| 1 | /* |
| 2 | * Copyright (C) 2007 The 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 | |
| 24 | int avpriv_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 | } |