buf_size;
00072     }
00073 
00074     buf += 2; /* reserved1 */
00075     buf += 2; /* reserved2 */
00076 
00077     hsize = bytestream_get_le32(&buf); /* header size */
00078     ihsize = bytestream_get_le32(&buf);       /* more header size */
00079     if(ihsize + 14 > hsize){
00080         av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
00081         return -1;
00082     }
00083 
00084     /* sometimes file size is set to some headers size, set a real size in that case */
00085     if(fsize == 14 || fsize == ihsize + 14)
00086         fsize = buf_size - 2;
00087 
00088     if(fsize <= hsize){
00089         av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n",
00090                fsize, hsize);
00091         return -1;
00092     }
00093 
00094     switch(ihsize){
00095     case  40: // windib
00096     case  56: // 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 || ihsize == 64 || ihsize == 56)
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_BGRA;
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         if(comp == BMP_BITFIELDS)
00167             avctx->pix_fmt = rgb[1] == 0x07E0 ? PIX_FMT_RGB565 : PIX_FMT_RGB555;
00168         break;
00169     case 8:
00170         if(hsize - ihsize - 14 > 0)
00171             avctx->pix_fmt = PIX_FMT_PAL8;
00172         else
00173             avctx->pix_fmt = PIX_FMT_GRAY8;
00174         break;
00175     case 1:
00176     case 4:
00177         if(hsize - ihsize - 14 > 0){
00178             avctx->pix_fmt = PIX_FMT_PAL8;
00179         }else{
00180             av_log(avctx, AV_LOG_ERROR, "Unknown palette for %d-colour BMP\n", 1<<depth);
00181             return -1;
00182         }
00183         break;
00184     default:
00185         av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
00186         return -1;
00187     }
00188 
00189     if(avctx->pix_fmt == PIX_FMT_NONE){
00190         av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
00191         return -1;
00192     }
00193 
00194     if(p->data[0])
00195         avctx->release_buffer(avctx, p);
00196 
00197     p->reference = 0;
00198     if(avctx->get_buffer(avctx, p) < 0){
00199         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
00200         return -1;
00201     }
00202     p->pict_type = AV_PICTURE_TYPE_I;
00203     p->key_frame = 1;
00204 
00205     buf = buf0 + hsize;
00206     dsize = buf_size - hsize;
00207 
00208     /* Line size in file multiple of 4 */
00209     n = ((avctx->width * depth + 31) / 8) & ~3;
00210 
00211     if(n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8){
00212         av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
00213                dsize, n * avctx->height);
00214         return -1;
00215     }
00216 
00217     // RLE may skip decoding some picture areas, so blank picture before decoding
00218     if(comp == BMP_RLE4 || comp == BMP_RLE8)
00219         memset(p->data[0], 0, avctx->height * p->linesize[0]);
00220 
00221     if(depth == 4 || depth == 8)
00222         memset(p->data[1], 0, 1024);
00223 
00224     if(height > 0){
00225         ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
00226         linesize = -p->linesize[0];
00227     } else {
00228         ptr = p->data[0];
00229         linesize = p->linesize[0];
00230     }
00231 
00232     if(avctx->pix_fmt == PIX_FMT_PAL8){
00233         int colors = 1 << depth;
00234         if(ihsize >= 36){
00235             int t;
00236             buf = buf0 + 46;
00237             t = bytestream_get_le32(&buf);
00238             if(t < 0 || t > (1 << depth)){
00239                 av_log(avctx, AV_LOG_ERROR, "Incorrect number of colors - %X for bitdepth %d\n", t, depth);
00240             }else if(t){
00241                 colors = t;
00242             }
00243         }
00244         buf = buf0 + 14 + ihsize; //palette location
00245         if((hsize-ihsize-14) < (colors << 2)){ // OS/2 bitmap, 3 bytes per palette entry
00246             for(i = 0; i < colors; i++)
00247                 ((uint32_t*)p->data[1])[i] = (0xff<<24) | bytestream_get_le24(&buf);
00248         }else{
00249             for(i = 0; i < colors; i++)
00250                 ((uint32_t*)p->data[1])[i] = bytestream_get_le32(&buf);
00251         }
