ref: 4b9ccf2823e0244c6ae7fcf4fe6a5d7e8d3868d8
dir: /stretch.h/
////////////////////////////////////////////////////////////////////////////
// **** AUDIO-STRETCH **** //
// Time Domain Harmonic Scaler //
// Copyright (c) 2022 David Bryant //
// All Rights Reserved. //
// Distributed under the BSD Software License (see license.txt) //
////////////////////////////////////////////////////////////////////////////
// stretch.h
// Time Domain Harmonic Compression and Expansion
//
// This library performs time domain harmonic scaling with pitch detection
// to stretch the timing of a 16-bit PCM signal (either mono or stereo) from
// 1/2 to 2 times its original length. This is done without altering any of
// its tonal characteristics.
//
// Use stereo (num_chans = 2), when both channels are from same source
// and should contain approximately similar content.
// For independent channels, prefer using multiple StretchHandle-instances.
// see https://github.com/dbry/audio-stretch/issues/6
#ifndef STRETCH_H
#define STRETCH_H
#include <stdint.h>
#define STRETCH_FAST_FLAG 0x1 // use "fast" version of period determination code
#define STRETCH_DUAL_FLAG 0x2 // cascade two instances (doubles usable ratio range)
#ifdef __cplusplus
extern "C" {
#endif
typedef void *StretchHandle;
StretchHandle stretch_init (int shortest_period, int longest_period, int num_chans, int flags);
int stretch_output_capacity (StretchHandle handle, int max_num_samples, float max_ratio);
int stretch_samples (StretchHandle handle, const int16_t *samples, int num_samples, int16_t *output, float ratio);
int stretch_flush (StretchHandle handle, int16_t *output);
void stretch_reset (StretchHandle handle);
void stretch_deinit (StretchHandle handle);
#ifdef __cplusplus
}
#endif
#endif