#ifndef EMG_UTIL_H
#define EMG_UTIL_H

// SOS 绯绘暟锛�20-450 Hz 甯﹂�氾紝fs=1000Hz锛�
// const double sos[2][6] = {
//     {1.0000000000, -2.0000000000, 1.0000000000, 1.0, -1.8794729180, 0.8944729180},
//     {1.0000000000, -2.0000000000, 1.0000000000, 1.0, -1.9657267688, 0.9676167688}
// };
// 宸寸壒娌冩柉婊ゆ尝鍣ㄥ弬鏁癝OS 绯绘暟锛�20-450 Hz 甯﹂�氾紝fs=1000Hz锛�
const double sos[2][6] = {
    {1.0000000000,  2.0000000000, 1.0000000000, 1.0,  1.5597000000, 0.6416000000},
    {1.0000000000, -2.0000000000, 1.0000000000, 1.0, -1.8225000000, 0.8373000000}
};
// 鐢� MATLAB 鐢熸垚骞跺浐鍖栧埌 C 鐨勭郴鏁帮紙50Hz 闄锋尝锛宖s=1000Hz锛夐櫡娉㈡护娉⒙峰弬鏁�
// const double NOTCH_B[3] = { 0.961538461538462, -1.846153846153846,  0.961538461538462 };
// const double NOTCH_A[3] = { 1.000000000000000, -1.846153846153846,  0.876923076923077 };
const double NOTCH_B[3] = {0.9955, -1.8936, 0.9955};
const double NOTCH_A[3] = {1.0000, -1.8936, 0.9911};

typedef struct {
    double b[3];   // 鍒嗗瓙绯绘暟: b0, b1, b2
    double a[3];   // 鍒嗘瘝绯绘暟: a0, a1, a2 (a0 閫氬父褰掍竴鍖栦负 1)
    double x1, x2; // 杈撳叆寤惰繜鍗曞厓: x[n-1], x[n-2]
    double y1, y2; // 杈撳嚭寤惰繜鍗曞厓: y[n-1], y[n-2]
} NotchFilter;

    float f0 = 50.0f;//宸ラ
    float q = 30.0f;//璐ㄩ噺绯绘暟
    float low_cut = 20.0f;    // 浣庢埅姝㈤鐜�
    float high_cut = 450.0f;  // 楂樻埅姝㈤鐜�
    int order = 4;            // 婊ゆ尝鍣ㄩ樁鏁�
// 宸寸壒娌冩柉婊ゆ尝鍣ㄧ粨鏋勪綋锛坉ouble绫诲瀷锛�
typedef struct {
    double x1, x2;
    double y1, y2;
} BiquadState;

// Symlet 4 (sym4) 婊ゆ尝鍣ㄧ郴鏁帮紙鏍囧噯鍖栵級
static  double sym4_h[8] = {
     0.0266700579010166,
     0.0607514995432352,
    -0.0656160944756398,
    -0.1498879107562273,
     0.4829629131445341,
     0.8365163037378608,
     0.2242848007341553,
    -0.1077300958383618
};

static  double sym4_g[8] = {
    -0.1077300958383618,
    -0.2242848007341553,
     0.8365163037378608,
    -0.4829629131445341,
    -0.1498879107562273,
     0.0656160944756398,
     0.0607514995432352,
    -0.0266700579010166
};



void emg_denoised(double *emg_raw, int length, int fs, double *emg_denoised);
#endif // EMG_UTIL_H