1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
|
/*
* BMP image format
* Copyright (c) 2005 Mans Rullgard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avcodec.h"
#include "bitstream.h"
#include "bswap.h"
typedef struct BMPContext {
AVFrame picture;
} BMPContext;
#define BMP_RGB 0
#define BMP_RLE8 1
#define BMP_RLE4 2
#define BMP_BITFIELDS 3
#define read16(bits) bswap_16(get_bits(bits, 16))
#define read32(bits) bswap_32(get_bits_long(bits, 32))
static int bmp_decode_init(AVCodecContext *avctx){
BMPContext *s = avctx->priv_data;
avcodec_get_frame_defaults((AVFrame*)&s->picture);
avctx->coded_frame = (AVFrame*)&s->picture;
return 0;
}
static int bmp_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
BMPContext *s = avctx->priv_data;
AVFrame *picture = data;
AVFrame *p = &s->picture;
GetBitContext bits;
unsigned int fsize, hsize;
int width, height;
unsigned int depth;
unsigned int comp;
unsigned int ihsize;
int i, j, n, linesize;
uint32_t rgb[3];
uint8_t *ptr;
int dsize;
if(buf_size < 14){
av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
return -1;
}
init_get_bits(&bits, buf, buf_size);
if(get_bits(&bits, 16) != 0x424d){ /* 'BM' */
av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
return -1;
}
fsize = read32(&bits);
if(buf_size < fsize){
av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
buf_size, fsize);
return -1;
}
skip_bits(&bits, 16); /* reserved1 */
skip_bits(&bits, 16); /* reserved2 */
hsize = read32(&bits); /* header size */
if(fsize <= hsize){
av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
fsize, hsize);
return -1;
}
ihsize = read32(&bits); /* more header size */
if(ihsize + 14 > hsize){
av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
return -1;
}
width = read32(&bits);
height = read32(&bits);
if(read16(&bits) != 1){ /* planes */
av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
return -1;
}
depth = read16(&bits);
if(ihsize > 16)
comp = read32(&bits);
else
comp = BMP_RGB;
if(comp != BMP_RGB && comp != BMP_BITFIELDS){
av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
return -1;
}
if(comp == BMP_BITFIELDS){
skip_bits(&bits, 20 * 8);
rgb[0] = read32(&bits);
rgb[1] = read32(&bits);
rgb[2] = read32(&bits);
}
avctx->codec_id = CODEC_ID_BMP;
avctx->width = width;
avctx->height = height > 0? height: -height;
avctx->pix_fmt = PIX_FMT_NONE;
switch(depth){
case 32:
if(comp == BMP_BITFIELDS){
rgb[0] = (rgb[0] >> 15) & 3;
rgb[1] = (rgb[1] >> 15) & 3;
rgb[2] = (rgb[2] >> 15) & 3;
if(rgb[0] + rgb[1] + rgb[2] != 3 ||
rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){
break;
}
} else {
rgb[0] = 2;
rgb[1] = 1;
rgb[2] = 0;
}
avctx->pix_fmt = PIX_FMT_BGR24;
break;
case 24:
avctx->pix_fmt = PIX_FMT_BGR24;
break;
case 16:
if(comp == BMP_RGB)
avctx->pix_fmt = PIX_FMT_RGB555;
break;
default:
av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
return -1;
}
if(avctx->pix_fmt == PIX_FMT_NONE){
av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
return -1;
}
p->reference = 0;
if(avctx->get_buffer(avctx, p) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
p->pict_type = FF_I_TYPE;
p->key_frame = 1;
buf += hsize;
dsize = buf_size - hsize;
n = avctx->width * (depth / 8);
if(n * avctx->height > dsize){
av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
dsize, n * avctx->height);
return -1;
}
if(height > 0){
ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
linesize = -p->linesize[0];
} else {
ptr = p->data[0];
linesize = p->linesize[0];
}
switch(depth){
case 24:
for(i = 0; i < avctx->height; i++){
memcpy(ptr, buf, n);
buf += n;
ptr += linesize;
}
break;
case 16:
for(i = 0; i < avctx->height; i++){
uint16_t *src = (uint16_t *) buf;
uint16_t *dst = (uint16_t *) ptr;
for(j = 0; j < avctx->width; j++)
*dst++ = le2me_16(*src++);
buf += n;
ptr += linesize;
}
break;
case 32:
for(i = 0; i < avctx->height; i++){
uint8_t *src = buf;
uint8_t *dst = ptr;
for(j = 0; j < avctx->width; j++){
dst[0] = src[rgb[2]];
dst[1] = src[rgb[1]];
dst[2] = src[rgb[0]];
dst += 3;
src += 4;
}
buf += n;
ptr += linesize;
}
break;
default:
av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
return -1;
}
*picture = s->picture;
*data_size = sizeof(AVPicture);
return buf_size;
}
AVCodec bmp_decoder = {
"bmp",
CODEC_TYPE_VIDEO,
CODEC_ID_BMP,
sizeof(BMPContext),
bmp_decode_init,
NULL,
NULL,
bmp_decode_frame
};
|
