/************************************************************************ * *  quant.c, part of tmn (TMN encoder) * *  Copyright (C) 1997  University of BC, Canada * *  Contacts:  *  Michael Gallant                   <mikeg@ee.ubc.ca> *  Guy Cote                          <guyc@ee.ubc.ca> *  Berna Erol                        <bernae@ee.ubc.ca> * *  UBC Image Processing Laboratory   http://www.ee.ubc.ca/image *  2356 Main Mall                    tel.: +1 604 822 4051 *  Vancouver BC Canada V6T1Z4        fax.: +1 604 822 5949 * *  Copyright (C) 1995, 1996  Telenor R&D, Norway * *  Contacts: *  Robert Danielsen                  <Robert.Danielsen@nta.no> * *  Telenor Research and Development  http://www.nta.no/brukere/DVC/ *  P.O.Box 83                        tel.:   +47 63 84 84 00 *  N-2007 Kjeller, Norway            fax.:   +47 63 81 00 76 * ************************************************************************//* Disclaimer of Warranty *  * These software programs are available to the user without any license fee * or royalty on an "as is" basis. The University of British Columbia * disclaims any and all warranties, whether express, implied, or * statuary, including any implied warranties or merchantability or of * fitness for a particular purpose.  In no event shall the * copyright-holder be liable for any incidental, punitive, or * consequential damages of any kind whatsoever arising from the use of * these programs. *  * This disclaimer of warranty extends to the user of these programs and * user's customers, employees, agents, transferees, successors, and * assigns. *  * The University of British Columbia does not represent or warrant that the * programs furnished hereunder are free of infringement of any * third-party patents. *  * Commercial implementations of H.263, including shareware, are subject to * royalty fees to patent holders.  Many of these patents are general * enough such that they are unavoidable regardless of implementation * design. *  */#include"sim.h"static int MQ_chroma_QP_table[32] = {0,1,2,3,4,5,6,6,7,8,9,9,10,10,11,11,12,12,12,13,13,13,14,14,14,14,14,15,15,15,15,15};/********************************************************************** * *	Name:        Quant_blk *	Description:	quantizer * *	Input:        pointers to coeff and qcoeff * *	Returns: *	Side effects: * *	Date: 940111	Author:	<klillevo@mailbox.jf.intel.com> * ***********************************************************************/void Quant_blk (int *coeff, int *qcoeff, int QP, int Mode, int block){  int i;  int level;    /*Modify the chroma quantizer if modified quantization mode is in use*/  if (modified_quantization && (block == 4 || block == 5))   {    QP=MQ_chroma_QP_table[QP];                     }  if (QP)  {    if (Mode == MODE_INTRA || Mode == MODE_INTRA_Q)    {                           /* Intra */      /* advanced intra coding quantization */      if (advanced_intra_coding)      {        for (i = 0; i < 64; i++)        {           if (!modified_quantization || QP >= 8)          {            /* clipping to [-127,+127] */            qcoeff[block*64 + i] = mmin (127, mmax (-127, (coeff[block*64 + i] + sign(coeff[block*64 + i]) * QP/2) / (2 * QP)));          } else          {            /* no clipping, quantized coefficients  */             qcoeff[block*64 + i] = (coeff[block*64 + i] + sign(coeff[block*64 + i]) * QP/2) / (2 * QP);          }        }      } else      {        qcoeff[block*64] = mmax (1, mmin (254, (coeff[block*64]+4) / 8));        for (i = 1; i < 64; i++)        {          level = (abs (coeff[block*64 + i])) / (2 * QP);          /* if QP is larger than 8, don't use extended quantization */          if (!modified_quantization || QP >= 8)          {            /* clipping to [-127,+127] */            qcoeff[block*64 + i] = mmin (127, mmax (-127, sign (coeff[block*64 + i]) * level));          } else          {            /* no clipping, quantized coefficients  */            qcoeff[block*64 + i] = sign (coeff[block*64 + i]) * level;          }        }      }    }          else    {                           /* non Intra */      for (i = 0; i < 64; i++)      {        level = (abs (coeff[block*64 + i]) - QP / 2) / (2 * QP);        /* if QP is larger than 8, don't use extended quantization */        if (!modified_quantization || QP >= 8)        {          /* clipping to [-127,+127] */          qcoeff[block*64 + i] = mmin (127, mmax (-127, sign (coeff[block*64 + i]) * level));        } else        {          /* no clipping, quantized coefficients  */          qcoeff[block*64 + i] = sign (coeff[block*64 + i]) * level;        }      }    }  }      else  {    /* No quantizing. Used only for testing. Bitstream will not be     * decodable whether clipping is performed or not */    for (i = 0; i < 64; i++)    {      qcoeff[block*64 + i] = coeff[block*64 + i];    }  }    return;}/********************************************************************** * *	Name:        Dequant *	Description:	dequantizer * *	Input:        pointers to coeff and qcoeff * *	Returns: *	Side effects: * *	Date: 940111	Author:	Karl.Lillevold@nta.no * ***********************************************************************/void Dequant (int *qcoeff,int *rcoeff, int QP, int Mode, int block){  int i;  /* Modify the chorama quantizer if modified quantization mode is in use */  if (modified_quantization && (block == 4 || block == 5))  {    QP=MQ_chroma_QP_table[QP];  }  if (QP)  {    for (i = 0; i < 64; i++)    {      if (qcoeff[block * 64 + i])      {        if ((advanced_intra_coding) && (Mode == MODE_INTRA || Mode == MODE_INTRA_Q))        {          /* Advanced intra coding dequantization */          rcoeff[block * 64 + i] = (QP * (2 * qcoeff[block * 64 + i]));        } else        {          if ((QP % 2) == 1)            rcoeff[block * 64 + i] = QP * (2 * abs (qcoeff[block * 64 + i]) + 1);          else            rcoeff[block * 64 + i] = QP * (2 * abs (qcoeff[block * 64 + i]) + 1) - 1;          rcoeff[block * 64 + i] = sign (qcoeff[block * 64 + i]) * rcoeff[block * 64 + i];        }      } else        rcoeff[block * 64 + i] = 0;    }    if ((Mode == MODE_INTRA || Mode == MODE_INTRA_Q) && !advanced_intra_coding)    {      /* Intra (except when advanced intra coding is used) */      rcoeff[block * 64] = qcoeff[block * 64] * 8;    }  } else  {    /* No quantizing at all */    for (i = 0; i < 64; i++)    {      rcoeff[block * 64 + i] = qcoeff[block * 64 + i];    }  }  return;}int Get_restricted_MQ(int dquant,int QP_prev){  int new_dquant;  new_dquant=dquant;  /*recalculate dquant*/  if (QP_prev == 31)  {    if (dquant <= -5)      new_dquant=-5;    else      new_dquant=-3;  }  else  if (QP_prev == 30)  {    if (dquant <= 0)      new_dquant=-3;    else      new_dquant=1;  }  else  if (QP_prev == 29)  {    if (dquant <= 0)      new_dquant=-3;    else      new_dquant=2;  }  else  if (QP_prev >= 21)  {    if (dquant <= 0)      new_dquant=-3;     else      new_dquant=3;   }   else   if (QP_prev >= 11)   {     if (dquant <= 0)       new_dquant=-2;     else       new_dquant=2;   }   else   if (QP_prev >= 2)   {     if (dquant <= 0)       new_dquant=-1;     else       new_dquant=1;   }   else   {     if (dquant <= 1)       new_dquant=1;     else       new_dquant=2;   }   return new_dquant;}