Makes the WebRTC fake device capable of playing audio from a file.

media/audio/fake_audio_input_stream.h

 // Copyright (c) 2012 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.
 //
 // A fake implementation of AudioInputStream, useful for testing purpose.
 
 #ifndef MEDIA_AUDIO_FAKE_AUDIO_INPUT_STREAM_H_
 #define MEDIA_AUDIO_FAKE_AUDIO_INPUT_STREAM_H_
 
 #include <vector>
 
+#include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
+#include "media/audio/sounds/wav_audio_handler.h"
 
 namespace media {
 
 class AudioBus;
 class AudioManagerBase;
 
+// This class can either generate a beep sound or play audio from a file.
 class MEDIA_EXPORT FakeAudioInputStream
     : public AudioInputStream {
  public:
-  static AudioInputStream* MakeFakeStream(AudioManagerBase* manager,
-                                          const AudioParameters& params);
+  static AudioInputStream* MakeFakeStream(
+      AudioManagerBase* manager, const AudioParameters& params);
 
   bool Open() override;
   void Start(AudioInputCallback* callback) override;
   void Stop() override;
   void Close() override;
   double GetMaxVolume() override;
   void SetVolume(double volume) override;
   double GetVolume() override;
   bool IsMuted() override;
   void SetAutomaticGainControl(bool enabled) override;
   bool GetAutomaticGainControl() override;
 
   // Generate one beep sound. This method is called by
   // FakeVideoCaptureDevice to test audio/video synchronization.
   // This is a static method because FakeVideoCaptureDevice is
   // disconnected from an audio device. This means only one instance of
   // this class gets to respond, which is okay because we assume there's
   // only one stream for this testing purpose.
   // TODO(hclam): Make this non-static. To do this we'll need to fix
   // crbug.com/159053 such that video capture device is aware of audio
   // input stream.
   static void BeepOnce();
 
  private:
   FakeAudioInputStream(AudioManagerBase* manager,
                        const AudioParameters& params);
-
   ~FakeAudioInputStream() override;
 
   void DoCallback();
 
+  // Opens this stream reading from a |wav_filename| rather than beeping.
+  void OpenInFileMode(const base::FilePath& wav_filename);
+
+  // Returns true if the device is playing from a file; false if we're beeping.
+  bool PlayingFromFile();
+
+  void PlayFileLooping();
+  void PlayBeep();
+
   AudioManagerBase* audio_manager_;
   AudioInputCallback* callback_;
-  scoped_ptr<uint8[]> buffer_;
+  scoped_ptr<char[]> buffer_;

[DaleCurtis, 2014/11/18 21:59:17]

Why? If anything I'd think this should be moving to uint8_t.

[phoglund_chromium, 2014/11/19 09:56:09]

I didn't reckon it mattered, and it saves me a cast or two when I create a
StringPiece for the wav_file_data_ (so to be clear: the casts are for
wav_file_data_, and I changed this one to be consistent).

I can certainly change back to uint8_t if you feel strongly about it.

[DaleCurtis, 2014/11/20 19:13:47]

It should be uint8_t. 

[phoglund_chromium, 2014/11/20 19:48:31]

Done.

   int buffer_size_;
   AudioParameters params_;
   const scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   base::TimeTicks last_callback_time_;
   base::TimeDelta callback_interval_;
   base::TimeDelta interval_from_last_beep_;
   int beep_duration_in_buffers_;
   int beep_generated_in_buffers_;
   int beep_period_in_frames_;
-  int frames_elapsed_;
   scoped_ptr<media::AudioBus> audio_bus_;
+  scoped_ptr<char[]> wav_file_data_;

[DaleCurtis, 2014/11/18 21:59:17]

Ditto.

[phoglund_chromium, 2014/11/19 09:56:09]

See above.

+  scoped_ptr<media::WavAudioHandler> wav_audio_handler_;
+  int wav_file_read_pos_;
 
   // Allows us to run tasks on the FakeAudioInputStream instance which are
   // bound by its lifetime.
   base::WeakPtrFactory<FakeAudioInputStream> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeAudioInputStream);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_FAKE_AUDIO_INPUT_STREAM_H_