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/*
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 * CamStudio decoder
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 * Copyright (c) 2006 Reimar Doeffinger
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include <stdio.h>
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#include <stdlib.h>
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#include "avcodec.h"
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#if CONFIG_ZLIB
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#include <zlib.h>
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#endif
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#include "libavutil/lzo.h"
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typedef struct {
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    AVFrame pic;
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    int linelen, height, bpp;
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    unsigned int decomp_size;
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    unsigned char* decomp_buf;
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} CamStudioContext;
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static void copy_frame_default(AVFrame *f, const uint8_t *src, int src_stride,
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                               int linelen, int height) {
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    int i;
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    uint8_t *dst = f->data[0];
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    dst += (height - 1) * f->linesize[0];
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    for (i = height; i; i--) {
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        memcpy(dst, src, linelen);
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        src += src_stride;
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        dst -= f->linesize[0];
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    }
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}
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static void add_frame_default(AVFrame *f, const uint8_t *src, int src_stride,
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                              int linelen, int height) {
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    int i, j;
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    uint8_t *dst = f->data[0];
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    dst += (height - 1) * f->linesize[0];
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    for (i = height; i; i--) {
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        for (j = linelen; j; j--)
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            *dst++ += *src++;
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        src += src_stride - linelen;
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        dst -= f->linesize[0] + linelen;
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    }
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}
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#if !HAVE_BIGENDIAN
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#define copy_frame_16(f, s, l, h) copy_frame_default(f, s, l, l, h)
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#define copy_frame_32(f, s, l, h) copy_frame_default(f, s, l, l, h)
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#define add_frame_16(f, s, l, h) add_frame_default(f, s, l, l, h)
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#define add_frame_32(f, s, l, h) add_frame_default(f, s, l, l, h)
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#else
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static void copy_frame_16(AVFrame *f, const uint8_t *src,
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                          int linelen, int height) {
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    int i, j;
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    uint8_t *dst = f->data[0];
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    dst += (height - 1) * f->linesize[0];
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    for (i = height; i; i--) {
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        for (j = linelen / 2; j; j--) {
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          dst[0] = src[1];
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          dst[1] = src[0];
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          src += 2;
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          dst += 2;
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        }
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        dst -= f->linesize[0] + linelen;
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    }
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}
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static void copy_frame_32(AVFrame *f, const uint8_t *src,
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                          int linelen, int height) {
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    int i, j;
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    uint8_t *dst = f->data[0];
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    dst += (height - 1) * f->linesize[0];
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    for (i = height; i; i--) {
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        for (j = linelen / 4; j; j--) {
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          dst[0] = src[3];
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          dst[1] = src[2];
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          dst[2] = src[1];
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          dst[3] = src[0];
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          src += 4;
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          dst += 4;
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        }
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        dst -= f->linesize[0] + linelen;
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    }
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}
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static void add_frame_16(AVFrame *f, const uint8_t *src,
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                         int linelen, int height) {
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    int i, j;
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    uint8_t *dst = f->data[0];
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    dst += (height - 1) * f->linesize[0];
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    for (i = height; i; i--) {
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        for (j = linelen / 2; j; j--) {
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          dst[0] += src[1];
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          dst[1] += src[0];
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          src += 2;
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          dst += 2;
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        }
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        dst -= f->linesize[0] + linelen;
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    }
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}
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static void add_frame_32(AVFrame *f, const uint8_t *src,
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                         int linelen, int height) {
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    int i, j;
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    uint8_t *dst = f->data[0];
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    dst += (height - 1) * f->linesize[0];
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    for (i = height; i; i--) {
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        for (j = linelen / 4; j; j--) {
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          dst[0] += src[3];
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          dst[1] += src[2];
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          dst[2] += src[1];
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          dst[3] += src[0];
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          src += 4;
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          dst += 4;
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        }
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        dst -= f->linesize[0] + linelen;
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    }
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}
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#endif
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static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
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                        AVPacket *avpkt) {
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    const uint8_t *buf = avpkt->data;
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    int buf_size = avpkt->size;
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    CamStudioContext *c = avctx->priv_data;
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    AVFrame *picture = data;
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    if (buf_size < 2) {
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        av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
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        return -1;
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    }
