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Add a new algorithm to calculate the true-peak. It implements the Whittaker- Shannon interpolation from four samples to create 4 intermediate samples (5 x oversampling) inbetween the middle two samples. With 4 samples and 4 intermediate samples the algorithm can be implemented as a 4x4 vector-matrix cross product, which is ideal for SSE. I've also replaced the sample-peak algorithm using SSE as well to improve performance. Closes obsproject/obs-studio#1189
279 lines
8.7 KiB
C
279 lines
8.7 KiB
C
/*
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Copyright (C) 2014 by Leonhard Oelke <leonhard@in-verted.de>
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include "obs.h"
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/**
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* @file
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* @brief header for audio controls
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*
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* @brief Audio controls for use in GUIs
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*/
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#ifdef __cplusplus
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extern "C" {
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#endif
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/**
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* @brief Fader types
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*/
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enum obs_fader_type {
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/**
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* @brief A simple cubic fader for controlling audio levels
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*
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* This is a very common type of software fader since it yields good
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* results while being quite performant.
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* The input value is mapped to mul values with the simple formula x^3.
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*/
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OBS_FADER_CUBIC,
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/**
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* @brief A fader compliant to IEC 60-268-18
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*
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* This type of fader has several segments with different slopes that
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* map deflection linearly to dB values. The segments are defined as
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* in the following table:
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*
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@code
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Deflection | Volume
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------------------------------------------
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[ 100 %, 75 % ] | [ 0 dB, -9 dB ]
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[ 75 %, 50 % ] | [ -9 dB, -20 dB ]
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[ 50 %, 30 % ] | [ -20 dB, -30 dB ]
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[ 30 %, 15 % ] | [ -30 dB, -40 dB ]
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[ 15 %, 7.5 % ] | [ -40 dB, -50 dB ]
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[ 7.5 %, 2.5 % ] | [ -50 dB, -60 dB ]
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[ 2.5 %, 0 % ] | [ -60 dB, -inf dB ]
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@endcode
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*/
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OBS_FADER_IEC,
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/**
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* @brief Logarithmic fader
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*/
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OBS_FADER_LOG
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};
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/**
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* @brief Peak meter types
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*/
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enum obs_peak_meter_type {
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/**
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* @brief A simple peak meter measuring the maximum of all samples.
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*
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* This was a very common type of peak meter used for audio, but
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* is not very accurate with regards to further audio processing.
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*/
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SAMPLE_PEAK_METER,
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/**
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* @brief An accurate peak meter measure the maximum of inter-samples.
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*
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* This meter is more computational intensive due to 4x oversampling
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* to determine the true peak to an accuracy of +/- 0.5 dB.
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*/
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TRUE_PEAK_METER
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};
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/**
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* @brief Create a fader
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* @param type the type of the fader
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* @return pointer to the fader object
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*
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* A fader object is used to map input values from a gui element to dB and
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* subsequently multiplier values used by libobs to mix audio.
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* The current "position" of the fader is internally stored as dB value.
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*/
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EXPORT obs_fader_t *obs_fader_create(enum obs_fader_type type);
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/**
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* @brief Destroy a fader
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* @param fader pointer to the fader object
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*
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* Destroy the fader and free all related data
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*/
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EXPORT void obs_fader_destroy(obs_fader_t *fader);
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/**
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* @brief Set the fader dB value
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* @param fader pointer to the fader object
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* @param db new dB value
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* @return true if value was set without clamping
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*/
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EXPORT bool obs_fader_set_db(obs_fader_t *fader, const float db);
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/**
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* @brief Get the current fader dB value
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* @param fader pointer to the fader object
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* @return current fader dB value
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*/
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EXPORT float obs_fader_get_db(obs_fader_t *fader);
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/**
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* @brief Set the fader value from deflection
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* @param fader pointer to the fader object
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* @param def new deflection
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* @return true if value was set without clamping
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*
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* This sets the new fader value from the supplied deflection, in case the
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* resulting value was clamped due to limits this function will return false.
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* The deflection is typically in the range [0.0, 1.0] but may be higher in
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* order to provide some amplification. In order for this to work the high dB
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* limit has to be set.
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*/
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EXPORT bool obs_fader_set_deflection(obs_fader_t *fader, const float def);
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/**
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* @brief Get the current fader deflection
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* @param fader pointer to the fader object
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* @return current fader deflection
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*/
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EXPORT float obs_fader_get_deflection(obs_fader_t *fader);
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/**
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* @brief Set the fader value from multiplier
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* @param fader pointer to the fader object
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* @return true if the value was set without clamping
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*/
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EXPORT bool obs_fader_set_mul(obs_fader_t *fader, const float mul);
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/**
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* @brief Get the current fader multiplier value
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* @param fader pointer to the fader object
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* @return current fader multiplier
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*/
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EXPORT float obs_fader_get_mul(obs_fader_t *fader);
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/**
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* @brief Attach the fader to a source
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* @param fader pointer to the fader object
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* @param source pointer to the source object
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* @return true on success
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*
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* When the fader is attached to a source it will automatically sync it's state
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* to the volume of the source.
