godot/servers/audio/audio_rb_resampler.h

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#ifndef AUDIO_RB_RESAMPLER_H
#define AUDIO_RB_RESAMPLER_H
#include "typedefs.h"
#include "os/memory.h"
struct AudioRBResampler {
uint32_t rb_bits;
uint32_t rb_len;
uint32_t rb_mask;
uint32_t read_buff_len;
uint32_t channels;
uint32_t src_mix_rate;
uint32_t target_mix_rate;
volatile int rb_read_pos;
volatile int rb_write_pos;
int32_t offset; //contains the fractional remainder of the resampler
enum {
MIX_FRAC_BITS=13,
MIX_FRAC_LEN=(1<<MIX_FRAC_BITS),
MIX_FRAC_MASK=MIX_FRAC_LEN-1,
};
int16_t *read_buf;
int16_t *rb;
template<int C>
uint32_t _resample(int32_t *p_dest,int p_todo,int32_t p_increment);
public:
_FORCE_INLINE_ void flush() {
rb_read_pos=0;
rb_write_pos=0;
}
_FORCE_INLINE_ bool is_ready() const{
return rb!=NULL;
}
_FORCE_INLINE_ int get_total() const {
return rb_len-1;
}
_FORCE_INLINE_ int get_todo() const { //return amount of frames to mix
int todo;
int read_pos_cache=rb_read_pos;
if (read_pos_cache==rb_write_pos) {
todo=rb_len-1;
} else if (read_pos_cache>rb_write_pos) {
todo=read_pos_cache-rb_write_pos-1;
} else {
todo=(rb_len-rb_write_pos)+read_pos_cache-1;
}
return todo;
}
_FORCE_INLINE_ int16_t *get_write_buffer() { return read_buf; }
_FORCE_INLINE_ void write(uint32_t p_frames) {
ERR_FAIL_COND(p_frames >= rb_len);
switch(channels) {
case 1: {
for(uint32_t i=0;i<p_frames;i++) {
rb[ rb_write_pos ] = read_buf[i];
rb_write_pos=(rb_write_pos+1)&rb_mask;
}
} break;
case 2: {
for(uint32_t i=0;i<p_frames;i++) {
rb[ (rb_write_pos<<1)+0 ] = read_buf[(i<<1)+0];
rb[ (rb_write_pos<<1)+1 ] = read_buf[(i<<1)+1];
rb_write_pos=(rb_write_pos+1)&rb_mask;
}
} break;
case 4: {
for(uint32_t i=0;i<p_frames;i++) {
rb[ (rb_write_pos<<2)+0 ] = read_buf[(i<<2)+0];
rb[ (rb_write_pos<<2)+1 ] = read_buf[(i<<2)+1];
rb[ (rb_write_pos<<2)+2 ] = read_buf[(i<<2)+2];
rb[ (rb_write_pos<<2)+3 ] = read_buf[(i<<2)+3];
rb_write_pos=(rb_write_pos+1)&rb_mask;
}
} break;
case 6: {
for(uint32_t i=0;i<p_frames;i++) {
rb[ (rb_write_pos*6)+0 ] = read_buf[(i*6)+0];
rb[ (rb_write_pos*6)+1 ] = read_buf[(i*6)+1];
rb[ (rb_write_pos*6)+2 ] = read_buf[(i*6)+2];
rb[ (rb_write_pos*6)+3 ] = read_buf[(i*6)+3];
rb[ (rb_write_pos*6)+4 ] = read_buf[(i*6)+4];
rb[ (rb_write_pos*6)+5 ] = read_buf[(i*6)+5];
rb_write_pos=(rb_write_pos+1)&rb_mask;
}
} break;
}
}
int get_channel_count() const;
Error setup(int p_channels, int p_src_mix_rate, int p_target_mix_rate, int p_buffer_msec, int p_minbuff_needed=-1);
void clear();
bool mix(int32_t *p_dest, int p_frames);
AudioRBResampler();
~AudioRBResampler();
};
#endif // AUDIO_RB_RESAMPLER_H