Decode entire in-memory file for WebAudio

media/filters/audio_file_reader.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_FILTERS_AUDIO_FILE_READER_H_
 #define MEDIA_FILTERS_AUDIO_FILE_READER_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 20 matching lines @@
   // simply maintains a weak reference to it.
   explicit AudioFileReader(FFmpegURLProtocol* protocol);
   virtual ~AudioFileReader();
 
   // Open() reads the audio data format so that the sample_rate(),
   // channels(), GetDuration(), and GetNumberOfFrames() methods can be called.
   // It returns |true| on success.
   bool Open();
   void Close();
 
+  // Returns true if (an estimated) duration of the audio data is
+  // known.  Must be called after Open();
+  bool HasKnownDuration() const;
+
   // After a call to Open(), attempts to fully fill |audio_bus| with decoded
   // audio data.  Any unfilled frames will be zeroed out.
   // |audio_data| must be of the same size as channels().
   // The audio data will be decoded as floating-point linear PCM with
   // a nominal range of -1.0 -> +1.0.
   // Returns the number of sample-frames actually read which will always be
   // <= audio_bus->frames()
   int Read(AudioBus* audio_bus);
 
+  std::unique_ptr<AudioBus> StreamingRead();
+
   // These methods can be called once Open() has been called.
   int channels() const { return channels_; }
   int sample_rate() const { return sample_rate_; }
 
   // Please note that GetDuration() and GetNumberOfFrames() attempt to be
   // accurate, but are only estimates.  For some encoded formats, the actual
   // duration of the file can only be determined once all the file data has been
   // read. The Read() method returns the actual number of sample-frames it has
   // read.
   base::TimeDelta GetDuration() const;
@@ skipping 36 matching lines @@
 
   // AVSampleFormat initially requested; not Chrome's SampleFormat.
   int av_sample_format_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioFileReader);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_AUDIO_FILE_READER_H_