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freeswitch_rs/include/switch_resample.h

202 lines
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C

/*
* FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
* Copyright (C) 2005-2021, Anthony Minessale II <anthm@freeswitch.org>
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
*
* The Initial Developer of the Original Code is
* Anthony Minessale II <anthm@freeswitch.org>
* Portions created by the Initial Developer are Copyright (C)
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Anthony Minessale II <anthm@freeswitch.org>
*
*
* switch_resample.h
*
*/
/*! \file switch_resample.h
\brief Audio Resample Code
This module implements a generic interface for doing audio resampling it currently uses libresample but can be ported to
any resample library with a little effort. I decided against making this interface pluggable because there are not many
options in terms of resample libraries so it seemed like a waste but I did opt to frontend the interface in case a better
way comes along some day. =D
*/
#define switch_normalize_volume(x) if (x > 4) x = 4; if (x < -4) x = -4;
#define SWITCH_GRANULAR_VOLUME_MAX 50
#define switch_normalize_volume_granular(x) if (x > SWITCH_GRANULAR_VOLUME_MAX) x = SWITCH_GRANULAR_VOLUME_MAX; if (x < -SWITCH_GRANULAR_VOLUME_MAX) x = -SWITCH_GRANULAR_VOLUME_MAX;
#ifndef SWITCH_RESAMPLE_H
#define SWITCH_RESAMPLE_H
#define SWITCH_RESAMPLE_QUALITY 2
#include <switch.h>
SWITCH_BEGIN_EXTERN_C
/*!
\defgroup resamp Audio Resample Functions
\ingroup core1
\{
*/
/*! \brief An audio resampling handle */
typedef struct {
/*! a pointer to store the resampler object */
void *resampler;
/*! the rate to resample from in hz */
int from_rate;
/*! the rate to resample to in hz */
int to_rate;
/*! the factor to resample by (from / to) */
double factor;
double rfactor;
int16_t *to;
/*! the size of the to buffer used */
uint32_t to_len;
/*! the total size of the to buffer */
uint32_t to_size;
/*! the number of channels */
int channels;
} switch_audio_resampler_t;
/*!
\brief Prepare a new resampler handle
\param new_resampler NULL pointer to aim at the new handle
\param from_rate the rate to transfer from in hz
\param to_rate the rate to transfer to in hz
\param quality the quality desired
\return SWITCH_STATUS_SUCCESS if the handle was created
*/
SWITCH_DECLARE(switch_status_t) switch_resample_perform_create(switch_audio_resampler_t **new_resampler,
uint32_t from_rate, uint32_t to_rate, uint32_t to_size,
int quality, uint32_t channels, const char *file, const char *func, int line);
#define switch_resample_create(_n, _fr, _tr, _ts, _q, _c) switch_resample_perform_create(_n, _fr, _tr, _ts, _q, _c, __FILE__, __SWITCH_FUNC__, __LINE__)
/*!
\brief Destroy an existing resampler handle
\param resampler the resampler handle to destroy
*/
SWITCH_DECLARE(void) switch_resample_destroy(switch_audio_resampler_t **resampler);
/*!
\brief Resample one float buffer into another using specifications of a given handle
\param resampler the resample handle
\param src the source data
\param srclen the length of the source data
\return the used size of dst
*/
SWITCH_DECLARE(uint32_t) switch_resample_process(switch_audio_resampler_t *resampler, int16_t *src, uint32_t srclen);
/*!
\brief Convert an array of floats to an array of shorts
\param f the float buffer
\param s the short buffer
\param len the length of the buffers
\return the size of the converted buffer
*/
SWITCH_DECLARE(switch_size_t) switch_float_to_short(float *f, short *s, switch_size_t len);
/*!
\brief Convert an array of chars to an array of floats
\param c the char buffer
\param f the float buffer
\param len the length of the buffers
\return the size of the converted buffer
*/
SWITCH_DECLARE(int) switch_char_to_float(char *c, float *f, int len);
/*!
\brief Convert an array of floats to an array of chars
\param f an array of floats
\param c an array of chars
\param len the length of the buffers
\return the size of the converted buffer
*/
SWITCH_DECLARE(int) switch_float_to_char(float *f, char *c, int len);
/*!
\brief Convert an array of shorts to an array of floats
\param s an array of shorts
\param f an array of floats
\param len the size of the buffers
\return the size of the converted buffer
*/
SWITCH_DECLARE(int) switch_short_to_float(short *s, float *f, int len);
/*!
\brief Perform a byteswap on a buffer of 16 bit samples
\param buf an array of samples
\param len the size of the array
*/
SWITCH_DECLARE(void) switch_swap_linear(int16_t *buf, int len);
/*!
\brief Generate static noise
\param data the audio data buffer
\param samples the number of 2 byte samples
\param divisor the volume factor
*/
SWITCH_DECLARE(void) switch_generate_sln_silence(int16_t *data, uint32_t samples, uint32_t channels, uint32_t divisor);
/*!
\brief Change the volume of a signed linear audio frame
\param data the audio data
\param samples the number of 2 byte samples
\param vol the volume factor -4 -> 4
*/
SWITCH_DECLARE(void) switch_change_sln_volume(int16_t *data, uint32_t samples, int32_t vol);
/*!
\brief Change the volume of a signed linear audio frame with more granularity
\param data the audio data
\param samples the number of 2 byte samples
\param vol the volume factor -12 -> 12
*/
SWITCH_DECLARE(void) switch_change_sln_volume_granular(int16_t *data, uint32_t samples, int32_t vol);
///\}
SWITCH_DECLARE(uint32_t) switch_merge_sln(int16_t *data, uint32_t samples, int16_t *other_data, uint32_t other_samples, int channels);
SWITCH_DECLARE(uint32_t) switch_unmerge_sln(int16_t *data, uint32_t samples, int16_t *other_data, uint32_t other_samples, int channels);
SWITCH_DECLARE(void) switch_mux_channels(int16_t *data, switch_size_t samples, uint32_t orig_channels, uint32_t channels);
#define switch_resample_calc_buffer_size(_to, _from, _srclen) ((uint32_t)(((float)_to / (float)_from) * (float)_srclen) * 2)
SWITCH_DECLARE(void) switch_agc_set(switch_agc_t *agc, uint32_t energy_avg,
uint32_t low_energy_point, uint32_t margin, uint32_t change_factor, uint32_t period_len);
SWITCH_DECLARE(switch_status_t) switch_agc_create(switch_agc_t **agcP, uint32_t energy_avg,
uint32_t low_energy_point, uint32_t margin, uint32_t change_factor, uint32_t period_len);
SWITCH_DECLARE(void) switch_agc_destroy(switch_agc_t **agcP);
SWITCH_DECLARE(switch_status_t) switch_agc_feed(switch_agc_t *agc, int16_t *data, uint32_t samples, uint32_t channels);
SWITCH_DECLARE(void) switch_agc_set_energy_avg(switch_agc_t *agc, uint32_t energy_avg);
SWITCH_DECLARE(void) switch_agc_set_energy_low(switch_agc_t *agc, uint32_t low_energy_point);
SWITCH_DECLARE(void) switch_agc_set_token(switch_agc_t *agc, const char *token);
SWITCH_END_EXTERN_C
#endif
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