/*----------------------------------------------------------------------------
*
* File:
* eas_reverbdata.h
*
* Contents and purpose:
* Contains the prototypes for the Reverb effect.
*
*
* Copyright Sonic Network Inc. 2006
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*----------------------------------------------------------------------------
* Revision Control:
* $Revision: 499 $
* $Date: 2006-12-11 16:07:20 -0800 (Mon, 11 Dec 2006) $
*----------------------------------------------------------------------------
*/
#ifndef _EAS_REVERBDATA_H
#define _EAS_REVERBDATA_H
#include "eas_types.h"
#include "eas_audioconst.h"
/*------------------------------------
* defines
*------------------------------------
*/
/*
CIRCULAR() calculates the array index using modulo arithmetic.
The "trick" is that modulo arithmetic is simplified by masking
the effective address where the mask is (2^n)-1. This only works
if the buffer size is a power of two.
*/
#define CIRCULAR(base,offset,size) (EAS_U32)( \
( \
((EAS_I32)(base)) + ((EAS_I32)(offset)) \
) \
& size \
)
/* reverb parameters are updated every 2^(REVERB_UPDATE_PERIOD_IN_BITS) samples */
#if defined (_SAMPLE_RATE_8000)
#define REVERB_UPDATE_PERIOD_IN_BITS 5
#define REVERB_BUFFER_SIZE_IN_SAMPLES 2048
#elif defined (_SAMPLE_RATE_16000)
#define REVERB_UPDATE_PERIOD_IN_BITS 6
#define REVERB_BUFFER_SIZE_IN_SAMPLES 4096
#elif defined (_SAMPLE_RATE_22050)
#define REVERB_UPDATE_PERIOD_IN_BITS 7
#define REVERB_BUFFER_SIZE_IN_SAMPLES 4096
#elif defined (_SAMPLE_RATE_32000)
#define REVERB_UPDATE_PERIOD_IN_BITS 7
#define REVERB_BUFFER_SIZE_IN_SAMPLES 8192
#elif defined (_SAMPLE_RATE_44100)
#define REVERB_UPDATE_PERIOD_IN_BITS 8
#define REVERB_BUFFER_SIZE_IN_SAMPLES 8192
#elif defined (_SAMPLE_RATE_48000)
#define REVERB_UPDATE_PERIOD_IN_BITS 8
#define REVERB_BUFFER_SIZE_IN_SAMPLES 8192
#endif
// Define a mask for circular addressing, so that array index
// can wraparound and stay in array boundary of 0, 1, ..., (buffer size -1)
// The buffer size MUST be a power of two
#define REVERB_BUFFER_MASK (REVERB_BUFFER_SIZE_IN_SAMPLES -1)
#define REVERB_MAX_ROOM_TYPE 4 // any room numbers larger than this are invalid
#define REVERB_MAX_NUM_REFLECTIONS 5 // max num reflections per channel
/* synth parameters are updated every SYNTH_UPDATE_PERIOD_IN_SAMPLES */
#define REVERB_UPDATE_PERIOD_IN_SAMPLES (EAS_I32)(0x1L << REVERB_UPDATE_PERIOD_IN_BITS)
/*
calculate the update counter by bitwise ANDING with this value to
generate a 2^n modulo value
*/
#define REVERB_MODULO_UPDATE_PERIOD_IN_SAMPLES (EAS_I32)(REVERB_UPDATE_PERIOD_IN_SAMPLES -1)
/* synth parameters are updated every SYNTH_UPDATE_PERIOD_IN_SECONDS seconds */
#define REVERB_UPDATE_PERIOD_IN_SECONDS (REVERB_UPDATE_PERIOD_IN_SAMPLES / _OUTPUT_SAMPLE_RATE)
// xfade parameters
#define REVERB_XFADE_PERIOD_IN_SECONDS (100.0 / 1000.0) // xfade once every this many seconds
#define REVERB_XFADE_PERIOD_IN_SAMPLES (REVERB_XFADE_PERIOD_IN_SECONDS * _OUTPUT_SAMPLE_RATE)
#define REVERB_XFADE_PHASE_INCREMENT (EAS_I16)(65536 / ((EAS_I16)REVERB_XFADE_PERIOD_IN_SAMPLES/(EAS_I16)REVERB_UPDATE_PERIOD_IN_SAMPLES))
/**********/
/* the entire synth uses various flags in a bit field */
/* if flag is set, synth reset has been requested */
#define REVERB_FLAG_RESET_IS_REQUESTED 0x01 /* bit 0 */
