rate.c

linux下将各类格式图片转换工具

        VBV_buffer -= frameBits;

    VBV_buffer += bufferFillRate;
    if (VBV_buffer < 0 && wantVbvUnderflowWarning)
        pm_message("WARNING - VBV buffer underflow (%d)", VBV_buffer);
    if (VBV_buffer > buffer_size && wantVbvOverflowWarning)
        pm_message("WARNING - VBV buffer overflow (%d > %d)",
                   VBV_buffer, buffer_size);
}



/*===========================================================================*
 *
 * updateRateControl
 *
 *      Update the statistics kept, after end of frame.  Resets
 *  various global variables
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   many global variables
 *
 *===========================================================================*/
void
updateRateControl(int const type) {
    int totalBits, frameComplexity, pctAllocUsed, pctGOPUsed;
    float avgQuant;
    const char *strPtr;

    totalBits = rc_totalFrameBits;
    avgQuant = ((float) rc_totalQuant / (float) rc_numBlocks);
    frameComplexity = totalBits * avgQuant;
    pctAllocUsed = (totalBits *100 / current_Tx);
    rc_R -= totalBits;
    pctGOPUsed = (rc_R *100/ rc_G);
  
    avg_act = (total_act_j / MB_cnt);
  
    updateVBVBuffer(totalBits);
  
    switch (type) {
    case TYPE_IFRAME:
        Ti = current_Tx;
        d0_i = currentVirtBuf;
        Ni--;
        Si = totalBits;
        Qi = avgQuant;
        Xi = frameComplexity;
        break;
    case TYPE_PFRAME:
        Tp = current_Tx;
        d0_p = currentVirtBuf;
        Np--;
        Sp = totalBits;
        Qp = avgQuant;
        Xp = frameComplexity;
        break;
    case TYPE_BFRAME:
        Tb = current_Tx;
        d0_b = currentVirtBuf;
        Nb--;
        Sb = totalBits;
        Qb = avgQuant;
        Xb = frameComplexity;
        break;
    }
  
  
    /*  Print Frame info */
    strPtr = Frame_trailer1;
    DBG_PRINT(("%s\n",strPtr));
    strPtr = Frame_trailer2;
    DBG_PRINT(("%s\n",strPtr));
    strPtr = Frame_trailer3;
    DBG_PRINT(("%s\n",strPtr));
  
    sprintf(rc_buffer, "%6d  %2.2f  %6d  %3d  %2.2f %7d   "
            "%3d %7d   %3d  %6d %6d",
            totalBits, avgQuant, frameComplexity, avg_act, N_act, 
            currentVirtBuf, pctAllocUsed, rc_R, pctGOPUsed, 
            VBV_buffer, VBV_remainingDelay);
#ifdef RC_STATS_FILE
    fprintf(RC_FILE,"%s\n", rc_buffer);
    fflush(RC_FILE);
#endif
    DBG_PRINT(("%s\n",rc_buffer));
  
    Nx--;
    rc_totalMBBits= rc_bitsThisMB= rc_totalFrameBits=rc_totalOverheadBits = 0;
    rc_numBlocks = rc_totalQuant = total_act_j = currentVirtBuf = 0;
  
    DBG_PRINT(("GOP now has %d bits remaining (%3d%%) for %d frames .. , "
               "Ni= %d, Np= %d, Nb= %d\n", 
               rc_R, (rc_R*100/rc_G), (Ni+Np+Nb), Ni, Np, Nb));
  
}


/*===========================================================================*
 *
 * MB_RateOut
 *
 *      Prints out sampling of MB rate control data.  Every "nth" block
 *	stats are printed, with "n" controled by global RC_MB_SAMPLE_RATE
 *	(NB. "skipped" blocks do not go through this function and thus do not
 *		show up in the sample )
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   none
 *
 * NOTES:
 *
 *===========================================================================*/
void
  MB_RateOut(type)
int type;
{
  int totalBits;
  int pctUsed, pctDone;
  int bitsThisMB;
  int bitsPerMB;
  
