fir_h.h

音频信号降采样程序 支持48k->8k 24k->8k 8k->1k 的降采样.实现方法,先做低通滤波,再做采样点抽取.低通滤波起使用67点FIR,系数由matlab使用窗函数法生成

double h_1[H1_Length]={0.000771660330143	,-0,	-0.000906801196153,	0,	0.001239770366743,	-0,	
			-0.001804031594338,	-0,	0.002636654274513,	-0,	-0.00378060556787,	0,	
			0.005288629238368	,-0,	-0.007229837609052,	0,	0.009701192541325,	-0	,
			-0.012848362648456,	0	,0.016905958690854,	-0,	-0.022281692032865,	0,	
			0.029752635061766,	-0,	-0.040997605036481,	0,	0.060406577873616,	-0	,
			-0.104126248060974,	0,	0.31764687355101,	0.5,	0.31764687355101,	0,	
			-0.104126248060974,	-0,	0.060406577873616,	0,	-0.040997605036481,	-0,	
			0.029752635061766,	0,	-0.022281692032865,	-0,	0.016905958690854,	0,	
			-0.012848362648456,	-0,	0.009701192541325,	0,	-0.007229837609052,	-0,	
			0.005288629238368,	0,	-0.00378060556787,	-0,	0.002636654274513,	-0,	
			-0.001804031594338,	-0,	0.001239770366743,	0,	-0.000906801196153,	-0,	
			0.000771660330143},//FIR_Window_fun_mathods.m wp=0.45*pi;ws=0.55*pi;
		h_2[H2_Length]={-0.000130690704099,	0.000610855735806,	0.000841945990458,	0.000207583486759	,-0.000893731086409	,-0.001384001851206	,
			-0.000407794700598,	0.001514755751498,	0.002450151988018,	0.000803399008948,	-0.002525062668079	,
			-0.004179165490996,	-0.001487969475309,	0.003987176449371,	0.006756302278544,	0.00259073018814,	
			-0.005997089373387,	-0.010467226002265,	-0.004310391622461,	0.008734170562754,	0.015827654541776,	
			0.007001965997077,	-0.012587919337573,	-0.023938197002412,	-0.011433388375098,	0.018549191728103,	
			0.037691669260019,	0.019759289432364,	-0.029872954997547,	-0.067805570478891,	-0.041511152436098,	
			0.06568939540691,	0.211216339281132,	0.315259312157935,	0.315259312157935,	0.211216339281132,	
			0.06568939540691,	-0.041511152436098,	-0.067805570478891,	-0.029872954997547,	0.019759289432364,	
			0.037691669260019,	0.018549191728103,	-0.011433388375098,	-0.023938197002412,	-0.012587919337573,	
			0.007001965997077,	0.015827654541776,	0.008734170562754,	-0.004310391622461,	-0.010467226002265,	
			-0.005997089373387,	0.00259073018814,	0.006756302278544,	0.003987176449371,	-0.001487969475309,	
			-0.004179165490996,	-0.002525062668079,	0.000803399008948,	0.002450151988018,	0.001514755751498,	
			-0.000407794700598,	-0.001384001851206,	-0.000893731086409,	0.000207583486759,	0.000841945990458,	
			0.000610855735806,	-0.000130690704099};