Files
snapclient/components/libmedian/MedianFilter.c
Karl Osterseher 76a9b9acce - remove bug in i2s driver resulting in overwriting DMA descriptor while initialization leading to wrong initial sync
- change some function return values from int8_t to int32_t
- improve syncing
  o try to mimic original algorithm used by badaix
- latency_buffer_full() call in player sporadically returns negative value
  which led to a unnecessary vTaskDelay --> resolved
- use esp_timer_get_time() instead of gettimeofday() for timestamping
- enable IRAM optimazations for WIFI
- decrease WIFI RX buffers

Signed-off-by: Karl Osterseher <karli_o@gmx.at>
2022-10-21 19:30:51 +02:00

121 lines
3.2 KiB
C

/*
* MedianFilter.c
*
* Created on: May 19, 2018
* Author: alexandru.bogdan
* Editor: Carlos Derseher
*
* original source code:
* https://github.com/accabog/MedianFilter
*/
/**
* This Module expects odd numbers of buffer lengths!!!
*/
#include <stdint.h>
#include "MedianFilter.h"
/**
*
*/
int MEDIANFILTER_Init(sMedianFilter_t *medianFilter) {
if (medianFilter && medianFilter->medianBuffer &&
(medianFilter->numNodes % 2) && (medianFilter->numNodes > 1)) {
// initialize buffer nodes
for (unsigned int i = 0; i < medianFilter->numNodes; i++) {
medianFilter->medianBuffer[i].value = 0;
medianFilter->medianBuffer[i].nextAge =
&medianFilter->medianBuffer[(i + 1) % medianFilter->numNodes];
medianFilter->medianBuffer[i].nextValue =
&medianFilter->medianBuffer[(i + 1) % medianFilter->numNodes];
medianFilter->medianBuffer[(i + 1) % medianFilter->numNodes].prevValue =
&medianFilter->medianBuffer[i];
}
// initialize heads
medianFilter->ageHead = medianFilter->medianBuffer;
medianFilter->valueHead = medianFilter->medianBuffer;
medianFilter->medianHead =
&medianFilter->medianBuffer[medianFilter->numNodes / 2];
medianFilter->bufferCnt = 0;
return 0;
}
return -1;
}
/**
*
*/
int64_t MEDIANFILTER_Insert(sMedianFilter_t *medianFilter, int64_t sample) {
unsigned int i;
sMedianNode_t *newNode, *it;
if (medianFilter->ageHead ==
medianFilter->valueHead) { // if oldest node is also the smallest node,
// increment value head
medianFilter->valueHead = medianFilter->valueHead->nextValue;
}
if ((medianFilter->ageHead == medianFilter->medianHead) ||
(medianFilter->ageHead->value > medianFilter->medianHead->value)) {
// prepare for median correction
medianFilter->medianHead = medianFilter->medianHead->prevValue;
}
// replace age head with new sample
newNode = medianFilter->ageHead;
newNode->value = sample;
// remove age head from list
medianFilter->ageHead->nextValue->prevValue =
medianFilter->ageHead->prevValue;
medianFilter->ageHead->prevValue->nextValue =
medianFilter->ageHead->nextValue;
// increment age head
medianFilter->ageHead = medianFilter->ageHead->nextAge;
// find new node position
it = medianFilter->valueHead; // set iterator as value head
for (i = 0; i < medianFilter->numNodes - 1; i++) {
if (sample < it->value) {
if (i == 0) { // replace value head if new node is the smallest
medianFilter->valueHead = newNode;
}
break;
}
it = it->nextValue;
}
// insert new node in list
it->prevValue->nextValue = newNode;
newNode->prevValue = it->prevValue;
it->prevValue = newNode;
newNode->nextValue = it;
if (medianFilter->bufferCnt < medianFilter->numNodes) {
medianFilter->bufferCnt++;
}
// adjust median node
if (i >= (medianFilter->numNodes / 2)) {
medianFilter->medianHead = medianFilter->medianHead->nextValue;
}
return medianFilter->medianHead->value;
}
/**
*
*/
uint32_t MEDIANFILTER_isFull(sMedianFilter_t *medianFilter) {
if (medianFilter->bufferCnt >= medianFilter->numNodes) {
return 1;
} else {
return 0;
}
}