GainPred.java

package org.mobicents.media.server.impl.dsp.audio.g729;

public class GainPred {

	/*---------------------------------------------------------------------------*
	 * Function  Gain_predict                                                    *
	 * ~~~~~~~~~~~~~~~~~~~~~~                                                    *
	 * MA prediction is performed on the innovation energy (in dB with mean      *
	 * removed).                                                                 *
	 *---------------------------------------------------------------------------*/
	public static void gain_predict(
	   float past_qua_en[], /* (i)     :Past quantized energies        */
	   float code[],        /* (i)     :Innovative vector.             */
	   int l_subfr,         /* (i)     :Subframe length.               */
	   FloatPointer gcode0        /* (o)     :Predicted codebook gain        */
	)
	{
	   float ener_code, pred_code;
	   int i;

	   pred_code = LD8KConstants.MEAN_ENER ;

	   /* innovation energy */
	   ener_code = (float)0.01;
	   for(i=0; i<l_subfr; i++)
	     ener_code += code[i] * code[i];
	   ener_code = (float)10.0 * (float)Math.log10(ener_code /(float)l_subfr);

	   pred_code -= ener_code;

	   /* predicted energy */
	   for (i=0; i<4; i++) pred_code += TabLD8k.pred[i]*past_qua_en[i];

	   /* predicted codebook gain */
	   gcode0.value = pred_code;
	   gcode0.value = (float)Math.pow((double)10.0,(double)(gcode0.value/20.0));   /* predicted gain */

	   return;
	}


	/*---------------------------------------------------------------------------*
	 * Function  gain_update                                                     *
	 * ~~~~~~~~~~~~~~~~~~~~~~                                                    *
	 * update table of past quantized energies                                   *
	 *---------------------------------------------------------------------------*/
	public static void gain_update(
	   float past_qua_en[],   /* input/output :Past quantized energies     */
	   float g_code           /*  input: gbk1[indice1][1]+gbk2[indice2][1] */
	)
	{
	   int i;

	   /* update table of past quantized energies */
	   for (i = 3; i > 0; i--)
	     past_qua_en[i] = past_qua_en[i-1];
	   past_qua_en[0] = (float)20.0*(float)Math.log10((double)g_code);

	   return;
	}

	/*---------------------------------------------------------------------------*
	 * Function  gain_update_erasure                                             *
	 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                             *
	 * update table of past quantized energies (frame erasure)                   *
	 *---------------------------------------------------------------------------*
	 *     av_pred_en = 0.0;                                                     *
	 *     for (i = 0; i < 4; i++)                                               *
	 *        av_pred_en += past_qua_en[i];                                      *
	 *     av_pred_en = av_pred_en*0.25 - 4.0;                                   *
	 *     if (av_pred_en < -14.0) av_pred_en = -14.0;                           *
	 *---------------------------------------------------------------------------*/
	public static void gain_update_erasure(
	   float past_qua_en[]     /* input/output:Past quantized energies        */
	)
	{
	   int i;
	   float  av_pred_en;

	    av_pred_en = (float)0.0;
	    for (i = 0; i < 4; i++)
	        av_pred_en += past_qua_en[i];
	    av_pred_en = av_pred_en*(float)0.25 - (float)4.0;
	    if (av_pred_en < (float)-14.0) av_pred_en = (float)-14.0;

	    for (i = 3; i > 0; i--)
	        past_qua_en[i] = past_qua_en[i-1];
	    past_qua_en[0] = av_pred_en;

	    return;
	}


}