amf_testgensine.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_TestGenSine.c#3 $ 
// Part of : VisualAudio V2.5.0 
// Updated : $Date: 2006/10/12 $ by $Author: Fernando $



#include "AMF_TestGenSine.h"
#include <math.h>

void AMF_TestGenSine_Render(AMF_TestGenSine * restrict instance,float * restrict * buffers,int tickSize);

SEG_MOD_FAST_CODE  void AMF_TestGenSine_Render(AMF_TestGenSine * restrict instance,float * restrict * buffers,int tickSize) {
    int i;
    float *out = buffers[0];
    float phaseinc, phase;

    phase = instance->phase;
    phaseinc = instance->phaseInc;
    
    for (i=0; i<tickSize; i++) {
        phase += phaseinc;
        if (phase > (2*3.141592653589793)) phase -= (2*3.141592653589793);
        if (phase < 0) phase += (2*3.141592653589793);
        out[i]=sinf(phase);
    }
    // In a module intended for speed, we might pull the wraparound out
    // here after the main loop (they would have to be turned into while loops,
    // probably), but since a high frequency might make for a "large" phase
    // later on in the tick, that could cause slight errors in the 
    // (phase = "large value" + phaseInc) calculation (due to how floating-
    // point addition works). So, since this is a module intended more for
    // accuracy than speed, we'll put the wraparound inside the loop.
    instance->phase = phase;
}

SEG_MOD_SLOW_CONST const AMF_ModuleClass AMFClassTestGenSine = {
    
    /* Flags */
    0,
     
    /* Render function */
    (AMF_RenderFunction)AMF_TestGenSine_Render,

    /* Default bypass */
    (void *)0,
    
    /* Input descriptor - no inputs. */
    0, 0,

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