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      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_DATA_BUFFER_H_
      6 #define MEDIA_BASE_DATA_BUFFER_H_
      7 
      8 #include "base/logging.h"
      9 #include "base/memory/ref_counted.h"
     10 #include "base/memory/scoped_ptr.h"
     11 #include "base/time/time.h"
     12 #include "media/base/media_export.h"
     13 
     14 namespace media {
     15 
     16 // A simple buffer that takes ownership of the given data pointer or allocates
     17 // as necessary.
     18 //
     19 // Unlike DecoderBuffer, allocations are assumed to be allocated with the
     20 // default memory allocator (i.e., new uint8[]).
     21 //
     22 // NOTE: It is illegal to call any method when end_of_stream() is true.
     23 class MEDIA_EXPORT DataBuffer : public base::RefCountedThreadSafe<DataBuffer> {
     24  public:
     25   // Allocates buffer of size |buffer_size| >= 0.
     26   explicit DataBuffer(int buffer_size);
     27 
     28   // Assumes valid data of size |buffer_size|.
     29   DataBuffer(scoped_ptr<uint8[]> buffer, int buffer_size);
     30 
     31   // Create a DataBuffer whose |data_| is copied from |data|.
     32   //
     33   // |data| must not be null and |size| must be >= 0.
     34   static scoped_refptr<DataBuffer> CopyFrom(const uint8* data, int size);
     35 
     36   // Create a DataBuffer indicating we've reached end of stream.
     37   //
     38   // Calling any method other than end_of_stream() on the resulting buffer
     39   // is disallowed.
     40   static scoped_refptr<DataBuffer> CreateEOSBuffer();
     41 
     42   base::TimeDelta timestamp() const {
     43     DCHECK(!end_of_stream());
     44     return timestamp_;
     45   }
     46 
     47   void set_timestamp(const base::TimeDelta& timestamp) {
     48     DCHECK(!end_of_stream());
     49     timestamp_ = timestamp;
     50   }
     51 
     52   base::TimeDelta duration() const {
     53     DCHECK(!end_of_stream());
     54     return duration_;
     55   }
     56 
     57   void set_duration(const base::TimeDelta& duration) {
     58     DCHECK(!end_of_stream());
     59     duration_ = duration;
     60   }
     61 
     62   const uint8* data() const {
     63     DCHECK(!end_of_stream());
     64     return data_.get();
     65   }
     66 
     67   uint8* writable_data() {
     68     DCHECK(!end_of_stream());
     69     return data_.get();
     70   }
     71 
     72   // The size of valid data in bytes.
     73   //
     74   // Setting this value beyond the buffer size is disallowed.
     75   int data_size() const {
     76     DCHECK(!end_of_stream());
     77     return data_size_;
     78   }
     79 
     80   void set_data_size(int data_size) {
     81     DCHECK(!end_of_stream());
     82     CHECK_LE(data_size, buffer_size_);
     83     data_size_ = data_size;
     84   }
     85 
     86   // If there's no data in this buffer, it represents end of stream.
     87   bool end_of_stream() const { return data_ == NULL; }
     88 
     89  protected:
     90   friend class base::RefCountedThreadSafe<DataBuffer>;
     91 
     92   // Allocates buffer of size |data_size|, copies [data,data+data_size) to
     93   // the allocated buffer and sets data size to |data_size|.
     94   //
     95   // If |data| is null an end of stream buffer is created.
     96   DataBuffer(const uint8* data, int data_size);
     97 
     98   virtual ~DataBuffer();
     99 
    100  private:
    101   base::TimeDelta timestamp_;
    102   base::TimeDelta duration_;
    103 
    104   scoped_ptr<uint8[]> data_;
    105   int buffer_size_;
    106   int data_size_;
    107 
    108   DISALLOW_COPY_AND_ASSIGN(DataBuffer);
    109 };
    110 
    111 }  // namespace media
    112 
    113 #endif  // MEDIA_BASE_DATA_BUFFER_H_
    114