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标题:
实时fir滤波器的输出长度是否和输入长度一样长？
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作者:
freebigfish
时间:
2019-11-8 17:20
标题:
实时fir滤波器的输出长度是否和输入长度一样长？
各位大神，我有一个疑问。fir的输出序列长度按道理是输入序列的长度+滤波器的阶数。可最近看了一个代码，它的输出序列长度冒似与输入序列长度相同，恳请指点一下。
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滤波函数：
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#define NUM_TAPS 48
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#define NUM_DATA 80
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void floatPointFir(float *x, float *h, short order, float *y, float *w)
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{
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short i;
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float sum;
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w[0] = *x++; // Get the current data to delay line
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for (sum=0, i=0; i<order; i++) // FIR filter processing
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{
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sum += h
* w
;
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}
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*y++ = sum; // Save filter output
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for (i=order-1; i>0; i--) // Update data delay line
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{
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w
= w[i-1] ;
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}
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}
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测试代码：
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float w[NUM_TAPS];
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void main()
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{
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FILE *fpIn,*fpOut;
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short i;
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char temp[2];
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float x, // Input data
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y; // Output data
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fpIn = fopen("..\\data\\input.pcm", "rb");
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fpOut = fopen("..\\data\\output.pcm", "wb");
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if (fpIn == NULL)
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{
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printf("Can't open input file\n");
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exit(0);
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}
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// Initialize for filtering process
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for (i=0; i<NUM_TAPS; i++)
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{
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w
= 0.0;
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}
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// Begin filtering the data
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while (fread(&temp, sizeof(char), 2, fpIn) == 2)
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{
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x = (float)((temp[1]<<8)|(temp[0]&0xff));
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// Filter the data x and save output y
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floatPointFir(&x, firCoefFloatingPoint, NUM_TAPS, &y, w);
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temp[0] = (char)((short)y&0xff);
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temp[1] = (char)(((short)y>>8)&0xff);
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fwrite(&temp, sizeof(char), 2, fpOut);
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}
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fclose(fpIn);
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fclose(fpOut);
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}
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作者:
helendcany
时间:
2019-11-21 13:38
路过。
作者:
freebigfish
时间:
2019-11-25 09:10
怎么看不到回复啊
作者:
freebigfish
时间:
2019-12-4 09:03
大神们都忙，不屑一顾
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