amf_tonecontrolbass.c

ADI SHARC DSP 音频算法标准模块库

// Copyright(c) 2005 Analog Devices, Inc. All Rights Reserved.
// This software is proprietary and confidential to Analog Devices, Inc. and its licensors.

// File    : $Id: //depot/development/visualaudio/modules/2.5.0/SHARC/Source/AMF_ToneControlBass.c#3 $ 
// Part of : VisualAudio V2.5.0 
// Updated : $Date: 2006/10/12 $ by $Author: Fernando $



#include "AMF_ToneControlBass.h"
#include "VA_GeneralHelperFunctions.h"
                        
void AMF_ToneControlBass_Render(AMF_ToneControlBass * restrict instance,float * restrict * buffers, int tickSize);


// NOTE: The C version of this function is for reference only (it is
//       intended just to show the general algorithm that the module
//       uses), and it may not have been fully tested
#if 0    // C example code

#pragma optimize_for_speed
SEG_MOD_FAST_CODE  void AMF_ToneControlBass_Render(AMF_ToneControlBass * restrict instance,float * restrict * buffers,int tickSize) {
    int i;
    float amp = instance->amp;
    float amp2;
    float ampTarget = instance->ampTarget;
    float state = instance->state;
    float ampSmoothing = instance->ampSmoothing;
    float b0 = instance->b0;
    float oneMinusRate = 1.0 - ampSmoothing;
    float tmp;
    float allPass;
    float *in = buffers[0]; // Don't use restrict because we say they can alias (see .h file)
    float *out = buffers[1];
    float *t=out;

    // These coefs are used in a modified version of the smoothing calculation
    //   which computes two samples at a time, and is thus good for SIMD
    float c1 = oneMinusRate * oneMinusRate;
    float c2 = 1 - c1;
        
    // compute the allpass into a temp buffer (the output in this case)
    for (i=0; i<tickSize; i++) {
        tmp =  in[i] - b0 * state;
        allPass = b0 * tmp + state;
        state = tmp;
        t[i] = allPass;
    }
    instance->state = state;

    amp2 = amp * oneMinusRate + ampTarget * ampSmoothing;

    // the Regalia-Mitra low shelf with smoothed Amp
    
    // This loop is layed out as what gets done in the SIMD optimization in the asm version
    for (i=0; i<tickSize; i+=2) {
        amp = c1*amp + c2*ampTarget;
        amp2 = c1*amp2 + c2*ampTarget;
        out[i] = 0.5 * ( amp * (in[i] + t[i]) + (in[i] - t[i]) );
        out[i+1] = 0.5 * ( amp2 * (in[i+1] + t[i+1]) + (in[i+1] - t[i+1]) );
    }
    instance->amp = amp;
}
#endif


SEG_MOD_SLOW_CONST const AMF_ModuleClass AMFClassToneControlBass = {

    /* Flags */
    0,

    /** Reference to render function. */
    (AMF_RenderFunction)AMF_ToneControlBass_Render, 

    /* Default bypass */
    (void *)0,

    /* Input descriptor - 1 input, and it is mono. */
    1, 0,

    /* Output descriptor - 1 output, and it is mono. */
    1, 0,
};