#define MASK_REVERB_RESET_IS_REQUESTED 0x01
#define MASK_REVERB_RESET_IS_NOT_REQUESTED (EAS_U32)(~MASK_REVERB_RESET_IS_REQUESTED)
/*
by default, we always want to update ALL channel parameters
when we reset the synth (e.g., during GM ON)
*/
#define DEFAULT_REVERB_FLAGS 0x0
/* coefficients for generating sin, cos */
#define REVERB_PAN_G2 4294940151 /* -0.82842712474619 = 2 - 4/sqrt(2) */
/*
EAS_I32 nPanG1 = +1.0 for sin
EAS_I32 nPanG1 = -1.0 for cos
*/
#define REVERB_PAN_G0 23170 /* 0.707106781186547 = 1/sqrt(2) */
/*************************************************************/
// define the input injection points
#define GUARD 5 // safety guard of this many samples
#define MAX_AP_TIME (double) (20.0/1000.0) // delay time in milliseconds
#define MAX_DELAY_TIME (double) (65.0/1000.0) // delay time in milliseconds
#define MAX_AP_SAMPLES (int)(((double) MAX_AP_TIME) * ((double) _OUTPUT_SAMPLE_RATE))
#define MAX_DELAY_SAMPLES (int)(((double) MAX_DELAY_TIME) * ((double) _OUTPUT_SAMPLE_RATE))
#define AP0_IN 0
#define AP1_IN (AP0_IN + MAX_AP_SAMPLES + GUARD)
#define DELAY0_IN (AP1_IN + MAX_AP_SAMPLES + GUARD)
#define DELAY1_IN (DELAY0_IN + MAX_DELAY_SAMPLES + GUARD)
// Define the max offsets for the end points of each section
// i.e., we don't expect a given section's taps to go beyond
// the following limits
#define AP0_OUT (AP0_IN + MAX_AP_SAMPLES -1)
#define AP1_OUT (AP1_IN + MAX_AP_SAMPLES -1)
#define DELAY0_OUT (DELAY0_IN + MAX_DELAY_SAMPLES -1)
#define DELAY1_OUT (DELAY1_IN + MAX_DELAY_SAMPLES -1)
#define REVERB_DEFAULT_ROOM_NUMBER 1 // default preset number
#define DEFAULT_AP0_LENGTH (int)(((double) (17.0/1000.0)) * ((double) _OUTPUT_SAMPLE_RATE))
#define DEFAULT_AP0_GAIN 19400
#define DEFAULT_AP1_LENGTH (int)(((double) (16.5/1000.0)) * ((double) _OUTPUT_SAMPLE_RATE))
#define DEFAULT_AP1_GAIN -19400
#define REVERB_DEFAULT_WET 32767
#define REVERB_DEFAULT_DRY 0
#define EAS_REVERB_WET_MAX 32767
#define EAS_REVERB_WET_MIN 0
#define EAS_REVERB_DRY_MAX 32767
#define EAS_REVERB_DRY_MIN 0
/* parameters for each allpass */
typedef struct
{
EAS_U16 m_zApOut; // delay offset for ap out
EAS_I16 m_nApGain; // gain for ap
EAS_U16 m_zApIn; // delay offset for ap in
} S_ALLPASS_OBJECT;
/* parameters for each allpass */
typedef struct
{
EAS_PCM m_zLpf; // actual state variable, not a length
EAS_I16 m_nLpfFwd; // lpf forward gain
EAS_I16 m_nLpfFbk; // lpf feedback gain
EAS_U16 m_zDelay[REVERB_MAX_NUM_REFLECTIONS]; // delay offset for ap out
EAS_I16 m_nGain[REVERB_MAX_NUM_REFLECTIONS]; // gain for ap
} S_EARLY_REFLECTION_OBJECT;
//demo
typedef struct
{
EAS_I16 m_nLpfFbk;
EAS_I16 m_nLpfFwd;
EAS_I16 m_nEarly;
EAS_I16 m_nWet;
EAS_I16 m_nDry;
EAS_I16 m_nEarlyL_LpfFbk;
EAS_I16 m_nEarlyL_LpfFwd;
EAS_I16 m_nEarlyL_Delay0; //8
EAS_I16 m_nEarlyL_Gain0;
EAS_I16 m_nEarlyL_Delay1;
EAS_I16 m_nEarlyL_Gain1;
EAS_I16 m_nEarlyL_Delay2;
EAS_I16 m_nEarlyL_Gain2;
EAS_I16 m_nEarlyL_Delay3;
EAS_I16 m_nEarlyL_Gain3;
EAS_I16 m_nEarlyL_Delay4;
EAS_I16 m_nEarlyL_Gain4;
EAS_I16 m_nEarlyR_Delay0; //18
EAS_I16 m_nEarlyR_Gain0;
EAS_I16 m_nEarlyR_Delay1;
EAS_I16 m_nEarlyR_Gain1;
EAS_I16 m_nEarlyR_Delay2;
EAS_I16 m_nEarlyR_Gain2;
EAS_I16 m_nEarlyR_Delay3;
EAS_I16 m_nEarlyR_Gain3;
EAS_I16 m_nEarlyR_Delay4;
EAS_I16 m_nEarlyR_Gain4;
EAS_U16 m_nMaxExcursion; //28
EAS_I16 m_nXfadeInterval;
