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
252
253
254
255
256
257
258
259
260
|
/*
* CamStudio decoder
* Copyright (c) 2006 Reimar Doeffinger
*
* This file is part of Libav.
*
* Libav 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 2.1 of the License, or (at your option) any later version.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include "avcodec.h"
#include "internal.h"
#include "libavutil/common.h"
#if CONFIG_ZLIB
#include <zlib.h>
#endif
#include "libavutil/lzo.h"
typedef struct CamStudioContext {
int linelen, height, bpp;
unsigned int decomp_size;
unsigned char* decomp_buf;
} CamStudioContext;
static void copy_frame_default(AVFrame *f, const uint8_t *src, int src_stride,
int linelen, int height) {
int i;
uint8_t *dst = f->data[0];
dst += (height - 1) * f->linesize[0];
for (i = height; i; i--) {
memcpy(dst, src, linelen);
src += src_stride;
dst -= f->linesize[0];
}
}
static void add_frame_default(AVFrame *f, const uint8_t *src, int src_stride,
int linelen, int height) {
int i, j;
uint8_t *dst = f->data[0];
dst += (height - 1) * f->linesize[0];
for (i = height; i; i--) {
for (j = linelen; j; j--)
*dst++ += *src++;
src += src_stride - linelen;
dst -= f->linesize[0] + linelen;
}
}
#if !HAVE_BIGENDIAN
#define copy_frame_16(f, s, l, h) copy_frame_default(f, s, l, l, h)
#define copy_frame_32(f, s, l, h) copy_frame_default(f, s, l, l, h)
#define add_frame_16(f, s, l, h) add_frame_default(f, s, l, l, h)
#define add_frame_32(f, s, l, h) add_frame_default(f, s, l, l, h)
#else
static void copy_frame_16(AVFrame *f, const uint8_t *src,
int linelen, int height) {
int i, j;
uint8_t *dst = f->data[0];
dst += (height - 1) * f->linesize[0];
for (i = height; i; i--) {
for (j = linelen / 2; j; j--) {
dst[0] = src[1];
dst[1] = src[0];
src += 2;
dst += 2;
}
dst -= f->linesize[0] + linelen;
}
}
static void copy_frame_32(AVFrame *f, const uint8_t *src,
int linelen, int height) {
int i, j;
uint8_t *dst = f->data[0];
dst += (height - 1) * f->linesize[0];
for (i = height; i; i--) {
for (j = linelen / 4; j; j--) {
dst[0] = src[3];
dst[1] = src[2];
dst[2] = src[1];
dst[3] = src[0];
src += 4;
dst += 4;
}
dst -= f->linesize[0] + linelen;
}
}
static void add_frame_16(AVFrame *f, const uint8_t *src,
int linelen, int height) {
int i, j;
uint8_t *dst = f->data[0];
dst += (height - 1) * f->linesize[0];
for (i = height; i; i--) {
for (j = linelen / 2; j; j--) {
dst[0] += src[1];
dst[1] += src[0];
src += 2;
dst += 2;
}
dst -= f->linesize[0] + linelen;
}
}
static void add_frame_32(AVFrame *f, const uint8_t *src,
int linelen, int height) {
int i, j;
uint8_t *dst = f->data[0];
dst += (height - 1) * f->linesize[0];
for (i = height; i; i--) {
for (j = linelen / 4; j; j--) {
dst[0] += src[3];
dst[1] += src[2];
dst[2] += src[1];
dst[3] += src[0];
src += 4;
dst += 4;
}
dst -= f->linesize[0] + linelen;
}
}
#endif
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt) {
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
CamStudioContext *c = avctx->priv_data;
AVFrame *picture = data;
int ret;
if (buf_size < 2) {
av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
return AVERROR_INVALIDDATA;
}
if ((ret = ff_get_buffer(avctx, picture, 0)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
// decompress data
switch ((buf[0] >> 1) & 7) {
case 0: { // lzo compression
int outlen = c->decomp_size, inlen = buf_size - 2;
if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen))
av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
break;
}
case 1: { // zlib compression
#if CONFIG_ZLIB
unsigned long dlen = c->decomp_size;
if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK)
av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
break;
#else
av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
return AVERROR(ENOSYS);
#endif
}
default:
av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
return AVERROR_INVALIDDATA;
}
// flip upside down, add difference frame
if (buf[0] & 1) { // keyframe
picture->pict_type = AV_PICTURE_TYPE_I;
picture->key_frame = 1;
switch (c->bpp) {
case 16:
copy_frame_16(picture, c->decomp_buf, c->linelen, c->height);
break;
case 32:
copy_frame_32(picture, c->decomp_buf, c->linelen, c->height);
break;
default:
copy_frame_default(picture, c->decomp_buf, FFALIGN(c->linelen, 4),
c->linelen, c->height);
}
} else {
picture->pict_type = AV_PICTURE_TYPE_P;
picture->key_frame = 0;
switch (c->bpp) {
case 16:
add_frame_16(picture, c->decomp_buf, c->linelen, c->height);
break;
case 32:
add_frame_32(picture, c->decomp_buf, c->linelen, c->height);
break;
default:
add_frame_default(picture, c->decomp_buf, FFALIGN(c->linelen, 4),
c->linelen, c->height);
}
}
*got_frame = 1;
return buf_size;
}
static av_cold int decode_init(AVCodecContext *avctx) {
CamStudioContext *c = avctx->priv_data;
int stride;
switch (avctx->bits_per_coded_sample) {
case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
default:
av_log(avctx, AV_LOG_ERROR,
"CamStudio codec error: invalid depth %i bpp\n",
avctx->bits_per_coded_sample);
return AVERROR_INVALIDDATA;
}
c->bpp = avctx->bits_per_coded_sample;
c->linelen = avctx->width * avctx->bits_per_coded_sample / 8;
c->height = avctx->height;
stride = c->linelen;
if (avctx->bits_per_coded_sample == 24)
stride = FFALIGN(stride, 4);
c->decomp_size = c->height * stride;
c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING);
if (!c->decomp_buf) {
av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
return AVERROR(ENOMEM);
}
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx) {
CamStudioContext *c = avctx->priv_data;
av_freep(&c->decomp_buf);
return 0;
}
AVCodec ff_cscd_decoder = {
.name = "camstudio",
.long_name = NULL_IF_CONFIG_SMALL("CamStudio"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_CSCD,
.priv_data_size = sizeof(CamStudioContext),
.init = decode_init,
.close = decode_end,
.decode = decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};
|
