1/* 2 * Copyright (C) 2007 FFmpeg Project 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21#include "libavutil/intreadwrite.h" 22#include "xiph.h" 23 24int ff_split_xiph_headers(uint8_t *extradata, int extradata_size, 25 int first_header_size, uint8_t *header_start[3], 26 int header_len[3]) 27{ 28 int i; 29 30 if (extradata_size >= 6 && AV_RB16(extradata) == first_header_size) { 31 int overall_len = 6; 32 for (i=0; i<3; i++) { 33 header_len[i] = AV_RB16(extradata); 34 extradata += 2; 35 header_start[i] = extradata; 36 extradata += header_len[i]; 37 if (overall_len > extradata_size - header_len[i]) 38 return -1; 39 overall_len += header_len[i]; 40 } 41 } else if (extradata_size >= 3 && extradata_size < INT_MAX - 0x1ff && extradata[0] == 2) { 42 int overall_len = 3; 43 extradata++; 44 for (i=0; i<2; i++, extradata++) { 45 header_len[i] = 0; 46 for (; overall_len < extradata_size && *extradata==0xff; extradata++) { 47 header_len[i] += 0xff; 48 overall_len += 0xff + 1; 49 } 50 header_len[i] += *extradata; 51 overall_len += *extradata; 52 if (overall_len > extradata_size) 53 return -1; 54 } 55 header_len[2] = extradata_size - overall_len; 56 header_start[0] = extradata; 57 header_start[1] = header_start[0] + header_len[0]; 58 header_start[2] = header_start[1] + header_len[1]; 59 } else { 60 return -1; 61 } 62 return 0; 63} 64