Duckstation/src/common/audio_stream.h
Connor McLaughlin c89d94c2ff Move Cubeb AudioStream to FrontendCommon
This way it doesn't need to be built for libretro.
2020-10-11 12:21:08 +10:00

91 lines
2.4 KiB
C++

#pragma once
#include "fifo_queue.h"
#include "types.h"
#include <condition_variable>
#include <memory>
#include <mutex>
#include <vector>
// Uses signed 16-bits samples.
class AudioStream
{
public:
using SampleType = s16;
enum : u32
{
DefaultOutputSampleRate = 44100,
DefaultBufferSize = 2048,
MaxSamples = 32768,
FullVolume = 100
};
AudioStream();
virtual ~AudioStream();
u32 GetOutputSampleRate() const { return m_output_sample_rate; }
u32 GetChannels() const { return m_channels; }
u32 GetBufferSize() const { return m_buffer_size; }
s32 GetOutputVolume() const { return m_output_volume; }
bool IsSyncing() const { return m_sync; }
bool Reconfigure(u32 output_sample_rate = DefaultOutputSampleRate, u32 channels = 1,
u32 buffer_size = DefaultBufferSize);
void SetSync(bool enable) { m_sync = enable; }
virtual void SetOutputVolume(u32 volume);
void PauseOutput(bool paused);
void EmptyBuffers();
void Shutdown();
void BeginWrite(SampleType** buffer_ptr, u32* num_frames);
void WriteFrames(const SampleType* frames, u32 num_frames);
void EndWrite(u32 num_frames);
static std::unique_ptr<AudioStream> CreateNullAudioStream();
// Latency computation - returns values in seconds
static float GetMaxLatency(u32 sample_rate, u32 buffer_size);
protected:
virtual bool OpenDevice() = 0;
virtual void PauseDevice(bool paused) = 0;
virtual void CloseDevice() = 0;
virtual void FramesAvailable() = 0;
ALWAYS_INLINE static SampleType ApplyVolume(SampleType sample, u32 volume)
{
return s16((s32(sample) * s32(volume)) / 100);
}
bool SetBufferSize(u32 buffer_size);
bool IsDeviceOpen() const { return (m_output_sample_rate > 0); }
u32 GetSamplesAvailable() const;
u32 GetSamplesAvailableLocked() const;
void ReadFrames(SampleType* samples, u32 num_frames, bool apply_volume);
void DropFrames(u32 count);
u32 m_output_sample_rate = 0;
u32 m_channels = 0;
u32 m_buffer_size = 0;
// volume, 0-100
u32 m_output_volume = FullVolume;
private:
ALWAYS_INLINE u32 GetBufferSpace() const { return (m_max_samples - m_buffer.GetSize()); }
void EnsureBuffer(u32 size);
HeapFIFOQueue<SampleType, MaxSamples> m_buffer;
mutable std::mutex m_buffer_mutex;
std::condition_variable m_buffer_draining_cv;
std::vector<SampleType> m_resample_buffer;
u32 m_max_samples = 0;
bool m_output_paused = true;
bool m_sync = true;
};