语音信号的fir滤波 ccs

要在CCS中实现语音信号的FIR滤波，可以按照以下步骤进行：

1. 创建一个新的CCS工程，并将其配置为使用你所使用的处理器。

2. 在工程中添加一个新的源文件，将其命名为“fir.c”。

3. 在“fir.c”文件中，编写FIR滤波器的代码。可以使用DSP库函数来简化代码编写。下面是一个示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <math.h>
#include "DSP2833x_Device.h"
#include "DSP2833x_Examples.h"
#include "DSP2833x_GlobalPrototypes.h"
#include "DSP2833x_CpuTimers.h"
#include "DSP2833x_Xintf.h"
#include "DSP2833x_SysCtrl.h"
#include "DSP2833x_Dma.h"
#include "DSP2833x_EPwm_defines.h"
#include "DSP2833x_EPwm.h"
#include "DSP2833x_Gpio.h"
#include "DSP2833x_I2c_defines.h"
#include "DSP2833x_I2c.h"
#include "DSP2833x_McBSP_defines.h"
#include "DSP2833x_McBSP.h"
#include "DSP2833x_PieCtrl.h"
#include "DSP2833x_PieVect.h"
#include "DSP2833x_Spi_defines.h"
#include "DSP2833x_Spi.h"
#include "DSP2833x_XIntrupt.h"
#include "DSP2833x_I2S_defines.h"
#include "DSP2833x_I2S.h"
#include "DSP2833x_ECan_defines.h"
#include "DSP2833x_ECan.h"
#include "DSP2833x_DefaultIsr.h"
#include "fir.h"

#define FIR_FILTER_TAP_NUM   32

int16_t fir_filter_taps[FIR_FILTER_TAP_NUM] = {
    126, 201, 377, 501, 573, 548, 404, 171, -169, -580, -944, -1194,
    -1242, -1059, -649, -57, 651, 1345, 2028, 2577, 2880, 2833, 2372,
    1478, 166, -1468, -3245, -5119, -6900, -8391, -9405, -9804, -9405,
    -8124, -5975, -3083, 351, 4347, 8536, 12920, 17140, 20945, 24138,
    26523, 27918, 28277, 27593, 25908, 23397, 20269, 16763, 13118, 9550,
    6072, 3075, 770, -867, -1815, -2109, -1726, -659, 1039, 3152,
    5018, 6248, 6543, 5757, 3945, 1281, -2059, -5287, -8117, -10298,
    -11332, -11168, -9814, -7688, -4606, -673, 3709, 8230, 12366, 15724,
    18084, 19236, 19078, 17543, 14692, 10720, 5867, 684, -4633, -9571,
    -13665, -16650, -18171, -17929, -15764, -11824, -6529, -707, 5364, 11222,
    16041, 19231, 20454, 19496, 16355, 11120, 4136, -3658, -11742, -19317, -25616,
    -29960, -31931, -31212, -27620, -21223, -12364, -1774, 10268, 22532, 34025, 43035,
    48114, 48114, 43035, 34025, 22532, 10268, -1774, -12364, -21223, -27620, -31212,
    -31931, -29960, -25616, -19317, -11742, -3658, 4136, 11120, 16355, 19496, 20454,
    19231, 16041, 11222, 5364, -707, -6529, -11824, -15764, -17929, -18171, -16650,
    -13665, -9571, -4633, 684, 5867, 10720, 14692, 17543, 19078, 19236, 18084,
    15724, 12366, 8230, 3709, -673, -4606, -7688, -9814, -11168, -11332, -10298,
    -8117, -5287, -2059, 1281, 3945, 5757, 6543, 6248, 5018, 3152, 1039,
    -659, -1726, -2109, -1815, -867, 770, 3075, 6072, 9550, 13118, 16763,
    20269, 23397, 25908, 27593, 28277, 27918, 26523, 24138, 20945, 17140, 12920,
    8536, 4347, 351, -3083, -5975, -8124, -9405, -9804, -9405, -8391, -6900,
    -5119, -3245, -1468, 166, 1478, 2372, 2833, 2880, 2577, 2028, 1345, 651,
    -57, -649, -1059, -1242, -1194, -944, -580, -169, 171, 404, 548, 573,
    501, 377, 201, 126
};

int16_t fir_filter_buffer[FIR_FILTER_TAP_NUM] = { 0 };

void fir_filter(int16_t *input, int16_t *output, uint16_t length)
{
    uint16_t i, j;
    int32_t acc;

    for (i = 0; i < length; i++) {
        fir_filter_buffer[0] = input[i];
        acc = 0;

        for (j = 0; j < FIR_FILTER_TAP_NUM; j++) {
            acc += fir_filter_taps[j] * fir_filter_buffer[j];
        }

        for (j = FIR_FILTER_TAP_NUM - 1; j > 0; j--) {
            fir_filter_buffer[j] = fir_filter_buffer[j - 1];
        }

        output[i] = (int16_t)(acc >> 15);
    }
}

4. 在“fir.h”文件中，定义FIR滤波器的函数原型和所需的常量和变量。下面是一个示例代码：

#ifndef FIR_H_
#define FIR_H_

extern void fir_filter(int16_t *input, int16_t *output, uint16_t length);

#endif /* FIR_H_ */

5. 在主函数中，调用FIR滤波器函数来对语音信号进行滤波。下面是一个示例代码：

#include "DSP2833x_Device.h"
#include "DSP2833x_Examples.h"
#include "DSP2833x_GlobalPrototypes.h"
#include "DSP2833x_CpuTimers.h"
#include "DSP2833x_Xintf.h"
#include "DSP2833x_SysCtrl.h"
#include "DSP2833x_Dma.h"
#include "DSP2833x_EPwm_defines.h"
#include "DSP2833x_EPwm.h"
#include "DSP2833x_Gpio.h"
#include "DSP2833x_I2c_defines.h"
#include "DSP2833x_I2c.h"
#include "DSP2833x_McBSP_defines.h"
#include "DSP2833x_McBSP.h"
#include "DSP2833x_PieCtrl.h"
#include "DSP2833x_PieVect.h"
#include "DSP2833x_Spi_defines.h"
#include "DSP2833x_Spi.h"
#include "DSP2833x_XIntrupt.h"
#include "DSP2833x_I2S_defines.h"
#include "DSP2833x_I2S.h"
#include "DSP2833x_ECan_defines.h"
#include "DSP2833x_ECan.h"
#include "DSP2833x_DefaultIsr.h"
#include "fir.h"

#define SAMPLE_BUFFER_SIZE  256

int16_t sample_buffer[SAMPLE_BUFFER_SIZE];
int16_t filtered_buffer[SAMPLE_BUFFER_SIZE];

void main(void)
{
    uint16_t i;

    // 初始化系统时钟和GPIO
    InitSysCtrl();
    InitGpio();

    // 初始化McBSP
    InitMcbspa();

    // 读取语音信号到采样缓冲区
    McbspaRcvAll(sample_buffer, SAMPLE_BUFFER_SIZE * 2, 0);

    // 对采样缓冲区进行FIR滤波
    fir_filter(sample_buffer, filtered_buffer, SAMPLE_BUFFER_SIZE);

    // 将滤波后的语音信号发送回McBSP
    McbspaXmtAll(filtered_buffer, SAMPLE_BUFFER_SIZE * 2);

    // 死循环
    while (1);
}

以上是一个基本的实现语音信号的FIR滤波的CCS工程。要注意的是，具体实现方式可能会因为处理器类型和需要滤波的语音信号的特性而略有不同。