yading@10: /*
yading@10:  * Copyright (C) 2007  FFmpeg Project
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: 
yading@10: #include "libavutil/intreadwrite.h"
yading@10: #include "xiph.h"
yading@10: 
yading@10: int avpriv_split_xiph_headers(uint8_t *extradata, int extradata_size,
yading@10:                           int first_header_size, uint8_t *header_start[3],
yading@10:                           int header_len[3])
yading@10: {
yading@10:     int i;
yading@10: 
yading@10:     if (extradata_size >= 6 && AV_RB16(extradata) == first_header_size) {
yading@10:         int overall_len = 6;
yading@10:         for (i=0; i<3; i++) {
yading@10:             header_len[i] = AV_RB16(extradata);
yading@10:             extradata += 2;
yading@10:             header_start[i] = extradata;
yading@10:             extradata += header_len[i];
yading@10:             if (overall_len > extradata_size - header_len[i])
yading@10:                 return -1;
yading@10:             overall_len += header_len[i];
yading@10:         }
yading@10:     } else if (extradata_size >= 3 && extradata_size < INT_MAX - 0x1ff && extradata[0] == 2) {
yading@10:         int overall_len = 3;
yading@10:         extradata++;
yading@10:         for (i=0; i<2; i++, extradata++) {
yading@10:             header_len[i] = 0;
yading@10:             for (; overall_len < extradata_size && *extradata==0xff; extradata++) {
yading@10:                 header_len[i] += 0xff;
yading@10:                 overall_len   += 0xff + 1;
yading@10:             }
yading@10:             header_len[i] += *extradata;
yading@10:             overall_len   += *extradata;
yading@10:             if (overall_len > extradata_size)
yading@10:                 return -1;
yading@10:         }
yading@10:         header_len[2] = extradata_size - overall_len;
yading@10:         header_start[0] = extradata;
yading@10:         header_start[1] = header_start[0] + header_len[0];
yading@10:         header_start[2] = header_start[1] + header_len[1];
yading@10:     } else {
yading@10:         return -1;
yading@10:     }
yading@10:     return 0;
yading@10: }