83 lines
2.6 KiB
C++
83 lines
2.6 KiB
C++
/* Audio Library for Teensy 3.X
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* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
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*
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* Development of this audio library was funded by PJRC.COM, LLC by sales of
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* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
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* open source software by purchasing Teensy or other PJRC products.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice, development funding notice, and this permission
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* notice shall be included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <Arduino.h>
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#include "analyze_rms.h"
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#include "utility/dspinst.h"
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void AudioAnalyzeRMS::update(void)
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{
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audio_block_t *block = receiveReadOnly();
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if (!block) {
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count++;
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return;
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}
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#if defined(__ARM_ARCH_7EM__)
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uint32_t *p = (uint32_t *)(block->data);
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uint32_t *end = p + AUDIO_BLOCK_SAMPLES/2;
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int64_t sum = accum;
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do {
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uint32_t n1 = *p++;
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uint32_t n2 = *p++;
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uint32_t n3 = *p++;
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uint32_t n4 = *p++;
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sum = multiply_accumulate_16tx16t_add_16bx16b(sum, n1, n1);
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sum = multiply_accumulate_16tx16t_add_16bx16b(sum, n2, n2);
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sum = multiply_accumulate_16tx16t_add_16bx16b(sum, n3, n3);
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sum = multiply_accumulate_16tx16t_add_16bx16b(sum, n4, n4);
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} while (p < end);
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accum = sum;
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count++;
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#else
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int16_t *p = block->data;
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int16_t *end = p + AUDIO_BLOCK_SAMPLES;
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int64_t sum = accum;
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do {
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int32_t n = *p++;
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sum += n * n;
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} while (p < end);
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accum = sum;
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count++;
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#endif
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release(block);
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}
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float AudioAnalyzeRMS::read(void)
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{
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__disable_irq();
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int64_t sum = accum;
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accum = 0;
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uint32_t num = count;
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count = 0;
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__enable_irq();
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float meansq = sum / (num * AUDIO_BLOCK_SAMPLES);
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// TODO: shift down to 32 bits and use sqrt_uint32
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// but is that really any more efficient?
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return sqrtf(meansq) / 32767.0;
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}
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