media/audio/simple_sources.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_AUDIO_SIMPLE_SOURCES_H_
   6 #define MEDIA_AUDIO_SIMPLE_SOURCES_H_
   7
   8 #include "base/files/file_path.h"
   9 #include "base/synchronization/lock.h"
  10 #include "media/audio/audio_io.h"
  11 #include "media/base/audio_converter.h"
  12 #include "media/base/seekable_buffer.h"
  13
  14 namespace media {
  15
  16 class WavAudioHandler;
  17
  18 // An audio source that produces a pure sinusoidal tone.
  19 class MEDIA_EXPORT SineWaveAudioSource
  20     : public AudioOutputStream::AudioSourceCallback {
  21  public:
  22   // |channels| is the number of audio channels, |freq| is the frequency in
  23   // hertz and it has to be less than half of the sampling frequency
  24   // |sample_freq| or else you will get aliasing.
  25   SineWaveAudioSource(int channels, double freq, double sample_freq);
  26   ~SineWaveAudioSource() override;
  27
  28   // Return up to |cap| samples of data via OnMoreData().  Use Reset() to
  29   // allow more data to be served.
  30   void CapSamples(int cap);
  31   void Reset();
  32
  33   // Implementation of AudioSourceCallback.
  34   int OnMoreData(AudioBus* audio_bus, uint32 total_bytes_delay) override;
  35   void OnError(AudioOutputStream* stream) override;
  36
  37   // The number of OnMoreData() and OnError() calls respectively.
  38   int callbacks() { return callbacks_; }
  39   int errors() { return errors_; }
  40
  41  protected:
  42   int channels_;
  43   double f_;
  44   int time_state_;
  45   int cap_;
  46   int callbacks_;
  47   int errors_;
  48   base::Lock time_lock_;
  49 };
  50
  51 class FileSource : public AudioOutputStream::AudioSourceCallback,
  52                    public AudioConverter::InputCallback {
  53  public:
  54   FileSource(const AudioParameters& params,
  55              const base::FilePath& path_to_wav_file);
  56   ~FileSource() override;
  57
  58   // Implementation of AudioSourceCallback.
  59   int OnMoreData(AudioBus* audio_bus, uint32 total_bytes_delay) override;
  60   void OnError(AudioOutputStream* stream) override;
  61
  62  private:
  63   AudioParameters params_;
  64   base::FilePath path_to_wav_file_;
  65   scoped_ptr<uint8[]> wav_file_data_;
  66   scoped_ptr<WavAudioHandler> wav_audio_handler_;
  67   scoped_ptr<AudioConverter> file_audio_converter_;
  68   int wav_file_read_pos_;
  69   bool load_failed_;
  70
  71   // Provides audio data from wav_audio_handler_ into the file audio converter.
  72   double ProvideInput(AudioBus* audio_bus,
  73                       base::TimeDelta buffer_delay) override;
  74
  75   // Loads the wav file on the first OnMoreData invocation.
  76   void LoadWavFile(const base::FilePath& path_to_wav_file);
  77 };
  78
  79 class BeepingSource : public AudioOutputStream::AudioSourceCallback {
  80  public:
  81   BeepingSource(const AudioParameters& params);
  82   ~BeepingSource() override;
  83
  84   // Implementation of AudioSourceCallback.
  85   int OnMoreData(AudioBus* audio_bus, uint32 total_bytes_delay) override;
  86   void OnError(AudioOutputStream* stream) override;
  87
  88   static void BeepOnce();
  89  private:
  90   int buffer_size_;
  91   scoped_ptr<uint8[]> buffer_;
  92   AudioParameters params_;
  93   base::TimeTicks last_callback_time_;
  94   base::TimeDelta interval_from_last_beep_;
  95   int beep_duration_in_buffers_;
  96   int beep_generated_in_buffers_;
  97   int beep_period_in_frames_;
  98 };
  99
 100 }  // namespace media
 101
 102 #endif  // MEDIA_AUDIO_SIMPLE_SOURCES_H_