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#ifndef WORDS_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 const uint8_t *buf, int buf_size) { 139 CamStudioContext *c = avctx->priv_data; 140 AVFrame *picture = data; 141 142 if (buf_size < 2) { 143 av_log(avctx, AV_LOG_ERROR, "coded frame too small\n"); 144 return -1; 145 } 146 147 if (c->pic.data[0]) 148 avctx->release_buffer(avctx, &c->pic); 149 c->pic.reference = 1; 150 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE | 151 FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; 152 if (avctx->get_buffer(avctx, &c->pic) < 0) { 153 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 154 return -1; 155 } 156 157 // decompress data 158 switch ((buf[0] >> 1) & 7) { 159 case 0: { // lzo compression 160 int outlen = c->decomp_size, inlen = buf_size - 2; 161 if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen)) 162 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n"); 163 break; 164 } 165 case 1: { // zlib compression 166#if CONFIG_ZLIB 167 unsigned long dlen = c->decomp_size; 168 if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK) 169 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n"); 170 break; 171#else 172 av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n"); 173 return -1; 174#endif 175 } 176 default: 177 av_log(avctx, AV_LOG_ERROR, "unknown compression\n"); 178 return -1; 179 } 180 181 // flip upside down, add difference frame 182 if (buf[0] & 1) { // keyframe 183 c->pic.pict_type = FF_I_TYPE; 184 c->pic.key_frame = 1; 185 switch (c->bpp) { 186 case 16: 187 copy_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height); 188 break; 189 case 32: 190 copy_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height); 191 break; 192 default: 193 copy_frame_default(&c->pic, c->decomp_buf, c->linelen, c->height); 194 } 195 } else { 196 c->pic.pict_type = FF_P_TYPE; 197 c->pic.key_frame = 0; 198 switch (c->bpp) { 199 case 16: 200 add_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height); 201 break; 202 case 32: 203 add_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height); 204 break; 205 default: 206 add_frame_default(&c->pic, c->decomp_buf, c->linelen, c->height); 207 } 208 } 209 210 *picture = c->pic; 211 *data_size = sizeof(AVFrame); 212 return buf_size; 213} 214 215static av_cold int decode_init(AVCodecContext *avctx) { 216 CamStudioContext *c = avctx->priv_data; 217 if (avcodec_check_dimensions(avctx, avctx->height, avctx->width) < 0) { 218 return 1; 219 } 220 switch (avctx->bits_per_coded_sample) { 221 case 16: avctx->pix_fmt = PIX_FMT_RGB555; break; 222 case 24: avctx->pix_fmt = PIX_FMT_BGR24; break; 223 case 32: avctx->pix_fmt = PIX_FMT_RGB32; break; 224 default: 225 av_log(avctx, AV_LOG_ERROR, 226 "CamStudio codec error: invalid depth %i bpp\n", 227 avctx->bits_per_coded_sample); 228 return 1; 229 } 230 c->bpp = avctx->bits_per_coded_sample; 231 c->pic.data[0] = NULL; 232 c->linelen = avctx->width * avctx->bits_per_coded_sample / 8; 233 c->height = avctx->height; 234 c->decomp_size = c->height * c->linelen; 235 c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING); 236 if (!c->decomp_buf) { 237 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); 238 return 1; 239 } 240 return 0; 241} 242 243static av_cold int decode_end(AVCodecContext *avctx) { 244 CamStudioContext *c = avctx->priv_data; 245 av_freep(&c->decomp_buf); 246 if (c->pic.data[0]) 247 avctx->release_buffer(avctx, &c->pic); 248 return 0; 249} 250 251AVCodec cscd_decoder = { 252 "camstudio", 253 CODEC_TYPE_VIDEO, 254 CODEC_ID_CSCD, 255 sizeof(CamStudioContext), 256 decode_init, 257 NULL, 258 decode_end, 259 decode_frame, 260 CODEC_CAP_DR1, 261 .long_name = NULL_IF_CONFIG_SMALL("CamStudio"), 262}; 263 264