media/base/fake_audio_render_callback.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_BASE_FAKE_AUDIO_RENDER_CALLBACK_H_
   6 #define MEDIA_BASE_FAKE_AUDIO_RENDER_CALLBACK_H_
   7
   8 #include "media/base/audio_converter.h"
   9 #include "media/base/audio_renderer_sink.h"
  10 #include "testing/gmock/include/gmock/gmock.h"
  11
  12 namespace media {
  13
  14 // Fake RenderCallback which will fill each request with a sine wave.  Sine
  15 // state is kept across callbacks.  State can be reset to default via reset().
  16 // Also provide an interface to AudioTransformInput.
  17 class FakeAudioRenderCallback
  18     : public AudioRendererSink::RenderCallback,
  19       public AudioConverter::InputCallback {
  20  public:
  21   // The function used to fulfill Render() is f(x) = sin(2 * PI * x * |step|),
  22   // where x = [|number_of_frames| * m, |number_of_frames| * (m + 1)] and m =
  23   // the number of Render() calls fulfilled thus far.
  24   explicit FakeAudioRenderCallback(double step);
  25   virtual ~FakeAudioRenderCallback();
  26
  27   // Renders a sine wave into the provided audio data buffer.  If |half_fill_|
  28   // is set, will only fill half the buffer.
  29   virtual int Render(AudioBus* audio_bus,
  30                      int audio_delay_milliseconds) OVERRIDE;
  31   MOCK_METHOD0(OnRenderError, void());
  32
  33   // AudioTransform::ProvideAudioTransformInput implementation.
  34   virtual double ProvideInput(AudioBus* audio_bus,
  35                               base::TimeDelta buffer_delay) OVERRIDE;
  36
  37   // Toggles only filling half the requested amount during Render().
  38   void set_half_fill(bool half_fill) { half_fill_ = half_fill; }
  39
  40   // Reset the sine state to initial value.
  41   void reset() { x_ = 0; }
  42
  43   // Returns the last |audio_delay_milliseconds| provided to Render() or -1 if
  44   // no Render() call occurred.
  45   int last_audio_delay_milliseconds() { return last_audio_delay_milliseconds_; }
  46
  47   // Set volume information used by ProvideAudioTransformInput().
  48   void set_volume(double volume) { volume_ = volume; }
  49
  50  private:
  51   bool half_fill_;
  52   double x_;
  53   double step_;
  54   int last_audio_delay_milliseconds_;
  55   double volume_;
  56
  57   DISALLOW_COPY_AND_ASSIGN(FakeAudioRenderCallback);
  58 };
  59
  60 }  // namespace media
  61
  62 #endif  // MEDIA_BASE_FAKE_AUDIO_RENDER_CALLBACK_H_