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/*
* 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 "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
#include "libavutil/mem.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, AVFrame *rframe,
int *got_frame, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
CamStudioContext *c = avctx->priv_data;
int ret;
int bpp = avctx->bits_per_coded_sample / 8;
int bugdelta = FFALIGN(avctx->width * bpp, 4) * avctx->height
- (avctx->width & ~3) * bpp * avctx->height;
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)) < 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) || (outlen && outlen != bugdelta)) {
av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
return AVERROR_INVALIDDATA;
}
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 || (dlen != c->decomp_size && dlen != c->decomp_size - bugdelta)) {
av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
return AVERROR_INVALIDDATA;
}
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->flags |= AV_FRAME_FLAG_KEY;
copy_frame_default(c->pic, c->decomp_buf,
c->linelen, c->height);
} else {
c->pic->pict_type = AV_PICTURE_TYPE_P;
c->pic->flags &= ~AV_FRAME_FLAG_KEY;
add_frame_default(c->pic, c->decomp_buf,
c->linelen, c->height);
}
*got_frame = 1;
if ((ret = av_frame_ref(rframe, 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;
}
const FFCodec ff_cscd_decoder = {
.p.name = "camstudio",
CODEC_LONG_NAME("CamStudio"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_CSCD,
.priv_data_size = sizeof(CamStudioContext),
.init = decode_init,
.close = decode_end,
FF_CODEC_DECODE_CB(decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};
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