EAS_I16 m_nAp0_ApGain; //30
EAS_I16 m_nAp0_ApOut;
EAS_I16 m_nAp1_ApGain;
EAS_I16 m_nAp1_ApOut;
EAS_I16 m_rfu4;
EAS_I16 m_rfu5;
EAS_I16 m_rfu6;
EAS_I16 m_rfu7;
EAS_I16 m_rfu8;
EAS_I16 m_rfu9;
EAS_I16 m_rfu10; //43
} S_REVERB_PRESET;
typedef struct
{
S_REVERB_PRESET m_sPreset[REVERB_MAX_ROOM_TYPE]; //array of presets
} S_REVERB_PRESET_BANK;
/* parameters for each reverb */
typedef struct
{
/* controls entire reverb playback volume */
/* to conserve memory, use the MSB and ignore the LSB */
EAS_U8 m_nMasterVolume;
/* update counter keeps track of when synth params need updating */
/* only needs to be as large as REVERB_UPDATE_PERIOD_IN_SAMPLES */
EAS_I16 m_nUpdateCounter;
EAS_U16 m_nMinSamplesToAdd; /* ComputeReverb() generates this many samples */
EAS_U8 m_nFlags; /* misc flags/bit fields */
EAS_PCM *m_pOutputBuffer;
EAS_PCM *m_pInputBuffer;
EAS_U16 m_nNumSamplesInOutputBuffer;
EAS_U16 m_nNumSamplesInInputBuffer;
EAS_U16 m_nNumInputSamplesRead; // if m_nNumInputSamplesRead >= NumSamplesInInputBuffer
// then get a new input buffer
EAS_PCM *m_pNextInputSample;
EAS_U16 m_nBaseIndex; // base index for circular buffer
// reverb delay line offsets, allpass parameters, etc:
EAS_PCM m_nRevOutFbkR; // combine feedback reverb right out with dry left in
S_ALLPASS_OBJECT m_sAp0; // allpass 0 (left channel)
EAS_U16 m_zD0In; // delay offset for delay line D0 in
EAS_PCM m_nRevOutFbkL; // combine feedback reverb left out with dry right in
S_ALLPASS_OBJECT m_sAp1; // allpass 1 (right channel)
EAS_U16 m_zD1In; // delay offset for delay line D1 in
// delay output taps, notice criss cross order
EAS_U16 m_zD0Self; // self feeds forward d0 --> d0
EAS_U16 m_zD1Cross; // cross feeds across d1 --> d0
EAS_PCM m_zLpf0; // actual state variable, not a length
EAS_U16 m_zD1Self; // self feeds forward d1 --> d1
EAS_U16 m_zD0Cross; // cross feeds across d0 --> d1
EAS_PCM m_zLpf1; // actual state variable, not a length
EAS_I16 m_nSin; // gain for self taps
EAS_I16 m_nCos; // gain for cross taps
EAS_I16 m_nSinIncrement; // increment for gain
EAS_I16 m_nCosIncrement; // increment for gain
EAS_I16 m_nLpfFwd; // lpf forward gain (includes scaling for mixer)
EAS_I16 m_nLpfFbk; // lpf feedback gain
EAS_U16 m_nXfadeInterval; // update/xfade after this many samples
EAS_U16 m_nXfadeCounter; // keep track of when to xfade
EAS_I16 m_nPhase; // -1 <= m_nPhase < 1
// but during sin,cos calculations
// use m_nPhase/2
EAS_I16 m_nPhaseIncrement; // add this to m_nPhase each frame
EAS_I16 m_nNoise; // random noise sample
EAS_U16 m_nMaxExcursion; // the taps can excurse +/- this amount
EAS_BOOL m_bUseNoise; // if EAS_TRUE, use noise as input signal
EAS_BOOL m_bBypass; // if EAS_TRUE, then bypass reverb and copy input to output
EAS_I16 m_nCurrentRoom; // preset number for current room
EAS_I16 m_nNextRoom; // preset number for next room
EAS_I16 m_nWet; // gain for wet (processed) signal
EAS_I16 m_nDry; // gain for dry (unprocessed) signal
EAS_I16 m_nEarly; // gain for early (widen) signal
S_EARLY_REFLECTION_OBJECT m_sEarlyL; // left channel early reflections
S_EARLY_REFLECTION_OBJECT m_sEarlyR; // right channel early reflections
EAS_PCM m_nDelayLine[REVERB_BUFFER_SIZE_IN_SAMPLES]; // one large delay line for all reverb elements
S_REVERB_PRESET pPreset;
S_REVERB_PRESET_BANK m_sPreset;
//EAS_I8 preset;
} S_REVERB_OBJECT;
