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#include <utility>
10
11#include "base/logging.h"
12#include "base/memory/aligned_memory.h"
13#include "base/memory/ref_counted.h"
14#include "base/memory/scoped_ptr.h"
15#include "base/time/time.h"
16#include "build/build_config.h"
17#include "media/base/decrypt_config.h"
18#include "media/base/media_export.h"
19
20namespace media {
21
22// A specialized buffer for interfacing with audio / video decoders.
23//
24// Specifically ensures that data is aligned and padded as necessary by the
25// underlying decoding framework.  On desktop platforms this means memory is
26// allocated using FFmpeg with particular alignment and padding requirements.
27//
28// Also includes decoder specific functionality for decryption.
29//
30// NOTE: It is illegal to call any method when end_of_stream() is true.
31class MEDIA_EXPORT DecoderBuffer
32    : public base::RefCountedThreadSafe<DecoderBuffer> {
33 public:
34  enum {
35    kPaddingSize = 16,
36#if defined(ARCH_CPU_ARM_FAMILY)
37    kAlignmentSize = 16
38#else
39    kAlignmentSize = 32
40#endif
41  };
42
43  // Allocates buffer with |size| >= 0.  Buffer will be padded and aligned
44  // as necessary.
45  explicit DecoderBuffer(int size);
46
47  // Create a DecoderBuffer whose |data_| is copied from |data|.  Buffer will be
48  // padded and aligned as necessary.  |data| must not be NULL and |size| >= 0.
49  static scoped_refptr<DecoderBuffer> CopyFrom(const uint8* data, int size);
50
51  // Create a DecoderBuffer whose |data_| is copied from |data| and |side_data_|
52  // is copied from |side_data|. Buffers will be padded and aligned as necessary
53  // Data pointers must not be NULL and sizes must be >= 0.
54  static scoped_refptr<DecoderBuffer> CopyFrom(const uint8* data, int size,
55                                               const uint8* side_data,
56                                               int side_data_size);
57
58  // Create a DecoderBuffer indicating we've reached end of stream.
59  //
60  // Calling any method other than end_of_stream() on the resulting buffer
61  // is disallowed.
62  static scoped_refptr<DecoderBuffer> CreateEOSBuffer();
63
64  base::TimeDelta timestamp() const {
65    DCHECK(!end_of_stream());
66    return timestamp_;
67  }
68
69  // TODO(dalecurtis): This should be renamed at some point, but to avoid a yak
70  // shave keep as a virtual with hacker_style() for now.
71  virtual void set_timestamp(base::TimeDelta timestamp);
72
73  base::TimeDelta duration() const {
74    DCHECK(!end_of_stream());
75    return duration_;
76  }
77
78  void set_duration(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  // A discard window indicates the amount of data which should be discard from
109  // this buffer after decoding.  The first value is the amount of the front and
110  // the second the amount off the back.  A value of kInfiniteDuration() for the
111  // first value indicates the entire buffer should be discarded; the second
112  // value must be base::TimeDelta() in this case.
113  typedef std::pair<base::TimeDelta, base::TimeDelta> DiscardPadding;
114  const DiscardPadding& discard_padding() const {
115    DCHECK(!end_of_stream());
116    return discard_padding_;
117  }
118
119  void set_discard_padding(const DiscardPadding& discard_padding) {
120    DCHECK(!end_of_stream());
121    discard_padding_ = discard_padding;
122  }
123
124  const DecryptConfig* decrypt_config() const {
125    DCHECK(!end_of_stream());
126    return decrypt_config_.get();
127  }
128
129  void set_decrypt_config(scoped_ptr<DecryptConfig> decrypt_config) {
130    DCHECK(!end_of_stream());
131    decrypt_config_ = decrypt_config.Pass();
132  }
133
134  // If there's no data in this buffer, it represents end of stream.
135  bool end_of_stream() const {
136    return data_ == NULL;
137  }
138
139  // Indicates this buffer is part of a splice around |splice_timestamp_|.
140  // Returns kNoTimestamp() if the buffer is not part of a splice.
141  base::TimeDelta splice_timestamp() const {
142    DCHECK(!end_of_stream());
143    return splice_timestamp_;
144  }
145
146  // When set to anything but kNoTimestamp() indicates this buffer is part of a
147  // splice around |splice_timestamp|.
148  void set_splice_timestamp(base::TimeDelta splice_timestamp) {
149    DCHECK(!end_of_stream());
150    splice_timestamp_ = splice_timestamp;
151  }
152
153  // Returns a human-readable string describing |*this|.
154  std::string AsHumanReadableString();
155
156 protected:
157  friend class base::RefCountedThreadSafe<DecoderBuffer>;
158
159  // Allocates a buffer of size |size| >= 0 and copies |data| into it.  Buffer
160  // will be padded and aligned as necessary.  If |data| is NULL then |data_| is
161  // set to NULL and |buffer_size_| to 0.
162  DecoderBuffer(const uint8* data, int size,
163                const uint8* side_data, int side_data_size);
164  virtual ~DecoderBuffer();
165
166 private:
167  base::TimeDelta timestamp_;
168  base::TimeDelta duration_;
169
170  int size_;
171  scoped_ptr<uint8, base::AlignedFreeDeleter> data_;
172  int side_data_size_;
173  scoped_ptr<uint8, base::AlignedFreeDeleter> side_data_;
174  scoped_ptr<DecryptConfig> decrypt_config_;
175  DiscardPadding discard_padding_;
176  base::TimeDelta splice_timestamp_;
177
178  // Constructor helper method for memory allocations.
179  void Initialize();
180
181  DISALLOW_COPY_AND_ASSIGN(DecoderBuffer);
182};
183
184}  // namespace media
185
186#endif  // MEDIA_BASE_DECODER_BUFFER_H_
187