1 /*
2 * CamStudio decoder
3 * Copyright (c) 2006 Reimar Doeffinger
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21 #include <stdio.h>
22 #include <stdlib.h>
23
24 #include "avcodec.h"
25 #include "internal.h"
26 #include "libavutil/common.h"
27
28 #if CONFIG_ZLIB
29 #include <zlib.h>
30 #endif
31 #include "libavutil/lzo.h"
32
33 typedef struct CamStudioContext {
34 AVFrame *pic;
35 int linelen, height, bpp;
36 unsigned int decomp_size;
37 unsigned char* decomp_buf;
38 } CamStudioContext;
39
copy_frame_default(AVFrame * f,const uint8_t * src,int linelen,int height)40 static void copy_frame_default(AVFrame *f, const uint8_t *src,
41 int linelen, int height)
42 {
43 int i, src_stride = FFALIGN(linelen, 4);
44 uint8_t *dst = f->data[0];
45 dst += (height - 1) * f->linesize[0];
46 for (i = height; i; i--) {
47 memcpy(dst, src, linelen);
48 src += src_stride;
49 dst -= f->linesize[0];
50 }
51 }
52
add_frame_default(AVFrame * f,const uint8_t * src,int linelen,int height)53 static void add_frame_default(AVFrame *f, const uint8_t *src,
54 int linelen, int height)
55 {
56 int i, j, src_stride = FFALIGN(linelen, 4);
57 uint8_t *dst = f->data[0];
58 dst += (height - 1) * f->linesize[0];
59 for (i = height; i; i--) {
60 for (j = linelen; j; j--)
61 *dst++ += *src++;
62 src += src_stride - linelen;
63 dst -= f->linesize[0] + linelen;
64 }
65 }
66
decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)67 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
68 AVPacket *avpkt)
69 {
70 const uint8_t *buf = avpkt->data;
71 int buf_size = avpkt->size;
72 CamStudioContext *c = avctx->priv_data;
73 int ret;
74
75 if (buf_size < 2) {
76 av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
77 return AVERROR_INVALIDDATA;
78 }
79
80 if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0)
81 return ret;
82
83 // decompress data
84 switch ((buf[0] >> 1) & 7) {
85 case 0: { // lzo compression
86 int outlen = c->decomp_size, inlen = buf_size - 2;
87 if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen) || outlen) {
88 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
89 return AVERROR_INVALIDDATA;
90 }
91 break;
92 }
93 case 1: { // zlib compression
94 #if CONFIG_ZLIB
95 unsigned long dlen = c->decomp_size;
96 if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK || dlen != c->decomp_size) {
97 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
98 return AVERROR_INVALIDDATA;
99 }
100 break;
101 #else
102 av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
103 return AVERROR(ENOSYS);
104 #endif
105 }
106 default:
107 av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
108 return AVERROR_INVALIDDATA;
109 }
110
111 // flip upside down, add difference frame
112 if (buf[0] & 1) { // keyframe
113 c->pic->pict_type = AV_PICTURE_TYPE_I;
114 c->pic->key_frame = 1;
115 copy_frame_default(c->pic, c->decomp_buf,
116 c->linelen, c->height);
117 } else {
118 c->pic->pict_type = AV_PICTURE_TYPE_P;
119 c->pic->key_frame = 0;
120 add_frame_default(c->pic, c->decomp_buf,
121 c->linelen, c->height);
122 }
123
124 *got_frame = 1;
125 if ((ret = av_frame_ref(data, c->pic)) < 0)
126 return ret;
127
128 return buf_size;
129 }
130
decode_init(AVCodecContext * avctx)131 static av_cold int decode_init(AVCodecContext *avctx)
132 {
133 CamStudioContext *c = avctx->priv_data;
134 int stride;
135 switch (avctx->bits_per_coded_sample) {
136 case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555LE; break;
137 case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
138 case 32: avctx->pix_fmt = AV_PIX_FMT_BGR0; break;
139 default:
140 av_log(avctx, AV_LOG_ERROR,
141 "CamStudio codec error: invalid depth %i bpp\n",
142 avctx->bits_per_coded_sample);
143 return AVERROR_INVALIDDATA;
144 }
145 c->bpp = avctx->bits_per_coded_sample;
146 c->linelen = avctx->width * avctx->bits_per_coded_sample / 8;
147 c->height = avctx->height;
148 stride = FFALIGN(c->linelen, 4);
149 c->decomp_size = c->height * stride;
150 c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING);
151 if (!c->decomp_buf) {
152 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
153 return AVERROR(ENOMEM);
154 }
155 c->pic = av_frame_alloc();
156 if (!c->pic)
157 return AVERROR(ENOMEM);
158 return 0;
159 }
160
decode_end(AVCodecContext * avctx)161 static av_cold int decode_end(AVCodecContext *avctx)
162 {
163 CamStudioContext *c = avctx->priv_data;
164 av_freep(&c->decomp_buf);
165 av_frame_free(&c->pic);
166 return 0;
167 }
168
169 AVCodec ff_cscd_decoder = {
170 .name = "camstudio",
171 .long_name = NULL_IF_CONFIG_SMALL("CamStudio"),
172 .type = AVMEDIA_TYPE_VIDEO,
173 .id = AV_CODEC_ID_CSCD,
174 .priv_data_size = sizeof(CamStudioContext),
175 .init = decode_init,
176 .close = decode_end,
177 .decode = decode_frame,
178 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
179 .capabilities = AV_CODEC_CAP_DR1,
180 };
181