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ffmpeg / libavcodec / xiph.c @ 2912e87a

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/*
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 * Copyright (C) 2007  Libav Project
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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 "libavutil/intreadwrite.h"
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#include "xiph.h"
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int ff_split_xiph_headers(uint8_t *extradata, int extradata_size,
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                          int first_header_size, uint8_t *header_start[3],
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                          int header_len[3])
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{
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    int i;
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    if (extradata_size >= 6 && AV_RB16(extradata) == first_header_size) {
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        int overall_len = 6;
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        for (i=0; i<3; i++) {
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            header_len[i] = AV_RB16(extradata);
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            extradata += 2;
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            header_start[i] = extradata;
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            extradata += header_len[i];
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            if (overall_len > extradata_size - header_len[i])
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                return -1;
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            overall_len += header_len[i];
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        }
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    } else if (extradata_size >= 3 && extradata_size < INT_MAX - 0x1ff && extradata[0] == 2) {
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        int overall_len = 3;
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        extradata++;
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        for (i=0; i<2; i++, extradata++) {
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            header_len[i] = 0;
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            for (; overall_len < extradata_size && *extradata==0xff; extradata++) {
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                header_len[i] += 0xff;
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                overall_len   += 0xff + 1;
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            }
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            header_len[i] += *extradata;
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            overall_len   += *extradata;
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            if (overall_len > extradata_size)
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                return -1;
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        }
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        header_len[2] = extradata_size - overall_len;
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        header_start[0] = extradata;
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        header_start[1] = header_start[0] + header_len[0];
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        header_start[2] = header_start[1] + header_len[1];
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    } else {
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        return -1;
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    }
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    return 0;
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}