2 * BMP image format decoder
3 * Copyright (c) 2005 Mans Rullgard
5 * This file is part of FFmpeg.
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.
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.
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
23 #include "bytestream.h"
27 static av_cold int bmp_decode_init(AVCodecContext *avctx){
28 BMPContext *s = avctx->priv_data;
30 avcodec_get_frame_defaults((AVFrame*)&s->picture);
31 avctx->coded_frame = (AVFrame*)&s->picture;
36 static int bmp_decode_frame(AVCodecContext *avctx,
37 void *data, int *data_size,
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;
50 int i, j, n, linesize;
54 const uint8_t *buf0 = buf;
57 av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
61 if(bytestream_get_byte(&buf) != 'B' ||
62 bytestream_get_byte(&buf) != 'M') {
63 av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
67 fsize = bytestream_get_le32(&buf);
69 av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d), trying to decode anyway\n",
74 buf += 2; /* reserved1 */
75 buf += 2; /* reserved2 */
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);
84 /* sometimes file size is set to some headers size, set a real size in that case */
85 if(fsize == 14 || fsize == ihsize + 14)
89 av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n",
98 case 108: // windib v4
99 case 124: // windib v5
100 width = bytestream_get_le32(&buf);
101 height = bytestream_get_le32(&buf);
104 width = bytestream_get_le16(&buf);
105 height = bytestream_get_le16(&buf);
108 av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n");
112 if(bytestream_get_le16(&buf) != 1){ /* planes */
113 av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
117 depth = bytestream_get_le16(&buf);
119 if(ihsize == 40 || ihsize == 64 || ihsize == 56)
120 comp = bytestream_get_le32(&buf);
124 if(comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 && comp != BMP_RLE8){
125 av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
129 if(comp == BMP_BITFIELDS){
131 rgb[0] = bytestream_get_le32(&buf);
132 rgb[1] = bytestream_get_le32(&buf);
133 rgb[2] = bytestream_get_le32(&buf);
136 avctx->width = width;
137 avctx->height = height > 0? height: -height;
139 avctx->pix_fmt = PIX_FMT_NONE;
143 if(comp == BMP_BITFIELDS){
144 rgb[0] = (rgb[0] >> 15) & 3;
145 rgb[1] = (rgb[1] >> 15) & 3;
146 rgb[2] = (rgb[2] >> 15) & 3;
148 if(rgb[0] + rgb[1] + rgb[2] != 3 ||
149 rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){
158 avctx->pix_fmt = PIX_FMT_BGRA;
161 avctx->pix_fmt = PIX_FMT_BGR24;
165 avctx->pix_fmt = PIX_FMT_RGB555;
166 if(comp == BMP_BITFIELDS)
167 avctx->pix_fmt = rgb[1] == 0x07E0 ? PIX_FMT_RGB565 : PIX_FMT_RGB555;
170 if(hsize - ihsize - 14 > 0)
171 avctx->pix_fmt = PIX_FMT_PAL8;
173 avctx->pix_fmt = PIX_FMT_GRAY8;
177 if(hsize - ihsize - 14 > 0){
178 avctx->pix_fmt = PIX_FMT_PAL8;
180 av_log(avctx, AV_LOG_ERROR, "Unknown palette for %d-colour BMP\n", 1<<depth);
185 av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
189 if(avctx->pix_fmt == PIX_FMT_NONE){
190 av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
195 avctx->release_buffer(avctx, p);
198 if(avctx->get_buffer(avctx, p) < 0){
199 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