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    if (c->pic.data[0])
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        avctx->release_buffer(avctx, &c->pic);
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    c->pic.reference = 1;
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    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE |
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                          FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
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    if (avctx->get_buffer(avctx, &c->pic) < 0) {
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        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
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        return -1;
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    }
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    // decompress data
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    switch ((buf[0] >> 1) & 7) {
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        case 0: { // lzo compression
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            int outlen = c->decomp_size, inlen = buf_size - 2;
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            if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen))
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                av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
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            break;
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        }
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        case 1: { // zlib compression
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#if CONFIG_ZLIB
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            unsigned long dlen = c->decomp_size;
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            if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK)
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                av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
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            break;
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#else
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            av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
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            return -1;
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#endif
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        }
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        default:
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            av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
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            return -1;
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    }
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    // flip upside down, add difference frame
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    if (buf[0] & 1) { // keyframe
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        c->pic.pict_type = FF_I_TYPE;
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        c->pic.key_frame = 1;
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        switch (c->bpp) {
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          case 16:
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              copy_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
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              break;
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          case 32:
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              copy_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
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              break;
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          default:
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              copy_frame_default(&c->pic, c->decomp_buf, FFALIGN(c->linelen, 4),
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                                 c->linelen, c->height);
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        }
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    } else {
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        c->pic.pict_type = FF_P_TYPE;
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        c->pic.key_frame = 0;
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        switch (c->bpp) {
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          case 16:
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              add_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
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              break;
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          case 32:
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              add_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
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              break;
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          default:
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              add_frame_default(&c->pic, c->decomp_buf, FFALIGN(c->linelen, 4),
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                                c->linelen, c->height);
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        }
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    }
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    *picture = c->pic;
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    *data_size = sizeof(AVFrame);
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    return buf_size;
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}
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static av_cold int decode_init(AVCodecContext *avctx) {
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    CamStudioContext *c = avctx->priv_data;
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    int stride;
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    switch (avctx->bits_per_coded_sample) {
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        case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
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        case 24: avctx->pix_fmt = PIX_FMT_BGR24; break;
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        case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
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        default:
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            av_log(avctx, AV_LOG_ERROR,
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                   "CamStudio codec error: invalid depth %i bpp\n",
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                   avctx->bits_per_coded_sample);
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            return 1;
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    }
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    c->bpp = avctx->bits_per_coded_sample;
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    c->pic.data[0] = NULL;
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    c->linelen = avctx->width * avctx->bits_per_coded_sample / 8;
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    c->height = avctx->height;
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    stride = c->linelen;
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    if (avctx->bits_per_coded_sample == 24)
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        stride = FFALIGN(stride, 4);
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    c->decomp_size = c->height * stride;
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    c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING);
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    if (!c->decomp_buf) {
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        av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
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        return 1;
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    }
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    return 0;
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}
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static av_cold int decode_end(AVCodecContext *avctx) {
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    CamStudioContext *c = avctx->priv_data;
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    av_freep(&c->decomp_buf);
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    if (c->pic.data[0])
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        avctx->release_buffer(avctx, &c->pic);
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    return 0;
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}
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AVCodec ff_cscd_decoder = {
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    "camstudio",
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    AVMEDIA_TYPE_VIDEO,
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    CODEC_ID_CSCD,
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    sizeof(CamStudioContext),
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    decode_init,
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    NULL,
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    decode_end,
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    decode_frame,
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    CODEC_CAP_DR1,
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    .long_name = NULL_IF_CONFIG_SMALL("CamStudio"),
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};
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