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
|
/*
* CamStudio decoder
* Copyright (c) 2006 Reimar Doeffinger
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; 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 {
AVFrame *pic;
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 linelen, int height)
{
int i, src_stride = FFALIGN(linelen, 4);
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 linelen, int height)
{
int i, j, src_stride = FFALIGN(linelen, 4);
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;
}
}
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;
int ret;
if (buf_size < 2) {
av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
return AVERROR_INVALIDDATA;
}
if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0)
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) || outlen) {
av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
return AVERROR_INVALIDDATA;
}
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");
return AVERROR_INVALIDDATA;
}
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
c->pic->pict_type = AV_PICTURE_TYPE_I;
c->pic->key_frame = 1;
copy_frame_default(c->pic, c->decomp_buf,
c->linelen, c->height);
} else {
c->pic->pict_type = AV_PICTURE_TYPE_P;
c->pic->key_frame = 0;
add_frame_default(c->pic, c->decomp_buf,
c->linelen, c->height);
}
*got_frame = 1;
if ((ret = av_frame_ref(data, c->pic)) < 0)
return ret;
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_RGB555LE; break;
case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
case 32: avctx->pix_fmt = AV_PIX_FMT_BGR0; 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 = FFALIGN(c->linelen, 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);
}
c->pic = av_frame_alloc();
if (!c->pic)
return AVERROR(ENOMEM);
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx)
{
CamStudioContext *c = avctx->priv_data;
av_freep(&c->decomp_buf);
av_frame_free(&c->pic);
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,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
.capabilities = AV_CODEC_CAP_DR1,
};
|
