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 26#if CONFIG_ZLIB 27#include <zlib.h> 28#endif 29#include "libavutil/lzo.h" 30 31typedef struct { 32 AVFrame pic; 33 int linelen, height, bpp; 34 unsigned int decomp_size; 35 unsigned char* decomp_buf; 36} CamStudioContext; 37 38static void copy_frame_default(AVFrame *f, const uint8_t *src, 39 int linelen, int height) { 40 int i; 41 uint8_t *dst = f->data[0]; 42 dst += (height - 1) * f->linesize[0]; 43 for (i = height; i; i--) { 44 memcpy(dst, src, linelen); 45 src += linelen; 46 dst -= f->linesize[0]; 47 } 48} 49 50static void add_frame_default(AVFrame *f, const uint8_t *src, 51 int linelen, int height) { 52 int i, j; 53 uint8_t *dst = f->data[0]; 54 dst += (height - 1) * f->linesize[0]; 55 for (i = height; i; i--) { 56 for (j = linelen; j; j--) 57 *dst++ += *src++; 58 dst -= f->linesize[0] + linelen; 59 } 60} 61 62#if !HAVE_BIGENDIAN 63#define copy_frame_16 copy_frame_default 64#define copy_frame_32 copy_frame_default 65#define add_frame_16 add_frame_default 66#define add_frame_32 add_frame_default 67#else 68static void copy_frame_16(AVFrame *f, const uint8_t *src, 69 int linelen, int height) { 70 int i, j; 71 uint8_t *dst = f->data[0]; 72 dst += (height - 1) * f->linesize[0]; 73 for (i = height; i; i--) { 74 for (j = linelen / 2; j; j--) { 75 dst[0] = src[1]; 76 dst[1] = src[0]; 77 src += 2; 78 dst += 2; 79 } 80 dst -= f->linesize[0] + linelen; 81 } 82} 83 84static void copy_frame_32(AVFrame *f, const uint8_t *src, 85 int linelen, int height) { 86 int i, j; 87 uint8_t *dst = f->data[0]; 88 dst += (height - 1) * f->linesize[0]; 89 for (i = height; i; i--) { 90 for (j = linelen / 4; j; j--) { 91 dst[0] = src[3]; 92 dst[1] = src[2]; 93 dst[2] = src[1]; 94 dst[3] = src[0]; 95 src += 4; 96 dst += 4; 97 } 98 dst -= f->linesize[0] + linelen; 99 } 100} 101 102static void add_frame_16(AVFrame *f, const uint8_t *src, 103 int linelen, int height) { 104 int i, j; 105 uint8_t *dst = f->data[0]; 106 dst += (height - 1) * f->linesize[0]; 107 for (i = height; i; i--) { 108 for (j = linelen / 2; j; j--) { 109 dst[0] += src[1]; 110 dst[1] += src[0]; 111 src += 2; 112 dst += 2; 113 } 114 dst -= f->linesize[0] + linelen; 115 } 116} 117 118static void add_frame_32(AVFrame *f, const uint8_t *src, 119 int linelen, int height) { 120 int i, j; 121 uint8_t *dst = f->data[0]; 122 dst += (height - 1) * f->linesize[0]; 123 for (i = height; i; i--) { 124 for (j = linelen / 4; j; j--) { 125 dst[0] += src[3]; 126 dst[1] += src[2]; 127 dst[2] += src[1]; 128 dst[3] += src[0]; 129 src += 4; 130 dst += 4; 131 } 132 dst -= f->linesize[0] + linelen; 133 } 134} 135#endif 136 137static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, 138 AVPacket *avpkt) { 139 const uint8_t *buf = avpkt->data; 140 int buf_size = avpkt->size; 141 CamStudioContext *c = avctx->priv_data; 142 AVFrame *picture = data; 143 144 if (buf_size < 2) { 145 av_log(avctx, AV_LOG_ERROR, "coded frame too small\n"); 146 return -1; 147 } 148 149 if (c->pic.data[0]) 150 avctx->release_buffer(avctx, &c->pic); 151 c->pic.reference = 1; 152 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE | 153 FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; 154 if (avctx->get_buffer(avctx, &c->pic) < 0) { 155 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 156 return -1; 157 } 158 159 // decompress data 160 switch ((buf[0] >> 1) & 7) { 161 case 0: { // lzo compression 162 int outlen = c->decomp_size, inlen = buf_size - 2; 163 if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen)) 164 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n"); 165 break; 166 } 167 case 1: { // zlib compression 168#if CONFIG_ZLIB 169 unsigned long dlen = c->decomp_size; 170 if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK) 171 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n"); 172 break; 173#else 174 av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n"); 175 return -1; 176#endif 177 } 178 default: 179 av_log(avctx, AV_LOG_ERROR, "unknown compression\n"); 180 return -1; 181 } 182 183 // flip upside down, add difference frame 184 if (buf[0] & 1) { // keyframe 185 c->pic.pict_type = FF_I_TYPE; 186 c->pic.key_frame = 1; 187 switch (c->bpp) { 188 case 16: 189 copy_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height); 190 break; 191 case 32: 192 copy_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height); 193 break; 194 default: 195 copy_frame_default(&c->pic, c->decomp_buf, c->linelen, c->height); 196 } 197 } else { 198 c->pic.pict_type = FF_P_TYPE; 199 c->pic.key_frame = 0; 200 switch (c->bpp) { 201 case 16: 202 add_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height); 203 break; 204 case 32: 205 add_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height); 206 break; 207 default: 208 add_frame_default(&c->pic, c->decomp_buf, c->linelen, c->height); 209 } 210 } 211 212 *picture = c->pic; 213 *data_size = sizeof(AVFrame); 214 return buf_size; 215} 216 217static av_cold int decode_init(AVCodecContext *avctx) { 218 CamStudioContext *c = avctx->priv_data; 219 switch (avctx->bits_per_coded_sample) { 220 case 16: avctx->pix_fmt = PIX_FMT_RGB555; break; 221 case 24: avctx->pix_fmt = PIX_FMT_BGR24; break; 222 case 32: avctx->pix_fmt = PIX_FMT_RGB32; break; 223 default: 224 av_log(avctx, AV_LOG_ERROR, 225 "CamStudio codec error: invalid depth %i bpp\n", 226 avctx->bits_per_coded_sample); 227 return 1; 228 } 229 c->bpp = avctx->bits_per_coded_sample; 230 c->pic.data[0] = NULL; 231 c->linelen = avctx->width * avctx->bits_per_coded_sample / 8; 232 c->height = avctx->height; 233 c->decomp_size = c->height * c->linelen; 234 c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING); 235 if (!c->decomp_buf) { 236 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); 237 return 1; 238 } 239 return 0; 240} 241 242static av_cold int decode_end(AVCodecContext *avctx) { 243 CamStudioContext *c = avctx->priv_data; 244 av_freep(&c->decomp_buf); 245 if (c->pic.data[0]) 246 avctx->release_buffer(avctx, &c->pic); 247 return 0; 248} 249 250AVCodec cscd_decoder = { 251 "camstudio", 252 AVMEDIA_TYPE_VIDEO, 253 CODEC_ID_CSCD, 254 sizeof(CamStudioContext), 255 decode_init, 256 NULL, 257 decode_end, 258 decode_frame, 259 CODEC_CAP_DR1, 260 .long_name = NULL_IF_CONFIG_SMALL("CamStudio"), 261}; 262 263