godot/scene/resources/audio_stream_sample.h

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/*  audio_stream_sample.h                                                */
/*************************************************************************/
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/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
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#ifndef AUDIOSTREAMSAMPLE_H
#define AUDIOSTREAMSAMPLE_H

#include "servers/audio/audio_stream.h"

class AudioStreamSample;

class AudioStreamPlaybackSample : public AudioStreamPlayback {

	GDCLASS(AudioStreamPlaybackSample, AudioStreamPlayback)
	enum {
		MIX_FRAC_BITS = 13,
		MIX_FRAC_LEN = (1 << MIX_FRAC_BITS),
		MIX_FRAC_MASK = MIX_FRAC_LEN - 1,
	};

	struct IMA_ADPCM_State {

		int16_t step_index;
		int32_t predictor;
		/* values at loop point */
		int16_t loop_step_index;
		int32_t loop_predictor;
		int32_t last_nibble;
		int32_t loop_pos;
		int32_t window_ofs;
	} ima_adpcm[2];

	int64_t offset;
	int sign;
	bool active;
	friend class AudioStreamSample;
	Ref<AudioStreamSample> base;

	template <class Depth, bool is_stereo, bool is_ima_adpcm>
	void do_resample(const Depth *p_src, AudioFrame *p_dst, int64_t &offset, int32_t &increment, uint32_t amount, IMA_ADPCM_State *ima_adpcm);

public:
	virtual void start(float p_from_pos = 0.0);
	virtual void stop();
	virtual bool is_playing() const;

	virtual int get_loop_count() const; //times it looped

	virtual float get_playback_position() const;
	virtual void seek(float p_time);

	virtual void mix(AudioFrame *p_buffer, float p_rate_scale, int p_frames);

	virtual float get_length() const; //if supported, otherwise return 0

	AudioStreamPlaybackSample();
};

class AudioStreamSample : public AudioStream {
	GDCLASS(AudioStreamSample, AudioStream)
	RES_BASE_EXTENSION("sample")

public:
	enum Format {
		FORMAT_8_BITS,
		FORMAT_16_BITS,
		FORMAT_IMA_ADPCM
	};

	enum LoopMode {
		LOOP_DISABLED,
		LOOP_FORWARD,
		LOOP_PING_PONG
	};

private:
	friend class AudioStreamPlaybackSample;

	enum {
		DATA_PAD = 16 //padding for interpolation
	};

	Format format;
	LoopMode loop_mode;
	bool stereo;
	int loop_begin;
	int loop_end;
	int mix_rate;
	void *data;
	uint32_t data_bytes;

protected:
	static void _bind_methods();

public:
	void set_format(Format p_format);
	Format get_format() const;

	void set_loop_mode(LoopMode p_loop_mode);
	LoopMode get_loop_mode() const;

	void set_loop_begin(int p_frame);
	int get_loop_begin() const;

	void set_loop_end(int p_frame);
	int get_loop_end() const;

	void set_mix_rate(int p_hz);
	int get_mix_rate() const;

	void set_stereo(bool p_enable);
	bool is_stereo() const;

	void set_data(const PoolVector<uint8_t> &p_data);
	PoolVector<uint8_t> get_data() const;

	virtual Ref<AudioStreamPlayback> instance_playback();
	virtual String get_stream_name() const;

	AudioStreamSample();
	~AudioStreamSample();
};

VARIANT_ENUM_CAST(AudioStreamSample::Format)
VARIANT_ENUM_CAST(AudioStreamSample::LoopMode)

#endif // AUDIOSTREAMSample_H