/* * CamStudio decoder * Copyright (c) 2006 Reimar Doeffinger * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <stdio.h> #include <stdlib.h> #include "avcodec.h" #include "internal.h" #include "libavutil/common.h" #if CONFIG_ZLIB #include <zlib.h> #endif #include "libavutil/lzo.h" typedef struct CamStudioContext { AVFrame *pic; int linelen, height, bpp; unsigned int decomp_size; unsigned char* decomp_buf; } CamStudioContext; static void copy_frame_default(AVFrame *f, const uint8_t *src, int linelen, int height) { int i, src_stride = FFALIGN(linelen, 4); uint8_t *dst = f->data[0]; dst += (height - 1) * f->linesize[0]; for (i = height; i; i--) { memcpy(dst, src, linelen); src += src_stride; dst -= f->linesize[0]; } } static void add_frame_default(AVFrame *f, const uint8_t *src, int linelen, int height) { int i, j, src_stride = FFALIGN(linelen, 4); uint8_t *dst = f->data[0]; dst += (height - 1) * f->linesize[0]; for (i = height; i; i--) { for (j = linelen; j; j--) *dst++ += *src++; src += src_stride - linelen; dst -= f->linesize[0] + linelen; } } static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; CamStudioContext *c = avctx->priv_data; int ret; if (buf_size < 2) { av_log(avctx, AV_LOG_ERROR, "coded frame too small\n"); return AVERROR_INVALIDDATA; } if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) return ret; // decompress data switch ((buf[0] >> 1) & 7) { case 0: { // lzo compression int outlen = c->decomp_size, inlen = buf_size - 2; if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen)) av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n"); break; } case 1: { // zlib compression #if CONFIG_ZLIB unsigned long dlen = c->decomp_size; if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK) av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n"); break; #else av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n"); return AVERROR(ENOSYS); #endif } default: av_log(avctx, AV_LOG_ERROR, "unknown compression\n"); return AVERROR_INVALIDDATA; } // flip upside down, add difference frame if (buf[0] & 1) { // keyframe c->pic->pict_type = AV_PICTURE_TYPE_I; c->pic->key_frame = 1; copy_frame_default(c->pic, c->decomp_buf, c->linelen, c->height); } else { c->pic->pict_type = AV_PICTURE_TYPE_P; c->pic->key_frame = 0; add_frame_default(c->pic, c->decomp_buf, c->linelen, c->height); } *got_frame = 1; if ((ret = av_frame_ref(data, c->pic)) < 0) return ret; return buf_size; } static av_cold int decode_init(AVCodecContext *avctx) { CamStudioContext *c = avctx->priv_data; int stride; switch (avctx->bits_per_coded_sample) { case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555LE; break; case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break; case 32: avctx->pix_fmt = AV_PIX_FMT_BGR0; break; default: av_log(avctx, AV_LOG_ERROR, "CamStudio codec error: invalid depth %i bpp\n", avctx->bits_per_coded_sample); return AVERROR_INVALIDDATA; } c->bpp = avctx->bits_per_coded_sample; c->linelen = avctx->width * avctx->bits_per_coded_sample / 8; c->height = avctx->height; stride = FFALIGN(c->linelen, 4); c->decomp_size = c->height * stride; c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING); if (!c->decomp_buf) { av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n"); return AVERROR(ENOMEM); } c->pic = av_frame_alloc(); if (!c->pic) return AVERROR(ENOMEM); return 0; } static av_cold int decode_end(AVCodecContext *avctx) { CamStudioContext *c = avctx->priv_data; av_freep(&c->decomp_buf); av_frame_free(&c->pic); return 0; } AVCodec ff_cscd_decoder = { .name = "camstudio", .long_name = NULL_IF_CONFIG_SMALL("CamStudio"), .type = AVMEDIA_TYPE_VIDEO, .id = AV_CODEC_ID_CSCD, .priv_data_size = sizeof(CamStudioContext), .init = decode_init, .close = decode_end, .decode = decode_frame, .capabilities = AV_CODEC_CAP_DR1, };