ffmpeg/libavcodec/xiph.c

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