202 p->pict_type = AV_PICTURE_TYPE_I;
206 dsize = buf_size - hsize;
208 /* Line size in file multiple of 4 */
209 n = ((avctx->width * depth + 31) / 8) & ~3;
211 if(n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8){
212 av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
213 dsize, n * avctx->height);
217 // RLE may skip decoding some picture areas, so blank picture before decoding
218 if(comp == BMP_RLE4 || comp == BMP_RLE8)
219 memset(p->data[0], 0, avctx->height * p->linesize[0]);
221 if(depth == 4 || depth == 8)
222 memset(p->data[1], 0, 1024);
225 ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
226 linesize = -p->linesize[0];
229 linesize = p->linesize[0];
232 if(avctx->pix_fmt == PIX_FMT_PAL8){
233 int colors = 1 << depth;
237 t = bytestream_get_le32(&buf);
238 if(t < 0 || t > (1 << depth)){
239 av_log(avctx, AV_LOG_ERROR, "Incorrect number of colors - %X for bitdepth %d\n", t, depth);
244 buf = buf0 + 14 + ihsize; //palette location
245 if((hsize-ihsize-14) < (colors << 2)){ // OS/2 bitmap, 3 bytes per palette entry
246 for(i = 0; i < colors; i++)
247 ((uint32_t*)p->data[1])[i] = (0xff<<24) | bytestream_get_le24(&buf);
249 for(i = 0; i < colors; i++)
250 ((uint32_t*)p->data[1])[i] = 0xFFU << 24 | bytestream_get_le32(&buf);
254 if(comp == BMP_RLE4 || comp == BMP_RLE8){
256 p->data[0] += p->linesize[0] * (avctx->height - 1);
257 p->linesize[0] = -p->linesize[0];
259 ff_msrle_decode(avctx, (AVPicture*)p, depth, buf, dsize);
261 p->data[0] += p->linesize[0] * (avctx->height - 1);
262 p->linesize[0] = -p->linesize[0];
267 for (i = 0; i < avctx->height; i++) {
269 for (j = 0; j < n; j++) {
270 ptr[j*8+0] = buf[j] >> 7;
271 ptr[j*8+1] = (buf[j] >> 6) & 1;
272 ptr[j*8+2] = (buf[j] >> 5) & 1;
273 ptr[j*8+3] = (buf[j] >> 4) & 1;
274 ptr[j*8+4] = (buf[j] >> 3) & 1;
275 ptr[j*8+5] = (buf[j] >> 2) & 1;
276 ptr[j*8+6] = (buf[j] >> 1) & 1;
277 ptr[j*8+7] = buf[j] & 1;
285 for(i = 0; i < avctx->height; i++){
292 for(i = 0; i < avctx->height; i++){
294 for(j = 0; j < n; j++){
295 ptr[j*2+0] = (buf[j] >> 4) & 0xF;
296 ptr[j*2+1] = buf[j] & 0xF;
303 for(i = 0; i < avctx->height; i++){
304 const uint16_t *src = (const uint16_t *) buf;
305 uint16_t *dst = (uint16_t *) ptr;
307 for(j = 0; j < avctx->width; j++)
308 *dst++ = av_le2ne16(*src++);
315 for(i = 0; i < avctx->height; i++){
316 const uint8_t *src = buf;
319 for(j = 0; j < avctx->width; j++){
320 dst[0] = src[rgb[2]];
321 dst[1] = src[rgb[1]];
322 dst[2] = src[rgb[0]];
323 /* The Microsoft documentation states:
324 * "The high byte in each DWORD is not used."
325 * Both GIMP and ImageMagick store the alpha transparency value
326 * in the high byte for 32bit bmp files.
338 av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
343 *picture = s->picture;
344 *data_size = sizeof(AVPicture);
349 static av_cold int bmp_decode_end(AVCodecContext *avctx)
351 BMPContext* c = avctx->priv_data;
353 if (c->picture.data[0])
354 avctx->release_buffer(avctx, &c->picture);
359 AVCodec ff_bmp_decoder = {
361 .type = AVMEDIA_TYPE_VIDEO,
363 .priv_data_size = sizeof(BMPContext),
364 .init = bmp_decode_init,
365 .close = bmp_decode_end,
366 .decode = bmp_decode_frame,
367 .capabilities = CODEC_CAP_DR1,
368 .long_name = NULL_IF_CONFIG_SMALL("BMP image"),