1// Copyright (c) 2012 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_BASE_DECODER_BUFFER_H_
6#define MEDIA_BASE_DECODER_BUFFER_H_
7
8#include <string>
9
10#include "base/logging.h"
11#include "base/memory/aligned_memory.h"
12#include "base/memory/ref_counted.h"
13#include "base/memory/scoped_ptr.h"
14#include "base/time/time.h"
15#include "build/build_config.h"
16#include "media/base/decrypt_config.h"
17#include "media/base/media_export.h"
18
19namespace media {
20
21// A specialized buffer for interfacing with audio / video decoders.
22//
23// Specifically ensures that data is aligned and padded as necessary by the
24// underlying decoding framework.  On desktop platforms this means memory is
25// allocated using FFmpeg with particular alignment and padding requirements.
26//
27// Also includes decoder specific functionality for decryption.
28//
29// NOTE: It is illegal to call any method when end_of_stream() is true.
30class MEDIA_EXPORT DecoderBuffer
31    : public base::RefCountedThreadSafe<DecoderBuffer> {
32 public:
33  enum {
34    kPaddingSize = 16,
35#if defined(ARCH_CPU_ARM_FAMILY)
36    kAlignmentSize = 16
37#else
38    kAlignmentSize = 32
39#endif
40  };
41
42  // Allocates buffer with |size| >= 0.  Buffer will be padded and aligned
43  // as necessary.
44  explicit DecoderBuffer(int size);
45
46  // Create a DecoderBuffer whose |data_| is copied from |data|.  Buffer will be
47  // padded and aligned as necessary.  |data| must not be NULL and |size| >= 0.
48  static scoped_refptr<DecoderBuffer> CopyFrom(const uint8* data, int size);
49
50  // Create a DecoderBuffer whose |data_| is copied from |data| and |side_data_|
51  // is copied from |side_data|. Buffers will be padded and aligned as necessary
52  // Data pointers must not be NULL and sizes must be >= 0.
53  static scoped_refptr<DecoderBuffer> CopyFrom(const uint8* data, int size,
54                                               const uint8* side_data,
55                                               int side_data_size);
56
57  // Create a DecoderBuffer indicating we've reached end of stream.
58  //
59  // Calling any method other than end_of_stream() on the resulting buffer
60  // is disallowed.
61  static scoped_refptr<DecoderBuffer> CreateEOSBuffer();
62
63  base::TimeDelta timestamp() const {
64    DCHECK(!end_of_stream());
65    return timestamp_;
66  }
67
68  void set_timestamp(const base::TimeDelta& timestamp) {
69    DCHECK(!end_of_stream());
70    timestamp_ = timestamp;
71  }
72
73  base::TimeDelta duration() const {
74    DCHECK(!end_of_stream());
75    return duration_;
76  }
77
78  void set_duration(const base::TimeDelta& duration) {
79    DCHECK(!end_of_stream());
80    duration_ = duration;
81  }
82
83  const uint8* data() const {
84    DCHECK(!end_of_stream());
85    return data_.get();
86  }
87
88  uint8* writable_data() const {
89    DCHECK(!end_of_stream());
90    return data_.get();
91  }
92
93  int data_size() const {
94    DCHECK(!end_of_stream());
95    return size_;
96  }
97
98  const uint8* side_data() const {
99    DCHECK(!end_of_stream());
100    return side_data_.get();
101  }
102
103  int side_data_size() const {
104    DCHECK(!end_of_stream());
105    return side_data_size_;
106  }
107
108  base::TimeDelta discard_padding() const {
109    DCHECK(!end_of_stream());
110    return discard_padding_;
111  }
112
113  void set_discard_padding(const base::TimeDelta discard_padding) {
114    DCHECK(!end_of_stream());
115    discard_padding_ = discard_padding;
116  }
117
118  const DecryptConfig* decrypt_config() const {
119    DCHECK(!end_of_stream());
120    return decrypt_config_.get();
121  }
122
123  void set_decrypt_config(scoped_ptr<DecryptConfig> decrypt_config) {
124    DCHECK(!end_of_stream());
125    decrypt_config_ = decrypt_config.Pass();
126  }
127
128  // If there's no data in this buffer, it represents end of stream.
129  bool end_of_stream() const {
130    return data_ == NULL;
131  }
132
133  // Returns a human-readable string describing |*this|.
134  std::string AsHumanReadableString();
135
136 protected:
137  friend class base::RefCountedThreadSafe<DecoderBuffer>;
138
139  // Allocates a buffer of size |size| >= 0 and copies |data| into it.  Buffer
140  // will be padded and aligned as necessary.  If |data| is NULL then |data_| is
141  // set to NULL and |buffer_size_| to 0.
142  DecoderBuffer(const uint8* data, int size,
143                const uint8* side_data, int side_data_size);
144  virtual ~DecoderBuffer();
145
146 private:
147  base::TimeDelta timestamp_;
148  base::TimeDelta duration_;
149
150  int size_;
151  scoped_ptr<uint8, base::ScopedPtrAlignedFree> data_;
152  int side_data_size_;
153  scoped_ptr<uint8, base::ScopedPtrAlignedFree> side_data_;
154  scoped_ptr<DecryptConfig> decrypt_config_;
155  base::TimeDelta discard_padding_;
156
157  // Constructor helper method for memory allocations.
158  void Initialize();
159
160  DISALLOW_COPY_AND_ASSIGN(DecoderBuffer);
161};
162
163}  // namespace media
164
165#endif  // MEDIA_BASE_DECODER_BUFFER_H_
166