blob: 10f3a2a696adbc8fc46f5815709e425df31004b8 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "media/mp4/cenc.h"
#include <cstring>
#include "media/mp4/box_reader.h"
#include "media/mp4/rcheck.h"
namespace media {
namespace mp4 {
FrameCENCInfo::FrameCENCInfo() {}
FrameCENCInfo::~FrameCENCInfo() {}
bool FrameCENCInfo::Parse(int iv_size, BufferReader* reader) {
const int kEntrySize = 6;
// Mandated by CENC spec
RCHECK(iv_size == 8 || iv_size == 16);
memset(iv, 0, sizeof(iv));
for (int i = 0; i < iv_size; i++)
RCHECK(reader->Read1(&iv[i]));
if (!reader->HasBytes(1)) return true;
uint16 subsample_count;
RCHECK(reader->Read2(&subsample_count) &&
reader->HasBytes(subsample_count * kEntrySize));
subsamples.resize(subsample_count);
for (int i = 0; i < subsample_count; i++) {
uint16 clear_bytes;
uint32 cypher_bytes;
RCHECK(reader->Read2(&clear_bytes) &&
reader->Read4(&cypher_bytes));
subsamples[i].clear_bytes = clear_bytes;
subsamples[i].cypher_bytes = cypher_bytes;
}
return true;
}
bool FrameCENCInfo::GetTotalSizeOfSubsamples(size_t* total_size) const {
size_t size = 0;
for (size_t i = 0; i < subsamples.size(); i++) {
size += subsamples[i].clear_bytes;
RCHECK(size >= subsamples[i].clear_bytes); // overflow
size += subsamples[i].cypher_bytes;
RCHECK(size >= subsamples[i].cypher_bytes); // overflow
}
*total_size = size;
return true;
}
} // namespace mp4
} // namespace media
|
