/* * 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,};