temp.c

高通的cmda语音压缩算法is96a源代码. 针对自己的dsp将最耗时的c改成汇编就几乎是商用代码了.

agc(input, output, return_vals, length, factor) 
float *input, *output, *return_vals;
INTTYPE   length;
float *factor;
{
    INTTYPE i;
    float input_energy, output_energy;
    float norm;

    input_energy=0;
    output_energy=0;
    for (i=0; i<length; i++) {
	input_energy+=input[i]*input[i];
	output_energy+=output[i]*output[i];
    }
    if (output_energy>.1) {
	norm=sqrt((double)(input_energy/output_energy));
    }
    else {
	norm= *factor;
    }
    *factor=AGC_FACTOR*(*factor)+(1-AGC_FACTOR)*norm;

    for (i=0; i<length; i++) {
	return_vals[i]=output[i]*(*factor);
    }
}