FFmpeg
xiph.c
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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 <limits.h>
22 #include "libavutil/error.h"
23 #include "libavutil/intreadwrite.h"
24 #include "xiph.h"
25 
26 int avpriv_split_xiph_headers(const uint8_t *extradata, int extradata_size,
27  int first_header_size, const uint8_t *header_start[3],
28  int header_len[3])
29 {
30  int i;
31 
32  if (extradata_size >= 6 && AV_RB16(extradata) == first_header_size) {
33  int overall_len = 6;
34  for (i=0; i<3; i++) {
35  header_len[i] = AV_RB16(extradata);
36  extradata += 2;
37  header_start[i] = extradata;
38  extradata += header_len[i];
39  if (overall_len > extradata_size - header_len[i])
40  return AVERROR_INVALIDDATA;
41  overall_len += header_len[i];
42  }
43  } else if (extradata_size >= 3 && extradata_size < INT_MAX - 0x1ff && extradata[0] == 2) {
44  int overall_len = 3;
45  extradata++;
46  for (i=0; i<2; i++, extradata++) {
47  header_len[i] = 0;
48  for (; overall_len < extradata_size && *extradata==0xff; extradata++) {
49  header_len[i] += 0xff;
50  overall_len += 0xff + 1;
51  }
52  header_len[i] += *extradata;
53  overall_len += *extradata;
54  if (overall_len > extradata_size)
55  return AVERROR_INVALIDDATA;
56  }
57  header_len[2] = extradata_size - overall_len;
58  header_start[0] = extradata;
59  header_start[1] = header_start[0] + header_len[0];
60  header_start[2] = header_start[1] + header_len[1];
61  } else {
62  return -1;
63  }
64  return 0;
65 }
xiph.h
intreadwrite.h
limits.h
error.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
avpriv_split_xiph_headers
int avpriv_split_xiph_headers(const uint8_t *extradata, int extradata_size, int first_header_size, const uint8_t *header_start[3], int header_len[3])
Split a single extradata buffer into the three headers that most Xiph codecs use.
Definition: xiph.c:26
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AV_RB16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:98