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/buffers.h"
18#include "media/base/decrypt_config.h"
19#include "media/base/media_export.h"
20
21namespace media {
22
23// A specialized buffer for interfacing with audio / video decoders.
24//
25// Specifically ensures that data is aligned and padded as necessary by the
26// underlying decoding framework.  On desktop platforms this means memory is
27// allocated using FFmpeg with particular alignment and padding requirements.
28//
29// Also includes decoder specific functionality for decryption.
30//
31// NOTE: It is illegal to call any method when end_of_stream() is true.
32class MEDIA_EXPORT DecoderBuffer
33    : public base::RefCountedThreadSafe<DecoderBuffer> {
34 public:
35  enum {
36    kPaddingSize = 32,
37#if defined(ARCH_CPU_ARM_FAMILY)
38    kAlignmentSize = 16
39#else
40    kAlignmentSize = 32
41#endif
42  };
43
44  // Allocates buffer with |size| >= 0.  Buffer will be padded and aligned
45  // as necessary.
46  explicit DecoderBuffer(int size);
47
48  // Create a DecoderBuffer whose |data_| is copied from |data|.  Buffer will be
49  // padded and aligned as necessary.  |data| must not be NULL and |size| >= 0.
50  static scoped_refptr<DecoderBuffer> CopyFrom(const uint8* data, int size);
51
52  // Create a DecoderBuffer whose |data_| is copied from |data| and |side_data_|
53  // is copied from |side_data|. Buffers will be padded and aligned as necessary
54  // Data pointers must not be NULL and sizes must be >= 0.
55  static scoped_refptr<DecoderBuffer> CopyFrom(const uint8* data, int size,
56                                               const uint8* side_data,
57                                               int side_data_size);
58
59  // Create a DecoderBuffer indicating we've reached end of stream.
60  //
61  // Calling any method other than end_of_stream() on the resulting buffer
62  // is disallowed.
63  static scoped_refptr<DecoderBuffer> CreateEOSBuffer();
64
65  base::TimeDelta timestamp() const {
66    DCHECK(!end_of_stream());
67    return timestamp_;
68  }
69
70  // TODO(dalecurtis): This should be renamed at some point, but to avoid a yak
71  // shave keep as a virtual with hacker_style() for now.
72  virtual void set_timestamp(base::TimeDelta timestamp);
73
74  base::TimeDelta duration() const {
75    DCHECK(!end_of_stream());
76    return duration_;
77  }
78
79  void set_duration(base::TimeDelta duration) {
80    DCHECK(!end_of_stream());
81    DCHECK(duration == kNoTimestamp() ||
82           (duration >= base::TimeDelta() && duration != kInfiniteDuration()))
83        << duration.InSecondsF();
84    duration_ = duration;
85  }
86
87  const uint8* data() const {
88    DCHECK(!end_of_stream());
89    return data_.get();
90  }
91
92  uint8* writable_data() const {
93    DCHECK(!end_of_stream());
94    return data_.get();
95  }
96
97  int data_size() const {
98    DCHECK(!end_of_stream());
99    return size_;
100  }
101
102  const uint8* side_data() const {
103    DCHECK(!end_of_stream());
104    return side_data_.get();
105  }
106
107  int side_data_size() const {
108    DCHECK(!end_of_stream());
109    return side_data_size_;
110  }
111
112  // A discard window indicates the amount of data which should be discard from
113  // this buffer after decoding.  The first value is the amount of the front and
114  // the second the amount off the back.  A value of kInfiniteDuration() for the
115  // first value indicates the entire buffer should be discarded; the second
116  // value must be base::TimeDelta() in this case.
117  typedef std::pair<base::TimeDelta, base::TimeDelta> DiscardPadding;
118  const DiscardPadding& discard_padding() const {
119    DCHECK(!end_of_stream());
120    return discard_padding_;
121  }
122
123  void set_discard_padding(const DiscardPadding& discard_padding) {
124    DCHECK(!end_of_stream());
125    discard_padding_ = discard_padding;
126  }
127
128  const DecryptConfig* decrypt_config() const {
129    DCHECK(!end_of_stream());
130    return decrypt_config_.get();
131  }
132
133  void set_decrypt_config(scoped_ptr<DecryptConfig> decrypt_config) {
134    DCHECK(!end_of_stream());
135    decrypt_config_ = decrypt_config.Pass();
136  }
137
138  // If there's no data in this buffer, it represents end of stream.
139  bool end_of_stream() const {
140    return data_ == NULL;
141  }
142
143  // Indicates this buffer is part of a splice around |splice_timestamp_|.
144  // Returns kNoTimestamp() if the buffer is not part of a splice.
145  base::TimeDelta splice_timestamp() const {
146    DCHECK(!end_of_stream());
147    return splice_timestamp_;
148  }
149
150  // When set to anything but kNoTimestamp() indicates this buffer is part of a
151  // splice around |splice_timestamp|.
152  void set_splice_timestamp(base::TimeDelta splice_timestamp) {
153    DCHECK(!end_of_stream());
154    splice_timestamp_ = splice_timestamp;
155  }
156
157  // Returns a human-readable string describing |*this|.
158  std::string AsHumanReadableString();
159
160 protected:
161  friend class base::RefCountedThreadSafe<DecoderBuffer>;
162
163  // Allocates a buffer of size |size| >= 0 and copies |data| into it.  Buffer
164  // will be padded and aligned as necessary.  If |data| is NULL then |data_| is
165  // set to NULL and |buffer_size_| to 0.
166  DecoderBuffer(const uint8* data, int size,
167                const uint8* side_data, int side_data_size);
168  virtual ~DecoderBuffer();
169
170 private:
171  base::TimeDelta timestamp_;
172  base::TimeDelta duration_;
173
174  int size_;
175  scoped_ptr<uint8, base::AlignedFreeDeleter> data_;
176  int side_data_size_;
177  scoped_ptr<uint8, base::AlignedFreeDeleter> side_data_;
178  scoped_ptr<DecryptConfig> decrypt_config_;
179  DiscardPadding discard_padding_;
180  base::TimeDelta splice_timestamp_;
181
182  // Constructor helper method for memory allocations.
183  void Initialize();
184
185  DISALLOW_COPY_AND_ASSIGN(DecoderBuffer);
186};
187
188}  // namespace media
189
190#endif  // MEDIA_BASE_DECODER_BUFFER_H_
191