third_party/WebKit/Source/platform/audio/AudioDSPKernelProcessor.h

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#ifndef AudioDSPKernelProcessor_h
#define AudioDSPKernelProcessor_h

#include <memory>
#include "platform/audio/AudioBus.h"
#include "platform/audio/AudioProcessor.h"
#include "platform/wtf/ThreadingPrimitives.h"
#include "platform/wtf/Vector.h"

namespace blink {

class AudioBus;
class AudioDSPKernel;
class AudioProcessor;

// AudioDSPKernelProcessor processes one input -> one output (N channels each)
// It uses one AudioDSPKernel object per channel to do the processing, thus
// there is no cross-channel processing.  Despite this limitation it turns out
// to be a very common and useful type of processor.

class PLATFORM_EXPORT AudioDSPKernelProcessor : public AudioProcessor {
 public:
  // numberOfChannels may be later changed if object is not yet in an
  // "initialized" state
  AudioDSPKernelProcessor(float sample_rate, unsigned number_of_channels);

  // Subclasses create the appropriate type of processing kernel here.
  // We'll call this to create a kernel for each channel.
  virtual std::unique_ptr<AudioDSPKernel> CreateKernel() = 0;

  // AudioProcessor methods
  void Initialize() override;
  void Uninitialize() override;
  void Process(const AudioBus* source,
               AudioBus* destination,
               size_t frames_to_process) override;
  void ProcessOnlyAudioParams(size_t frames_to_process) override;
  void Reset() override;
  void SetNumberOfChannels(unsigned) override;
  unsigned NumberOfChannels() const override { return number_of_channels_; }

  double TailTime() const override;
  double LatencyTime() const override;

 protected:
  Vector<std::unique_ptr<AudioDSPKernel>> kernels_;
  mutable Mutex process_lock_;
  bool has_just_reset_;
};

}  // namespace blink

#endif  // AudioDSPKernelProcessor_h