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*/
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EXPORT bool obs_fader_attach_source(obs_fader_t *fader, obs_source_t *source);
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/**
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* @brief Detach the fader from the currently attached source
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* @param fader pointer to the fader object
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*/
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EXPORT void obs_fader_detach_source(obs_fader_t *fader);
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typedef void (*obs_fader_changed_t)(void *param, float db);
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EXPORT void obs_fader_add_callback(obs_fader_t *fader,
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obs_fader_changed_t callback, void *param);
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EXPORT void obs_fader_remove_callback(obs_fader_t *fader,
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obs_fader_changed_t callback, void *param);
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/**
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* @brief Create a volume meter
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* @param type the mapping type to use for the volume meter
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* @return pointer to the volume meter object
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*
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* A volume meter object is used to prepare the sound levels reported by audio
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* sources for display in a GUI.
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* It will automatically take source volume into account and map the levels
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* to a range [0.0f, 1.0f].
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*/
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EXPORT obs_volmeter_t *obs_volmeter_create(enum obs_fader_type type);
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/**
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* @brief Destroy a volume meter
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* @param volmeter pointer to the volmeter object
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*
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* Destroy the volume meter and free all related data
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*/
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EXPORT void obs_volmeter_destroy(obs_volmeter_t *volmeter);
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/**
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* @brief Attach the volume meter to a source
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* @param volmeter pointer to the volume meter object
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* @param source pointer to the source object
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* @return true on success
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*
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* When the volume meter is attached to a source it will start to listen to
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* volume updates on the source and after preparing the data emit its own
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* signal.
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*/
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EXPORT bool obs_volmeter_attach_source(obs_volmeter_t *volmeter,
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obs_source_t *source);
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/**
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* @brief Detach the volume meter from the currently attached source
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* @param volmeter pointer to the volume meter object
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*/
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EXPORT void obs_volmeter_detach_source(obs_volmeter_t *volmeter);
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/**
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* @brief Set the peak meter type for the volume meter
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* @param volmeter pointer to the volume meter object
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* @param peak_meter_type set if true-peak needs to be measured.
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*/
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EXPORT void obs_volmeter_set_peak_meter_type(obs_volmeter_t *volmeter,
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enum obs_peak_meter_type peak_meter_type);
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/**
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* @brief Set the update interval for the volume meter
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* @param volmeter pointer to the volume meter object
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* @param ms update interval in ms
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*
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* This sets the update interval in milliseconds that should be processed before
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* the resulting values are emitted by the levels_updated signal. The resulting
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* number of audio samples is rounded to an integer.
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*
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* Please note that due to way obs does receive audio data from the sources
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* this is no hard guarantee for the timing of the signal itself. When the
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* volume meter receives a chunk of data that is multiple the size of the sample
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* interval, all data will be sampled and the values updated accordingly, but
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* only the signal for the last segment is actually emitted.
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* On the other hand data might be received in a way that will cause the signal
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* to be emitted in shorter intervals than specified here under some
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* circumstances.
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*/
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EXPORT void obs_volmeter_set_update_interval(obs_volmeter_t *volmeter,
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const unsigned int ms);
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/**
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* @brief Get the update interval currently used for the volume meter
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* @param volmeter pointer to the volume meter object
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* @return update interval in ms
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*/
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EXPORT unsigned int obs_volmeter_get_update_interval(obs_volmeter_t *volmeter);
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/**
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* @brief Get the number of channels which are configured for this source.
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* @param volmeter pointer to the volume meter object
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*/
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EXPORT int obs_volmeter_get_nr_channels(obs_volmeter_t *volmeter);
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typedef void (*obs_volmeter_updated_t)(void *param,
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const float magnitude[MAX_AUDIO_CHANNELS],
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const float peak[MAX_AUDIO_CHANNELS],
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const float input_peak[MAX_AUDIO_CHANNELS]);
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EXPORT void obs_volmeter_add_callback(obs_volmeter_t *volmeter,
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obs_volmeter_updated_t callback, void *param);
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EXPORT void obs_volmeter_remove_callback(obs_volmeter_t *volmeter,
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obs_volmeter_updated_t callback, void *param);
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#ifdef __cplusplus
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}
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#endif
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