yading@10: /*
yading@10:  * CamStudio decoder
yading@10:  * Copyright (c) 2006 Reimar Doeffinger
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: #include <stdio.h>
yading@10: #include <stdlib.h>
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "internal.h"
yading@10: #include "libavutil/common.h"
yading@10: 
yading@10: #if CONFIG_ZLIB
yading@10: #include <zlib.h>
yading@10: #endif
yading@10: #include "libavutil/lzo.h"
yading@10: 
yading@10: typedef struct {
yading@10:     AVFrame *pic;
yading@10:     int linelen, height, bpp;
yading@10:     unsigned int decomp_size;
yading@10:     unsigned char* decomp_buf;
yading@10: } CamStudioContext;
yading@10: 
yading@10: static void copy_frame_default(AVFrame *f, const uint8_t *src,
yading@10:                                int linelen, int height) {
yading@10:     int i, src_stride = FFALIGN(linelen, 4);
yading@10:     uint8_t *dst = f->data[0];
yading@10:     dst += (height - 1) * f->linesize[0];
yading@10:     for (i = height; i; i--) {
yading@10:         memcpy(dst, src, linelen);
yading@10:         src += src_stride;
yading@10:         dst -= f->linesize[0];
yading@10:     }
yading@10: }
yading@10: 
yading@10: static void add_frame_default(AVFrame *f, const uint8_t *src,
yading@10:                               int linelen, int height) {
yading@10:     int i, j, src_stride = FFALIGN(linelen, 4);
yading@10:     uint8_t *dst = f->data[0];
yading@10:     dst += (height - 1) * f->linesize[0];
yading@10:     for (i = height; i; i--) {
yading@10:         for (j = linelen; j; j--)
yading@10:             *dst++ += *src++;
yading@10:         src += src_stride - linelen;
yading@10:         dst -= f->linesize[0] + linelen;
yading@10:     }
yading@10: }
yading@10: 
yading@10: static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
yading@10:                         AVPacket *avpkt) {
yading@10:     const uint8_t *buf = avpkt->data;
yading@10:     int buf_size = avpkt->size;
yading@10:     CamStudioContext *c = avctx->priv_data;
yading@10:     int ret;
yading@10: 
yading@10:     if (buf_size < 2) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     if ((ret = ff_reget_buffer(avctx, c->pic)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     // decompress data
yading@10:     switch ((buf[0] >> 1) & 7) {
yading@10:         case 0: { // lzo compression
yading@10:             int outlen = c->decomp_size, inlen = buf_size - 2;
yading@10:             if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen))
yading@10:                 av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
yading@10:             break;
yading@10:         }
yading@10:         case 1: { // zlib compression
yading@10: #if CONFIG_ZLIB
yading@10:             unsigned long dlen = c->decomp_size;
yading@10:             if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK)
yading@10:                 av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
yading@10:             break;
yading@10: #else
yading@10:             av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
yading@10:             return AVERROR(ENOSYS);
yading@10: #endif
yading@10:         }
yading@10:         default:
yading@10:             av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
yading@10:             return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     // flip upside down, add difference frame
yading@10:     if (buf[0] & 1) { // keyframe
yading@10:         c->pic->pict_type = AV_PICTURE_TYPE_I;
yading@10:         c->pic->key_frame = 1;
yading@10:               copy_frame_default(c->pic, c->decomp_buf,
yading@10:                                  c->linelen, c->height);
yading@10:     } else {
yading@10:         c->pic->pict_type = AV_PICTURE_TYPE_P;
yading@10:         c->pic->key_frame = 0;
yading@10:               add_frame_default(c->pic, c->decomp_buf,
yading@10:                                 c->linelen, c->height);
yading@10:     }
yading@10: 
yading@10:     *got_frame = 1;
yading@10:     if ((ret = av_frame_ref(data, c->pic)) < 0)
yading@10:         return ret;
yading@10: 
yading@10:     return buf_size;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_init(AVCodecContext *avctx) {
yading@10:     CamStudioContext *c = avctx->priv_data;
yading@10:     int stride;
yading@10:     switch (avctx->bits_per_coded_sample) {
yading@10:         case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555LE; break;
yading@10:         case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
yading@10:         case 32: avctx->pix_fmt = AV_PIX_FMT_BGRA; break;
yading@10:         default:
yading@10:             av_log(avctx, AV_LOG_ERROR,
yading@10:                    "CamStudio codec error: invalid depth %i bpp\n",
yading@10:                    avctx->bits_per_coded_sample);
yading@10:             return AVERROR_INVALIDDATA;
yading@10:     }
yading@10:     c->bpp = avctx->bits_per_coded_sample;
yading@10:     c->linelen = avctx->width * avctx->bits_per_coded_sample / 8;
yading@10:     c->height = avctx->height;
yading@10:     stride = FFALIGN(c->linelen, 4);
yading@10:     c->decomp_size = c->height * stride;
yading@10:     c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING);
yading@10:     if (!c->decomp_buf) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
yading@10:         return AVERROR(ENOMEM);
yading@10:     }
yading@10:     c->pic = av_frame_alloc();
yading@10:     if (!c->pic)
yading@10:         return AVERROR(ENOMEM);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold int decode_end(AVCodecContext *avctx) {
yading@10:     CamStudioContext *c = avctx->priv_data;
yading@10:     av_freep(&c->decomp_buf);
yading@10:     av_frame_free(&c->pic);
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_cscd_decoder = {
yading@10:     .name           = "camstudio",
yading@10:     .type           = AVMEDIA_TYPE_VIDEO,
yading@10:     .id             = AV_CODEC_ID_CSCD,
yading@10:     .priv_data_size = sizeof(CamStudioContext),
yading@10:     .init           = decode_init,
yading@10:     .close          = decode_end,
yading@10:     .decode         = decode_frame,
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("CamStudio"),
yading@10: };