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 33typedef struct { 34 AVFrame *pic; 35 int linelen, height, bpp; 36 unsigned int decomp_size; 37 unsigned char* decomp_buf; 38} CamStudioContext; 39 40static void copy_frame_default(AVFrame *f, const uint8_t *src, 41 int linelen, int height) { 42 int i, src_stride = FFALIGN(linelen, 4); 43 uint8_t *dst = f->data[0]; 44 dst += (height - 1) * f->linesize[0]; 45 for (i = height; i; i--) { 46 memcpy(dst, src, linelen); 47 src += src_stride; 48 dst -= f->linesize[0]; 49 } 50} 51 52static void add_frame_default(AVFrame *f, const uint8_t *src, 53 int linelen, int height) { 54 int i, j, src_stride = FFALIGN(linelen, 4); 55 uint8_t *dst = f->data[0]; 56 dst += (height - 1) * f->linesize[0]; 57 for (i = height; i; i--) { 58 for (j = linelen; j; j--) 59 *dst++ += *src++; 60 src += src_stride - linelen; 61 dst -= f->linesize[0] + linelen; 62 } 63} 64 65static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, 66 AVPacket *avpkt) { 67 const uint8_t *buf = avpkt->data; 68 int buf_size = avpkt->size; 69 CamStudioContext *c = avctx->priv_data; 70 int ret; 71 72 if (buf_size < 2) { 73 av_log(avctx, AV_LOG_ERROR, "coded frame too small\n"); 74 return AVERROR_INVALIDDATA; 75 } 76 77 if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) 78 return ret; 79 80 // decompress data 81 switch ((buf[0] >> 1) & 7) { 82 case 0: { // lzo compression 83 int outlen = c->decomp_size, inlen = buf_size - 2; 84 if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen)) 85 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n"); 86 break; 87 } 88 case 1: { // zlib compression 89#if CONFIG_ZLIB 90 unsigned long dlen = c->decomp_size; 91 if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK) 92 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n"); 93 break; 94#else 95 av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n"); 96 return AVERROR(ENOSYS); 97#endif 98 } 99 default: 100 av_log(avctx, AV_LOG_ERROR, "unknown compression\n"); 101 return AVERROR_INVALIDDATA; 102 } 103 104 // flip upside down, add difference frame 105 if (buf[0] & 1) { // keyframe 106 c->pic->pict_type = AV_PICTURE_TYPE_I; 107 c->pic->key_frame = 1; 108 copy_frame_default(c->pic, c->decomp_buf, 109 c->linelen, c->height); 110 } else { 111 c->pic->pict_type = AV_PICTURE_TYPE_P; 112 c->pic->key_frame = 0; 113 add_frame_default(c->pic, c->decomp_buf, 114 c->linelen, c->height); 115 } 116 117 *got_frame = 1; 118 if ((ret = av_frame_ref(data, c->pic)) < 0) 119 return ret; 120 121 return buf_size; 122} 123 124static av_cold int decode_init(AVCodecContext *avctx) { 125 CamStudioContext *c = avctx->priv_data; 126 int stride; 127 switch (avctx->bits_per_coded_sample) { 128 case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555LE; break; 129 case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break; 130 case 32: avctx->pix_fmt = AV_PIX_FMT_BGRA; break; 131 default: 132 av_log(avctx, AV_LOG_ERROR, 133 "CamStudio codec error: invalid depth %i bpp\n", 134 avctx->bits_per_coded_sample); 135 return AVERROR_INVALIDDATA; 136 } 137 c->bpp = avctx->bits_per_coded_sample; 138 c->linelen = avctx->width * avctx->bits_per_coded_sample / 8; 139 c->height = avctx->height; 140 stride = FFALIGN(c->linelen, 4); 141 c->decomp_size = c->height * stride; 142 c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING); 143 if (!c->decomp_buf) { 144 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); 145 return AVERROR(ENOMEM); 146 } 147 c->pic = av_frame_alloc(); 148 if (!c->pic) 149 return AVERROR(ENOMEM); 150 return 0; 151} 152 153static av_cold int decode_end(AVCodecContext *avctx) { 154 CamStudioContext *c = avctx->priv_data; 155 av_freep(&c->decomp_buf); 156 av_frame_free(&c->pic); 157 return 0; 158} 159 160AVCodec ff_cscd_decoder = { 161 .name = "camstudio", 162 .long_name = NULL_IF_CONFIG_SMALL("CamStudio"), 163 .type = AVMEDIA_TYPE_VIDEO, 164 .id = AV_CODEC_ID_CSCD, 165 .priv_data_size = sizeof(CamStudioContext), 166 .init = decode_init, 167 .close = decode_end, 168 .decode = decode_frame, 169 .capabilities = CODEC_CAP_DR1, 170}; 171