kaliber/src/engine/audio/mixer_input.h

111 lines
3.2 KiB
C++

#ifndef ENGINE_AUDIO_MIXER_INPUT_H
#define ENGINE_AUDIO_MIXER_INPUT_H
#include <atomic>
#include <memory>
#include "base/closure.h"
namespace eng {
class AudioBus;
class AudioMixer;
// An audio input stream that gets mixed and rendered to the audio sink. Handles
// playback and volume control.
class MixerInput : public std::enable_shared_from_this<MixerInput> {
public:
enum Flags { kLoop = 1, kStopped = 2, kSimulateStereo = 4 };
~MixerInput();
static std::shared_ptr<MixerInput> Create();
bool IsValid() const { return !!audio_bus_; }
// Set AudioBus for playback. If this MixerInput is already playing, keeps it
// as pending and sets once playback ends.
void SetAudioBus(std::shared_ptr<AudioBus> audio_bus);
// Starts playback. Remembers last stream position. Resets the stream position
// if restart is true.
void Play(AudioMixer* mixer, bool restart);
// Stops playback. Does not reset stream position.
void Stop();
// Set whether the playback should loop or not.
void SetLoop(bool loop);
// Simulate stereo effect slightly delays one channel.
void SetSimulateStereo(bool simulate);
// Vary basic resampling for sound variations.
void SetResampleStep(size_t value);
// Set the current volume, max volume and volume increment steps.
void SetAmplitude(float value);
void SetMaxAmplitude(float value);
void SetAmplitudeInc(float value);
// Set a callback to be called once playback ends.
void SetEndCallback(base::Closure cb);
// Getters
std::shared_ptr<AudioBus> GetAudioBus() const { return audio_bus_; }
unsigned GetFlags() const { return flags_.load(std::memory_order_relaxed); }
size_t GetStep() const { return step_.load(std::memory_order_relaxed); }
float GetAmplitude() const {
return amplitude_.load(std::memory_order_relaxed);
}
float GetAmplitudeInc() const {
return amplitude_inc_.load(std::memory_order_relaxed);
}
float GetMaxAmplitude() const {
return max_amplitude_.load(std::memory_order_relaxed);
}
size_t GetSrcIndex() const { return src_index_; }
size_t GetAccumulator() const { return accumulator_; }
bool IsStreamingInProgress() const;
// Called by the mixer to save the last sample position.
void SetPosition(size_t index, int accumulator);
// Called by the mixer when more data is needed.
bool OnMoreData(bool loop);
// Called by the mixer when playback ends.
void OnRemovedFromMixer();
private:
// Active AudioBus.
std::shared_ptr<AudioBus> audio_bus_;
// AudioBus to be set as active once playback ends.
std::shared_ptr<AudioBus> pending_audio_bus_;
// Stream position.
size_t src_index_ = 0;
size_t accumulator_ = 0;
// Accessed by main thread only.
bool playing_ = false;
base::Closure end_cb_;
base::Closure restart_cb_;
// Accessed by main thread and audio thread.
std::atomic<unsigned> flags_{0};
std::atomic<size_t> step_{100};
std::atomic<float> amplitude_{1.0f};
std::atomic<float> amplitude_inc_{0};
std::atomic<float> max_amplitude_{1.0f};
// Accessed by audio thread and decoding worker thread.
std::atomic<bool> streaming_in_progress_{false};
MixerInput();
};
} // namespace eng
#endif // ENGINE_AUDIO_MIXER_INPUT_H