audio_sink.hpp

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// This file is part of playd.
// playd is licensed under the MIT licence: see LICENSE.txt.

#ifndef PLAYD_AUDIO_SINK_HPP
#define PLAYD_AUDIO_SINK_HPP

#include <array>
#include <cstdint>
#include <memory>
#include <string>
#include <utility>
#include <vector>

#include "SDL.h"

#include "audio.hpp"
#include "audio_source.hpp"
#include "ringbuffer.hpp"
#include "sample_formats.hpp"

class AudioSink
{
public:
    using TransferIterator = AudioSource::DecodeVector::iterator;

    virtual ~AudioSink() = default;

    virtual void Start() = 0;

    virtual void Stop() = 0;

    virtual Audio::State State();

    virtual std::uint64_t Position() = 0;

    virtual void SetPosition(std::uint64_t samples) = 0;

    virtual void SourceOut() = 0;

    virtual void Transfer(TransferIterator &start,
                          const TransferIterator &end) = 0;
};

class SdlAudioSink : public AudioSink
{
public:
    SdlAudioSink(const AudioSource &source, int device_id);

    ~SdlAudioSink() override;

    void Start() override;
    void Stop() override;
    Audio::State State() override;
    std::uint64_t Position() override;
    void SetPosition(std::uint64_t samples) override;
    void SourceOut() override;
    void Transfer(TransferIterator &start,
                  const TransferIterator &end) override;

    void Callback(std::uint8_t *out, int nbytes);

    static std::vector<std::pair<int, std::string>> GetDevicesInfo();

    static bool IsOutputDevice(int id);

    static void InitLibrary();

    static void CleanupLibrary();

private:
    SDL_AudioDeviceID device;

    static const size_t RINGBUF_POWER;

    static const std::array<SDL_AudioFormat, SAMPLE_FORMAT_COUNT> FORMATS;

    size_t bytes_per_sample;

    RingBuffer ring_buf;

    std::uint64_t position_sample_count;

    bool source_out;

    Audio::State state;
};

#endif // PLAYD_AUDIO_SINK_HPP