Genesis-Plus-GX/core/sound/blip_buf.h

86 lines
3.0 KiB
C

/** Sample buffer that resamples from input clock rate to output sample rate \file */
/* blip_buf $vers */
#ifndef BLIP_BUF_H
#define BLIP_BUF_H
#ifdef __cplusplus
extern "C" {
#endif
/** First parameter of most functions is blip_t*, or const blip_t* if nothing
is changed. */
typedef struct blip_t blip_t;
/** Creates new buffer that can hold at most sample_count samples. Sets rates
so that there are blip_max_ratio clocks per sample. Returns pointer to new
buffer, or NULL if insufficient memory. */
blip_t* blip_new( int sample_count );
/** Sets approximate input clock rate and output sample rate. For every
clock_rate input clocks, approximately sample_rate samples are generated. */
void blip_set_rates( blip_t*, double clock_rate, double sample_rate );
enum { /** Maximum clock_rate/sample_rate ratio. For a given sample_rate,
clock_rate must not be greater than sample_rate*blip_max_ratio. */
blip_max_ratio = 1 << 20 };
/** Clears entire buffer. Afterwards, blip_samples_avail() == 0. */
void blip_clear( blip_t* );
#ifndef BLIP_MONO
/** Adds positive/negative deltas into stereo buffers at specified clock time. */
void blip_add_delta( blip_t*, unsigned time, int delta_l, int delta_r );
/** Same as blip_add_delta(), but uses faster, lower-quality synthesis. */
void blip_add_delta_fast( blip_t*, unsigned int clock_time, int delta_l, int delta_r );
#else
/** Adds positive/negative delta into buffer at specified clock time. */
void blip_add_delta( blip_t*, unsigned int clock_time, int delta );
/** Same as blip_add_delta(), but uses faster, lower-quality synthesis. */
void blip_add_delta_fast( blip_t*, unsigned int clock_time, int delta );
#endif
/** Length of time frame, in clocks, needed to make sample_count additional
samples available. */
int blip_clocks_needed( const blip_t*, int sample_count );
enum { /** Maximum number of samples that can be generated from one time frame. */
blip_max_frame = 4000 };
/** Makes input clocks before clock_duration available for reading as output
samples. Also begins new time frame at clock_duration, so that clock time 0 in
the new time frame specifies the same clock as clock_duration in the old time
frame specified. Deltas can have been added slightly past clock_duration (up to
however many clocks there are in two output samples). */
void blip_end_frame( blip_t*, unsigned int clock_duration );
/** Number of buffered samples available for reading. */
int blip_samples_avail( const blip_t* );
/** Reads and removes at most 'count' samples and writes them to to every other
element of 'out', allowing easy interleaving of two buffers into a stereo sample
stream. Outputs 16-bit signed samples. Returns number of samples actually read. */
int blip_read_samples( blip_t*, short out [], int count);
/* Same as above function except sample is mixed from three blip buffers source */
int blip_mix_samples( blip_t* m1, blip_t* m2, blip_t* m3, short out [], int count);
/** Frees buffer. No effect if NULL is passed. */
void blip_delete( blip_t* );
/* Deprecated */
typedef blip_t blip_buffer_t;
#ifdef __cplusplus
}
#endif
#endif