media/base/decoder_buffer.h

   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
  19 namespace 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.
  30 class 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   // Indicates this buffer is part of a splice around |splice_timestamp_|.
 134   // Returns kNoTimestamp() if the buffer is not part of a splice.
 135   base::TimeDelta splice_timestamp() const {
 136     DCHECK(!end_of_stream());
 137     return splice_timestamp_;
 138   }
 139
 140   // When set to anything but kNoTimestamp() indicates this buffer is part of a
 141   // splice around |splice_timestamp|.
 142   void set_splice_timestamp(base::TimeDelta splice_timestamp) {
 143     DCHECK(!end_of_stream());
 144     splice_timestamp_ = splice_timestamp;
 145   }
 146
 147   // Returns a human-readable string describing |*this|.
 148   std::string AsHumanReadableString();
 149
 150  protected:
 151   friend class base::RefCountedThreadSafe<DecoderBuffer>;
 152
 153   // Allocates a buffer of size |size| >= 0 and copies |data| into it.  Buffer
 154   // will be padded and aligned as necessary.  If |data| is NULL then |data_| is
 155   // set to NULL and |buffer_size_| to 0.
 156   DecoderBuffer(const uint8* data, int size,
 157                 const uint8* side_data, int side_data_size);
 158   virtual ~DecoderBuffer();
 159
 160  private:
 161   base::TimeDelta timestamp_;
 162   base::TimeDelta duration_;
 163
 164   int size_;
 165   scoped_ptr<uint8, base::AlignedFreeDeleter> data_;
 166   int side_data_size_;
 167   scoped_ptr<uint8, base::AlignedFreeDeleter> side_data_;
 168   scoped_ptr<DecryptConfig> decrypt_config_;
 169   base::TimeDelta discard_padding_;
 170   base::TimeDelta splice_timestamp_;
 171
 172   // Constructor helper method for memory allocations.
 173   void Initialize();
 174
 175   DISALLOW_COPY_AND_ASSIGN(DecoderBuffer);
 176 };
 177
 178 }  // namespace media
 179
 180 #endif  // MEDIA_BASE_DECODER_BUFFER_H_