/*------------------------------------
* prototypes
*------------------------------------
*/
/*----------------------------------------------------------------------------
* ReverbUpdateXfade
*----------------------------------------------------------------------------
* Purpose:
* Update the xfade parameters as required
*
* Inputs:
* nNumSamplesToAdd - number of samples to write to buffer
*
* Outputs:
*
*
* Side Effects:
* - xfade parameters will be changed
*
*----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbUpdateXfade(S_REVERB_OBJECT* pReverbData, EAS_INT nNumSamplesToAdd);
/*----------------------------------------------------------------------------
* ReverbCalculateNoise
*----------------------------------------------------------------------------
* Purpose:
* Calculate a noise sample and limit its value
*
* Inputs:
* nMaxExcursion - noise value is limited to this value
* pnNoise - return new noise sample in this (not limited)
*
* Outputs:
* new limited noise value
*
* Side Effects:
* - *pnNoise noise value is updated
*
*----------------------------------------------------------------------------
*/
static EAS_U16 ReverbCalculateNoise(EAS_U16 nMaxExcursion, EAS_I16 *pnNoise);
/*----------------------------------------------------------------------------
* ReverbCalculateSinCos
*----------------------------------------------------------------------------
* Purpose:
* Calculate a new sin and cosine value based on the given phase
*
* Inputs:
* nPhase - phase angle
* pnSin - input old value, output new value
* pnCos - input old value, output new value
*
* Outputs:
*
* Side Effects:
* - *pnSin, *pnCos are updated
*
*----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbCalculateSinCos(EAS_I16 nPhase, EAS_I16 *pnSin, EAS_I16 *pnCos);
/*----------------------------------------------------------------------------
* Reverb
*----------------------------------------------------------------------------
* Purpose:
* apply reverb to the given signal
*
* Inputs:
* nNu
* pnSin - input old value, output new value
* pnCos - input old value, output new value
*
* Outputs:
* number of samples actually reverberated
*
* Side Effects:
*
*----------------------------------------------------------------------------
*/
static EAS_RESULT Reverb(S_REVERB_OBJECT* pReverbData, EAS_INT nNumSamplesToAdd, EAS_PCM *pOutputBuffer, EAS_PCM *pInputBuffer);
/*----------------------------------------------------------------------------
* ReverbReadInPresets()
*----------------------------------------------------------------------------
* Purpose: sets global reverb preset bank to defaults
*
* Inputs:
*
* Outputs:
*
*----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbReadInPresets(S_REVERB_OBJECT* pReverbData);
/*----------------------------------------------------------------------------
* ReverbUpdateRoom
*----------------------------------------------------------------------------
* Purpose:
* Update the room's preset parameters as required
*
* Inputs:
*
* Outputs:
*
*
* Side Effects:
* - reverb paramters (fbk, fwd, etc) will be changed
* - m_nCurrentRoom := m_nNextRoom
*----------------------------------------------------------------------------
*/
static EAS_RESULT ReverbUpdateRoom(S_REVERB_OBJECT* pReverbData);
#endif /* #ifndef _EAS_REVERBDATA_H */