1/* 2 * CamStudio decoder 3 * Copyright (c) 2006 Reimar Doeffinger 4 * 5 * This file is part of Libav. 6 * 7 * Libav 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 * Libav 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 Libav; 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, int src_stride, 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 += src_stride; 46 dst -= f->linesize[0]; 47 } 48} 49 50static void add_frame_default(AVFrame *f, const uint8_t *src, int src_stride, 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 src += src_stride - linelen; 59 dst -= f->linesize[0] + linelen; 60 } 61} 62 63#if !HAVE_BIGENDIAN 64#define copy_frame_16(f, s, l, h) copy_frame_default(f, s, l, l, h) 65#define copy_frame_32(f, s, l, h) copy_frame_default(f, s, l, l, h) 66#define add_frame_16(f, s, l, h) add_frame_default(f, s, l, l, h) 67#define add_frame_32(f, s, l, h) add_frame_default(f, s, l, l, h) 68#else 69static void copy_frame_16(AVFrame *f, const uint8_t *src, 70 int linelen, int height) { 71 int i, j; 72 uint8_t *dst = f->data[0]; 73 dst += (height - 1) * f->linesize[0]; 74 for (i = height; i; i--) { 75 for (j = linelen / 2; j; j--) { 76 dst[0] = src[1]; 77 dst[1] = src[0]; 78 src += 2; 79 dst += 2; 80 } 81 dst -= f->linesize[0] + linelen; 82 } 83} 84 85static void copy_frame_32(AVFrame *f, const uint8_t *src, 86 int linelen, int height) { 87 int i, j; 88 uint8_t *dst = f->data[0]; 89 dst += (height - 1) * f->linesize[0]; 90 for (i = height; i; i--) { 91 for (j = linelen / 4; j; j--) { 92 dst[0] = src[3]; 93 dst[1] = src[2]; 94 dst[2] = src[1]; 95 dst[3] = src[0]; 96 src += 4; 97 dst += 4; 98 } 99 dst -= f->linesize[0] + linelen; 100 } 101} 102 103static void add_frame_16(AVFrame *f, const uint8_t *src, 104 int linelen, int height) { 105 int i, j; 106 uint8_t *dst = f->data[0]; 107 dst += (height - 1) * f->linesize[0]; 108 for (i = height; i; i--) { 109 for (j = linelen / 2; j; j--) { 110 dst[0] += src[1]; 111 dst[1] += src[0]; 112 src += 2; 113 dst += 2; 114 } 115 dst -= f->linesize[0] + linelen; 116 } 117} 118 119static void add_frame_32(AVFrame *f, const uint8_t *src, 120 int linelen, int height) { 121 int i, j; 122 uint8_t *dst = f->data[0]; 123 dst += (height - 1) * f->linesize[0]; 124 for (i = height; i; i--) { 125 for (j = linelen / 4; j; j--) { 126 dst[0] += src[3]; 127 dst[1] += src[2]; 128 dst[2] += src[1]; 129 dst[3] += src[0]; 130 src += 4; 131 dst += 4; 132 } 133 dst -= f->linesize[0] + linelen; 134 } 135} 136#endif 137 138static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, 139 AVPacket *avpkt) { 140 const uint8_t *buf = avpkt->data; 141 int buf_size = avpkt->size; 142 CamStudioContext *c = avctx->priv_data; 143 AVFrame *picture = data; 144 145 if (buf_size < 2) { 146 av_log(avctx, AV_LOG_ERROR, "coded frame too small\n"); 147 return -1; 148 } 149 150 if (c->pic.data[0]) 151 avctx->release_buffer(avctx, &c->pic); 152 c->pic.reference = 1; 153 c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE | 154 FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; 155 if (avctx->get_buffer(avctx, &c->pic) < 0) { 156 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); 157 return -1; 158 } 159 160 // decompress data 161 switch ((buf[0] >> 1) & 7) { 162 case 0: { // lzo compression 163 int outlen = c->decomp_size, inlen = buf_size - 2; 164 if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen)) 165 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n"); 166 break; 167 } 168 case 1: { // zlib compression 169#if CONFIG_ZLIB 170 unsigned long dlen = c->decomp_size; 171 if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK) 172 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n"); 173 break; 174#else 175 av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n"); 176 return -1; 177#endif 178 } 179 default: 180 av_log(avctx, AV_LOG_ERROR, "unknown compression\n"); 181 return -1; 182 } 183 184 // flip upside down, add difference frame 185 if (buf[0] & 1) { // keyframe 186 c->pic.pict_type = AV_PICTURE_TYPE_I; 187 c->pic.key_frame = 1; 188 switch (c->bpp) { 189 case 16: 190 copy_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height); 191 break; 192 case 32: 193 copy_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height); 194 break; 195 default: 196 copy_frame_default(&c->pic, c->decomp_buf, FFALIGN(c->linelen, 4), 197 c->linelen, c->height); 198 } 199 } else { 200 c->pic.pict_type = AV_PICTURE_TYPE_P; 201 c->pic.key_frame = 0; 202 switch (c->bpp) { 203 case 16: 204 add_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height); 205 break; 206 case 32: 207 add_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height); 208 break; 209 default: 210 add_frame_default(&c->pic, c->decomp_buf, FFALIGN(c->linelen, 4), 211 c->linelen, c->height); 212 } 213 } 214 215 *picture = c->pic; 216 *data_size = sizeof(AVFrame); 217 return buf_size; 218} 219 220static av_cold int decode_init(AVCodecContext *avctx) { 221 CamStudioContext *c = avctx->priv_data; 222 int stride; 223 switch (avctx->bits_per_coded_sample) { 224 case 16: avctx->pix_fmt = PIX_FMT_RGB555; break; 225 case 24: avctx->pix_fmt = PIX_FMT_BGR24; break; 226 case 32: avctx->pix_fmt = PIX_FMT_RGB32; break; 227 default: 228 av_log(avctx, AV_LOG_ERROR, 229 "CamStudio codec error: invalid depth %i bpp\n", 230 avctx->bits_per_coded_sample); 231 return AVERROR_INVALIDDATA; 232 } 233 c->bpp = avctx->bits_per_coded_sample; 234 c->pic.data[0] = NULL; 235 c->linelen = avctx->width * avctx->bits_per_coded_sample / 8; 236 c->height = avctx->height; 237 stride = c->linelen; 238 if (avctx->bits_per_coded_sample == 24) 239 stride = FFALIGN(stride, 4); 240 c->decomp_size = c->height * stride; 241 c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING); 242 if (!c->decomp_buf) { 243 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); 244 return AVERROR(ENOMEM); 245 } 246 return 0; 247} 248 249static av_cold int decode_end(AVCodecContext *avctx) { 250 CamStudioContext *c = avctx->priv_data; 251 av_freep(&c->decomp_buf); 252 if (c->pic.data[0]) 253 avctx->release_buffer(avctx, &c->pic); 254 return 0; 255} 256 257AVCodec ff_cscd_decoder = { 258 .name = "camstudio", 259 .type = AVMEDIA_TYPE_VIDEO, 260 .id = CODEC_ID_CSCD, 261 .priv_data_size = sizeof(CamStudioContext), 262 .init = decode_init, 263 .close = decode_end, 264 .decode = decode_frame, 265 .capabilities = CODEC_CAP_DR1, 266 .long_name = NULL_IF_CONFIG_SMALL("CamStudio"), 267}; 268 269