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MicroDexed/template_mixer.hpp

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// Taken from https://github.com/manicken/Audio/tree/templateMixer
/* Audio Library for Teensy 3.X
* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
*
* Development of this audio library was funded by PJRC.COM, LLC by sales of
* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
* open source software by purchasing Teensy or other PJRC products.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice, development funding notice, and this permission
* notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef template_mixer_h_
#define template_mixer_h_
#include "Arduino.h"
#include "AudioStream.h"
#define AudioMixer4 AudioMixer<4>
#if defined(__ARM_ARCH_7EM__)
#define MULTI_UNITYGAIN 65536
#define MULTI_UNITYGAIN_F 65536.0f
#define MAX_GAIN 32767.0f
#define MIN_GAIN -32767.0f
#define MULT_DATA_TYPE int32_t
#elif defined(KINETISL)
#define MULTI_UNITYGAIN 256
#define MULTI_UNITYGAIN_F 256.0f
#define MAX_GAIN 127.0f
#define MIN_GAIN -127.0f
#define MULT_DATA_TYPE int16_t
#endif
// because of the template use applyGain and applyGainThenAdd functions
// must be in this file and NOT in cpp file
#if defined(__ARM_ARCH_7EM__)
static void applyGain(int16_t *data, int32_t mult)
{
uint32_t *p = (uint32_t *)data;
const uint32_t *end = (uint32_t *)(data + AUDIO_BLOCK_SAMPLES);
do {
uint32_t tmp32 = *p; // read 2 samples from *data
int32_t val1 = signed_multiply_32x16b(mult, tmp32);
int32_t val2 = signed_multiply_32x16t(mult, tmp32);
val1 = signed_saturate_rshift(val1, 16, 0);
val2 = signed_saturate_rshift(val2, 16, 0);
*p++ = pack_16b_16b(val2, val1);
} while (p < end);
}
static void applyGainThenAdd(int16_t *data, const int16_t *in, int32_t mult)
{
uint32_t *dst = (uint32_t *)data;
const uint32_t *src = (uint32_t *)in;
const uint32_t *end = (uint32_t *)(data + AUDIO_BLOCK_SAMPLES);
if (mult == MULTI_UNITYGAIN) {
do {
uint32_t tmp32 = *dst;
*dst++ = signed_add_16_and_16(tmp32, *src++);
tmp32 = *dst;
*dst++ = signed_add_16_and_16(tmp32, *src++);
} while (dst < end);
} else {
do {
uint32_t tmp32 = *src++; // read 2 samples from *data
int32_t val1 = signed_multiply_32x16b(mult, tmp32);
int32_t val2 = signed_multiply_32x16t(mult, tmp32);
val1 = signed_saturate_rshift(val1, 16, 0);
val2 = signed_saturate_rshift(val2, 16, 0);
tmp32 = pack_16b_16b(val2, val1);
uint32_t tmp32b = *dst;
*dst++ = signed_add_16_and_16(tmp32, tmp32b);
} while (dst < end);
}
}
#elif defined(KINETISL)
static void applyGain(int16_t *data, int32_t mult)
{
const int16_t *end = data + AUDIO_BLOCK_SAMPLES;
do {
int32_t val = *data * mult;
*data++ = signed_saturate_rshift(val, 16, 0);
} while (data < end);
}
static void applyGainThenAdd(int16_t *dst, const int16_t *src, int32_t mult)
{
const int16_t *end = dst + AUDIO_BLOCK_SAMPLES;
if (mult == MULTI_UNITYGAIN) {
do {
int32_t val = *dst + *src++;
*dst++ = signed_saturate_rshift(val, 16, 0);
} while (dst < end);
} else {
do {
int32_t val = *dst + ((*src++ * mult) >> 8); // overflow possible??
*dst++ = signed_saturate_rshift(val, 16, 0);
} while (dst < end);
}
}
#endif
template <int NN> class AudioMixer : public AudioStream
{
public:
AudioMixer(void) : AudioStream(NN, inputQueueArray) {
for (int i=0; i<NN; i++) multiplier[i] = MULTI_UNITYGAIN;
}
void update();
/**
* this sets the individual gains
* @param channel
* @param gain
*/
void gain(unsigned int channel, float gain);
/**
* set all channels to specified gain
* @param gain
*/
void gain(float gain);
private:
MULT_DATA_TYPE multiplier[NN];
audio_block_t *inputQueueArray[NN];
};
// the following Forward declarations
// must be defined when we use template
// the compiler throws some warnings that should be errors otherwise
static inline int32_t signed_multiply_32x16b(int32_t a, uint32_t b);
static inline int32_t signed_multiply_32x16t(int32_t a, uint32_t b);
static inline int32_t signed_saturate_rshift(int32_t val, int bits, int rshift);
static inline uint32_t pack_16b_16b(int32_t a, int32_t b);
static inline uint32_t signed_add_16_and_16(uint32_t a, uint32_t b);
template <int NN> void AudioMixer<NN>::gain(unsigned int channel, float gain) {
if (channel >= NN) return;
if (gain > MAX_GAIN) gain = MAX_GAIN;
else if (gain < MIN_GAIN) gain = MIN_GAIN;
multiplier[channel] = gain * MULTI_UNITYGAIN_F; // TODO: proper roundoff?
}
template <int NN> void AudioMixer<NN>::gain(float gain) {
for (int i = 0; i < NN; i++) {
if (gain > MAX_GAIN) gain = MAX_GAIN;
else if (gain < MIN_GAIN) gain = MIN_GAIN;
multiplier[i] = gain * MULTI_UNITYGAIN_F; // TODO: proper roundoff?
}
}
template <int NN> void AudioMixer<NN>::update() {
audio_block_t *in, *out=NULL;
unsigned int channel;
for (channel=0; channel < NN; channel++) {
if (!out) {
out = receiveWritable(channel);
if (out) {
int32_t mult = multiplier[channel];
if (mult != MULTI_UNITYGAIN) applyGain(out->data, mult);
}
} else {
in = receiveReadOnly(channel);
if (in) {
applyGainThenAdd(out->data, in->data, multiplier[channel]);
release(in);
}
}
}
if (out) {
transmit(out);
release(out);
}
}
#endif