/* * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application * Copyright (C) 2005-2021, Anthony Minessale II * * 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 * Portions created by the Initial Developer are Copyright (C) * the Initial Developer. All Rights Reserved. * * Contributor(s): * * Anthony Minessale II * * * 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_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 /* For Emacs: * Local Variables: * mode:c * indent-tabs-mode:t * tab-width:4 * c-basic-offset:4 * End: * For VIM: * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet: */