Realtime spectrum analyzer. Using FFT, linear prediction, or cepstrum smoothing. Version using MEMS microphone and CODEC, named "F746_RealtimeSpectrumAnalyzer_MEMS_Mic" is registered. リアルタイム スペクトル解析器.解析の手法:FFT,線形予測法,ケプストラムによる平滑化の3種類.このプログラムの説明は,CQ出版社のインターフェース誌,2016年4月号に掲載.外付けのマイクまたは他の信号源等を A0 に接続する.線形予測法,ケプストラムは,スペクトル解析の対象を音声信号に想定してパラメータを設定している.MEMS マイクと CODEC を使ったバージョンを "F746_RealtimeSpectrumAnalyzer_MEMS_Mic" として登録.
Dependencies: BSP_DISCO_F746NG BUTTON_GROUP LCD_DISCO_F746NG TS_DISCO_F746NG UIT_FFT_Real mbed
MyClasses/AnalysisBase.cpp@18:6630d61aeb3c, 2016-02-22 (annotated)
- Committer:
- MikamiUitOpen
- Date:
- Mon Feb 22 13:54:51 2016 +0000
- Revision:
- 18:6630d61aeb3c
- Parent:
- 4:99d4d5ea06a2
19
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
MikamiUitOpen | 0:5c237fdcba23 | 1 | //------------------------------------------------------- |
MikamiUitOpen | 0:5c237fdcba23 | 2 | // Base class for spectrum analysis |
MikamiUitOpen | 0:5c237fdcba23 | 3 | // |
MikamiUitOpen | 4:99d4d5ea06a2 | 4 | // 2015/12/15, Copyright (c) 2015 MIKAMI, Naoki |
MikamiUitOpen | 0:5c237fdcba23 | 5 | //------------------------------------------------------- |
MikamiUitOpen | 0:5c237fdcba23 | 6 | |
MikamiUitOpen | 0:5c237fdcba23 | 7 | #include "AnalysisBase.hpp" |
MikamiUitOpen | 0:5c237fdcba23 | 8 | |
MikamiUitOpen | 0:5c237fdcba23 | 9 | namespace Mikami |
MikamiUitOpen | 0:5c237fdcba23 | 10 | { |
MikamiUitOpen | 3:7c26b701f363 | 11 | AnalyzerBase::AnalyzerBase(int nData, int nFft, int nUse) |
MikamiUitOpen | 3:7c26b701f363 | 12 | : N_DATA_(nData), N_FFT_(nFft), |
MikamiUitOpen | 3:7c26b701f363 | 13 | fft_(nFft), wHm_(nData-1, nUse), |
MikamiUitOpen | 4:99d4d5ea06a2 | 14 | xData_(new float[nUse]), wData_(new float[nUse]) {} |
MikamiUitOpen | 0:5c237fdcba23 | 15 | |
MikamiUitOpen | 0:5c237fdcba23 | 16 | AnalyzerBase::~AnalyzerBase() |
MikamiUitOpen | 0:5c237fdcba23 | 17 | { |
MikamiUitOpen | 0:5c237fdcba23 | 18 | delete[] xData_; |
MikamiUitOpen | 0:5c237fdcba23 | 19 | } |
MikamiUitOpen | 0:5c237fdcba23 | 20 | |
MikamiUitOpen | 0:5c237fdcba23 | 21 | void AnalyzerBase::Execute(const float xn[], float db[]) |
MikamiUitOpen | 0:5c237fdcba23 | 22 | { |
MikamiUitOpen | 0:5c237fdcba23 | 23 | // Differencing |
MikamiUitOpen | 0:5c237fdcba23 | 24 | for (int n=0; n<N_DATA_-1; n++) |
MikamiUitOpen | 0:5c237fdcba23 | 25 | xData_[n] = xn[n+1] - xn[n]; |
MikamiUitOpen | 0:5c237fdcba23 | 26 | |
MikamiUitOpen | 4:99d4d5ea06a2 | 27 | // Windowing (FFT, cepstrum: + zero-padding) |
MikamiUitOpen | 4:99d4d5ea06a2 | 28 | wHm_.Execute(xData_, wData_); |
MikamiUitOpen | 4:99d4d5ea06a2 | 29 | |
MikamiUitOpen | 4:99d4d5ea06a2 | 30 | // Pure virtual function for analyzing |
MikamiUitOpen | 4:99d4d5ea06a2 | 31 | Analyze(wData_, db); |
MikamiUitOpen | 0:5c237fdcba23 | 32 | } |
MikamiUitOpen | 0:5c237fdcba23 | 33 | } |
MikamiUitOpen | 3:7c26b701f363 | 34 |