[chromecast] Slew stream volume changes in StreamMixerAlsa.

chromecast/media/cma/backend/alsa/stream_mixer_alsa_input_impl.h

 // Copyright 2015 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 CHROMECAST_MEDIA_CMA_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_IMPL_H_
 #define CHROMECAST_MEDIA_CMA_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_IMPL_H_
 
 #include <deque>
 #include <memory>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "chromecast/media/cma/backend/alsa/media_pipeline_backend_alsa.h"
+#include "chromecast/media/cma/backend/alsa/slew_volume.h"
 #include "chromecast/media/cma/backend/alsa/stream_mixer_alsa.h"
 #include "chromecast/media/cma/backend/alsa/stream_mixer_alsa_input.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace media {
 class AudioBus;
 class MultiChannelResampler;
@@ skipping 79 matching lines @@
 
   // Prevents any further calls to the delegate (ie, called when the delegate
   // is being destroyed).
   void PreventDelegateCalls();
 
   State state() const { return state_; }
 
  private:
   // StreamMixerAlsa::InputQueue implementation:
   int input_samples_per_second() const override;
-  float volume_multiplier() const override;
   bool primary() const override;
   bool IsDeleting() const override;
   void Initialize(const MediaPipelineBackendAlsa::RenderingDelay&
                       mixer_rendering_delay) override;
   int MaxReadSize() override;
   void GetResampledData(::media::AudioBus* dest, int frames) override;
+  void VolumeScaleAccumulate(const float* src,
+                             int frames,
+                             float* dest) override;
   void AfterWriteFrames(const MediaPipelineBackendAlsa::RenderingDelay&
                             mixer_rendering_delay) override;
   void SignalError(StreamMixerAlsaInput::MixerError error) override;
   void PrepareToDelete(const OnReadyToDeleteCb& delete_cb) override;
 
   // Tells the mixer to delete |this|. Makes sure not to call |delete_cb_| more
   // than once for |this|.
   void DeleteThis();
   MediaPipelineBackendAlsa::RenderingDelay QueueData(
       const scoped_refptr<DecoderBufferBase>& data);
   void PostPcmCallback(const MediaPipelineBackendAlsa::RenderingDelay& delay);
   void DidQueueData(bool end_of_stream);
   void ReadCB(int frame_delay, ::media::AudioBus* output);
   void FillFrames(int frame_delay, ::media::AudioBus* output, int frames);
   int NormalFadeFrames();
   void FadeIn(::media::AudioBus* dest, int frames);
   void FadeOut(::media::AudioBus* dest, int frames);
   void PostError(StreamMixerAlsaInput::MixerError error);
 
   StreamMixerAlsaInput::Delegate* const delegate_;
   const int input_samples_per_second_;
   const bool primary_;
   StreamMixerAlsa* const mixer_;
   const scoped_refptr<base::SingleThreadTaskRunner> mixer_task_runner_;
   const scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner_;
 
   double resample_ratio_;
 
   State state_;
-  float volume_multiplier_;
+  SlewVolume slew_volume_;
 
   base::Lock queue_lock_;  // Lock for the following queue-related members.
   scoped_refptr<DecoderBufferBase> pending_data_;
   std::deque<scoped_refptr<DecoderBufferBase>> queue_;
   int queued_frames_;
   double queued_frames_including_resampler_;
   MediaPipelineBackendAlsa::RenderingDelay mixer_rendering_delay_;
   // End of members that queue_lock_ controls access for.
 
   int current_buffer_offset_;
   int max_queued_frames_;
   int fade_frames_remaining_;
   int fade_out_frames_total_;
   int zeroed_frames_;  // current count of consecutive 0-filled frames
 
   OnReadyToDeleteCb delete_cb_;
 
   std::unique_ptr<::media::MultiChannelResampler> resampler_;
 
   base::WeakPtr<StreamMixerAlsaInputImpl> weak_this_;
   base::WeakPtrFactory<StreamMixerAlsaInputImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(StreamMixerAlsaInputImpl);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BACKEND_ALSA_STREAM_MIXER_ALSA_INPUT_IMPL_H_