15b4baba28
- minimize RAM usage of all components - use both IRAM and DRAM in player component so we can buffer up to 1s on modules without SPI RAM - support fragemented pcm chunks so we can use all available RAM if there isn't a big enough block available but still enough HEAP - reinclude all components from jorgen's master branch - add custom i2s driver to get a precise timing of initial sync - change wrong usage of esp_timer for latency measurement of snapcast protocol - add player component
121 lines
3.2 KiB
C
121 lines
3.2 KiB
C
/*
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* MedianFilter.c
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*
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* Created on: May 19, 2018
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* Author: alexandru.bogdan
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* Editor: Carlos Derseher
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*
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* original source code:
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* https://github.com/accabog/MedianFilter
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*/
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/**
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* This Module expects odd numbers of buffer lengths!!!
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*/
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#include <stdint.h>
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#include "MedianFilter.h"
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/**
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*
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*/
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int MEDIANFILTER_Init(sMedianFilter_t *medianFilter) {
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if (medianFilter && medianFilter->medianBuffer &&
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(medianFilter->numNodes % 2) && (medianFilter->numNodes > 1)) {
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// initialize buffer nodes
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for (unsigned int i = 0; i < medianFilter->numNodes; i++) {
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medianFilter->medianBuffer[i].value = 0;
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medianFilter->medianBuffer[i].nextAge =
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&medianFilter->medianBuffer[(i + 1) % medianFilter->numNodes];
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medianFilter->medianBuffer[i].nextValue =
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&medianFilter->medianBuffer[(i + 1) % medianFilter->numNodes];
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medianFilter->medianBuffer[(i + 1) % medianFilter->numNodes].prevValue =
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&medianFilter->medianBuffer[i];
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}
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// initialize heads
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medianFilter->ageHead = medianFilter->medianBuffer;
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medianFilter->valueHead = medianFilter->medianBuffer;
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medianFilter->medianHead =
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&medianFilter->medianBuffer[medianFilter->numNodes / 2];
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medianFilter->bufferCnt = 0;
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return 0;
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}
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return -1;
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}
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/**
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*
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*/
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int64_t MEDIANFILTER_Insert(sMedianFilter_t *medianFilter, int64_t sample) {
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unsigned int i;
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sMedianNode_t *newNode, *it;
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if (medianFilter->ageHead ==
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medianFilter->valueHead) { // if oldest node is also the smallest node,
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// increment value head
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medianFilter->valueHead = medianFilter->valueHead->nextValue;
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}
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if ((medianFilter->ageHead == medianFilter->medianHead) ||
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(medianFilter->ageHead->value >
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medianFilter->medianHead->value)) { // prepare for median correction
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medianFilter->medianHead = medianFilter->medianHead->prevValue;
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}
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// replace age head with new sample
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newNode = medianFilter->ageHead;
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newNode->value = sample;
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// remove age head from list
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medianFilter->ageHead->nextValue->prevValue =
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medianFilter->ageHead->prevValue;
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medianFilter->ageHead->prevValue->nextValue =
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medianFilter->ageHead->nextValue;
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// increment age head
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medianFilter->ageHead = medianFilter->ageHead->nextAge;
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// find new node position
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it = medianFilter->valueHead; // set iterator as value head
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for (i = 0; i < medianFilter->numNodes - 1; i++) {
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if (sample < it->value) {
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if (i == 0) { // replace value head if new node is the smallest
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medianFilter->valueHead = newNode;
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}
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break;
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}
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it = it->nextValue;
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}
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// insert new node in list
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it->prevValue->nextValue = newNode;
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newNode->prevValue = it->prevValue;
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it->prevValue = newNode;
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newNode->nextValue = it;
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if (medianFilter->bufferCnt < medianFilter->numNodes) {
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medianFilter->bufferCnt++;
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}
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// adjust median node
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if (i >= (medianFilter->numNodes / 2)) {
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medianFilter->medianHead = medianFilter->medianHead->nextValue;
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}
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return medianFilter->medianHead->value;
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}
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/**
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*
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*/
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uint8_t MEDIANFILTER_isFull(sMedianFilter_t *medianFilter) {
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if (medianFilter->bufferCnt < medianFilter->numNodes) {
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return 0;
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} else {
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return 1;
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}
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}
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