00252         buf = buf0 + hsize;
00253     }
00254     if(comp == BMP_RLE4 || comp == BMP_RLE8){
00255         if(height < 0){
00256             p->data[0] += p->linesize[0] * (avctx->height - 1);
00257             p->linesize[0] = -p->linesize[0];
00258         }
00259         ff_msrle_decode(avctx, (AVPicture*)p, depth, buf, dsize);
00260         if(height < 0){
00261             p->data[0] += p->linesize[0] * (avctx->height - 1);
00262             p->linesize[0] = -p->linesize[0];
00263         }
00264     }else{
00265         switch(depth){
00266         case 1:
00267             for (i = 0; i < avctx->height; i++) {
00268                 int j;
00269                 for (j = 0; j < n; j++) {
00270                     ptr[j*8+0] =  buf[j] >> 7;
00271                     ptr[j*8+1] = (buf[j] >> 6) & 1;
00272                     ptr[j*8+2] = (buf[j] >> 5) & 1;
00273                     ptr[j*8+3] = (buf[j] >> 4) & 1;
00274                     ptr[j*8+4] = (buf[j] >> 3) & 1;
00275                     ptr[j*8+5] = (buf[j] >> 2) & 1;
00276                     ptr[j*8+6] = (buf[j] >> 1) & 1;
00277                     ptr[j*8+7] =  buf[j]       & 1;
00278                 }
00279                 buf += n;
00280                 ptr += linesize;
00281             }
00282             break;
00283         case 8:
00284         case 24:
00285             for(i = 0; i < avctx->height; i++){
00286                 memcpy(ptr, buf, n);
00287                 buf += n;
00288                 ptr += linesize;
00289             }
00290             break;
00291         case 4:
00292             for(i = 0; i < avctx->height; i++){
00293                 int j;
00294                 for(j = 0; j < n; j++){
00295                     ptr[j*2+0] = (buf[j] >> 4) & 0xF;
00296                     ptr[j*2+1] = buf[j] & 0xF;
00297                 }
00298                 buf += n;
00299                 ptr += linesize;
00300             }
00301             break;
00302         case 16:
00303             for(i = 0; i < avctx->height; i++){
00304                 const uint16_t *src = (const uint16_t *) buf;
00305                 uint16_t *dst = (uint16_t *) ptr;
00306 
00307                 for(j = 0; j < avctx->width; j++)
00308                     *dst++ = av_le2ne16(*src++);
00309 
00310                 buf += n;
00311                 ptr += linesize;
00312             }
00313             break;
00314         case 32:
00315             for(i = 0; i < avctx->height; i++){
00316                 const uint8_t *src = buf;
00317                 uint8_t *dst = ptr;
00318 
00319                 for(j = 0; j < avctx->width; j++){
00320                     dst[0] = src[rgb[2]];
00321                     dst[1] = src[rgb[1]];
00322                     dst[2] = src[rgb[0]];
00323 /* The Microsoft documentation states:
00324  * "The high byte in each DWORD is not used."
00325  * Both GIMP and ImageMagick store the alpha transparency value
00326  * in the high byte for 32bit bmp files.
00327  */
00328                     dst[3] = src[3];
00329                     dst += 4;
00330                     src += 4;
00331                 }
00332 
00333                 buf += n;
00334                 ptr += linesize;
00335             }
00336             break;
00337         default:
00338             av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
00339             return -1;
00340         }
00341     }
00342 
00343     *picture = s->picture;
00344     *data_size = sizeof(AVPicture);
00345 
00346     return buf_size;
00347 }
00348 
00349 static av_cold int bmp_decode_end(AVCodecContext *avctx)
00350 {
00351     BMPContext* c = avctx->priv_data;
00352 
00353     if (c->picture.data[0])
00354         avctx->release_buffer(avctx, &c->picture);
00355 
00356     return 0;
00357 }
00358 
00359 AVCodec ff_bmp_decoder = {
00360     .name           = "bmp",
00361     .type           = AVMEDIA_TYPE_VIDEO,
00362     .id             = CODEC_ID_BMP,
00363     .priv_data_size = sizeof(BMPContext),
00364     .init           = bmp_decode_init,
00365     .close          = bmp_decode_end,
00366     .decode         = bmp_decode_frame,
00367     .capabilities   = CODEC_CAP_DR1,
00368     .long_name = NULL_IF_CONFIG_SMALL("BMP image"),
00369 };