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      1 // Copyright 2014 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 CHROMECAST_MEDIA_CMA_BASE_BUFFERING_FRAME_PROVIDER_H_
      6 #define CHROMECAST_MEDIA_CMA_BASE_BUFFERING_FRAME_PROVIDER_H_
      7 
      8 #include <list>
      9 
     10 #include "base/memory/ref_counted.h"
     11 #include "base/memory/scoped_ptr.h"
     12 #include "base/memory/weak_ptr.h"
     13 #include "base/threading/thread_checker.h"
     14 #include "chromecast/media/cma/base/coded_frame_provider.h"
     15 #include "media/base/audio_decoder_config.h"
     16 #include "media/base/video_decoder_config.h"
     17 
     18 namespace chromecast {
     19 namespace media {
     20 class DecoderBufferBase;
     21 
     22 // BufferingFrameProvider -
     23 // Fetch some data from another CodedFrameProvider up to a certain size limit.
     24 class BufferingFrameProvider : public CodedFrameProvider {
     25  public:
     26   typedef base::Callback<void(const scoped_refptr<DecoderBufferBase>&, bool)>
     27       FrameBufferedCB;
     28 
     29   // Creates a frame provider that buffers coded frames up to the
     30   // |max_buffer_size| limit (given as a number of bytes).
     31   // |max_frame_size| corresponds to an upper bound of the expected frame size.
     32   // Each time a frame is buffered, |frame_buffered_cb| is invoked with the
     33   // last frame buffered. The second parameter of the callback indicates
     34   // whether the maximum capacity has been reached, i.e. whether the next frame
     35   // size might overflow the buffer: |total_buffer_size_| + next_frame_size
     36   // might be greater than |max_buffer_size|.
     37   // Note: takes ownership of |coded_frame_provider|.
     38   BufferingFrameProvider(
     39       scoped_ptr<CodedFrameProvider> coded_frame_provider,
     40       size_t max_buffer_size,
     41       size_t max_frame_size,
     42       const FrameBufferedCB& frame_buffered_cb);
     43   virtual ~BufferingFrameProvider();
     44 
     45   // CodedFrameProvider implementation.
     46   virtual void Read(const ReadCB& read_cb) OVERRIDE;
     47   virtual void Flush(const base::Closure& flush_cb) OVERRIDE;
     48 
     49  private:
     50   class BufferWithConfig {
     51    public:
     52     BufferWithConfig(
     53         const scoped_refptr<DecoderBufferBase>& buffer,
     54         const ::media::AudioDecoderConfig& audio_config,
     55         const ::media::VideoDecoderConfig& video_config);
     56     ~BufferWithConfig();
     57 
     58     const scoped_refptr<DecoderBufferBase>& buffer() const { return buffer_; }
     59     const ::media::AudioDecoderConfig& audio_config() const {
     60       return audio_config_;
     61     }
     62     const ::media::VideoDecoderConfig& video_config() const {
     63       return video_config_;
     64     }
     65 
     66    private:
     67     scoped_refptr<DecoderBufferBase> buffer_;
     68     ::media::AudioDecoderConfig audio_config_;
     69     ::media::VideoDecoderConfig video_config_;
     70   };
     71 
     72   void OnNewBuffer(const scoped_refptr<DecoderBufferBase>& buffer,
     73                    const ::media::AudioDecoderConfig& audio_config,
     74                    const ::media::VideoDecoderConfig& video_config);
     75   void RequestBufferIfNeeded();
     76   void CompleteReadIfNeeded();
     77 
     78   base::ThreadChecker thread_checker_;
     79 
     80   // Frame provider the buffering frame provider fetches data from.
     81   scoped_ptr<CodedFrameProvider> coded_frame_provider_;
     82 
     83   // Indicates whether there is a pending read request on
     84   // |coded_frame_provider_|.
     85   bool is_pending_request_;
     86 
     87   // Indicates whether the end of stream has been reached.
     88   bool is_eos_;
     89 
     90   std::list<BufferWithConfig> buffer_list_;
     91 
     92   // Size in bytes of audio/video buffers in |buffer_list_|.
     93   size_t total_buffer_size_;
     94 
     95   // Max amount of data to buffer.
     96   // i.e. this is the maximum size of buffers in |buffer_list_|.
     97   const size_t max_buffer_size_;
     98 
     99   // Maximum expected frame size.
    100   const size_t max_frame_size_;
    101 
    102   // Callback invoked each time there is a new frame buffered.
    103   FrameBufferedCB frame_buffered_cb_;
    104 
    105   // Pending read callback.
    106   ReadCB read_cb_;
    107 
    108   base::WeakPtrFactory<BufferingFrameProvider> weak_factory_;
    109   base::WeakPtr<BufferingFrameProvider> weak_this_;
    110 
    111   DISALLOW_COPY_AND_ASSIGN(BufferingFrameProvider);
    112 };
    113 
    114 }  // namespace media
    115 }  // namespace chromecast
    116 
    117 #endif  // CHROMECAST_MEDIA_CMA_BASE_BUFFERING_FRAME_PROVIDER_H_
    118