1 // Copyright 2015 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef MEDIA_FORMATS_MP2T_DESCRIPTORS_H_
6 #define MEDIA_FORMATS_MP2T_DESCRIPTORS_H_
7 
8 #include <stdint.h>
9 
10 #include <map>
11 #include <string>
12 
13 #include "media/base/decrypt_config.h"
14 
15 namespace media {
16 
17 class BitReader;
18 
19 namespace mp2t {
20 
21 // Representation of a list of descriptors, used in the MPEG-2 Systems standard
22 // to extend the definitions of programs or program elements. While the standard
23 // appears to permit multiple descriptors in such a list to have the same tag
24 // value, the implementation herein will not support this.
25 class Descriptors {
26  public:
27   Descriptors();
28   Descriptors(const Descriptors& other);
29   ~Descriptors();
30 
31   // Attempts to read a (possibly empty) list of descriptors from the |reader|.
32   // If |size| > 0, the descriptors must occupy exactly |size| bytes, Otherwise,
33   // the descriptors should use all available bits from the reader.
34   bool Read(BitReader* reader, int size);
35 
36   // Indicates whether a Registration descriptor is present. If so, the
37   // |format_identifier| and |additional_info| values are populated with the
38   // contents of the descriptor.
39   bool HasRegistrationDescriptor(int64_t* format_identifier,
40                                  std::string* additional_info) const;
41 
42   // Indicates whether a CA descriptor is present. If so, the |system_id|,
43   // |pid|, and |private_data| values are populated with the contents of the
44   // descriptor.
45   bool HasCADescriptor(int* system_id,
46                        int* pid,
47                        std::string* private_data) const;
48 
49   // Indicates whether a CA descriptor is present, and if so, whether it is
50   // of the type defined by ISO/IEC 23001-9:2014 (i.e. with a specific
51   // system_id value and layout of the private_data). If so, the |ca_pid|,
52   // |pssh_pid| and |mode| are populated with the contents of the descriptor.
53   bool HasCADescriptorCenc(int* ca_pid,
54                            int* pssh_pid,
55                            EncryptionScheme* scheme) const;
56 
57   // Indicates whether a Private Data Indicator descriptor is present with a
58   // particular |value|.
59   bool HasPrivateDataIndicator(int64_t value) const;
60 
61  private:
62   using Descriptor = std::pair<int, std::string>;
63   std::map<int, std::string> descriptors_;
64 
65   // Allow copy and assign so that it can be used in a std C++ container.
66 };
67 
68 }  // namespace mp2t
69 }  // namespace media
70 
71 #endif  // MEDIA_FORMATS_MP2T_DESCRIPTOR_LIST_H_
72