  bitsThisMB = rc_bitsThisMB;
  totalBits = rc_totalFrameBits;
  bitsPerMB = (totalBits / rc_numBlocks); 
  pctDone = (rc_numBlocks * 100/ MB_cnt); 
  pctUsed = (totalBits *100/current_Tx);
  
  sprintf(rc_buffer, "%3d  %5d %2d %3d %6d  %3d %6d   %2.2f   %6d %4d    %3d   %3d\n",
	  (rc_numBlocks - 1), bitsThisMB, Qscale, mquant, currentVirtBuf, 
	  rc_Q, act_j, N_act, totalBits, bitsPerMB, pctUsed, pctDone);
#ifdef RC_STATS_FILE
  fprintf(RC_FILE, "%s", rc_buffer);
  fflush(RC_FILE);
#endif
  
  if ( (RC_MB_SAMPLE_RATE) && ((rc_numBlocks -1) % RC_MB_SAMPLE_RATE)) {
    DBG_PRINT(("%s\n", rc_buffer));
  } else {
    return;
  }
}



/*===========================================================================*
 *
 * incNumBlocks()
 *
 *
 * RETURNS:   nothing
 *
 * SIDE EFFECTS:  rc_numBlocks
 *
 * NOTES:
 *
 *===========================================================================*/
void incNumBlocks(num)
     int num;
{
  rc_numBlocks += num;
}


/*===========================================================================*
 *
 * incMacroBlockBits()
 *
 *	Increments the number of Macro Block bits and the total of Frame
 *  bits by the number passed.
 *
 * RETURNS:   nothing
 *
 * SIDE EFFECTS:  rc_totalMBBits
 *
 * NOTES:
 *
 *===========================================================================*/
void incMacroBlockBits(num)
     int num;
{
  rc_bitsThisMB = num;
  rc_totalMBBits += num;
  rc_totalFrameBits += num;
}


/*===========================================================================*
 *
 *   	needQScaleChange(current Q scale, 4 luminance blocks)
 *
 *
 * RETURNS:     new Qscale
 *
 * SIDE EFFECTS:   
 *
 *===========================================================================*/
int needQScaleChange(oldQScale, blk0, blk1, blk2, blk3)
     int oldQScale;
     Block blk0;
     Block blk1;
     Block blk2;
     Block blk3;
{
  
  /*   One more MacroBlock seen */
  rc_numBlocks++;		/* this notes each block num in MB */
  
  checkBufferFullness(oldQScale);
  
  checkSpatialActivity(blk0, blk1, blk2, blk3);
  
  mquant = rc_Q * N_act;
  Qscale = (mquant > 31 ? 31 : mquant);
  Qscale = (Qscale < 1 ? 1 : Qscale);
  rc_totalQuant += Qscale;
  
  if (oldQScale == Qscale)
    return -1;
  else
    return Qscale;
}


/*===========================================================================*
 *
 * determineMBCount() 
 *
 *      Determines number of Macro Blocks in frame from the frame sizes
 *	passed.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   sets the count passed
 *
 *===========================================================================*/
int
  determineMBCount ()
{
  int y,x;
  
  x = (Fsize_x +15)/16;
  y = (Fsize_y +15)/16;
  return  (x * y);
}



/*===========================================================================*
 *
 * void checkBufferFullness ()
 *
 *      Calculates the fullness of the virtual buffer for each
 *  frame type.  Called before encoding each macro block.  Along
 *  with the normalisec spatial activity measure (N_act), it
 *  determine the quantization factor for the next macroblock.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   the "currentVirtBuf" variable
 *
 * NOTES:
 *
 *===========================================================================*/
void checkBufferFullness (oldQScale)
     int oldQScale;
{
  int temp;
  
  temp = lastFrameVirtBuf + rc_totalFrameBits;
  temp -=  (current_Tx * rc_numBlocks / MB_cnt);
  currentVirtBuf = temp;
  
  rc_Q = (currentVirtBuf * 31 / reactionParameter);
  return;
}


/*===========================================================================*
 *
 * void checkSpatialActivity()
 *
 *      Calcualtes the spatial activity for the four luminance blocks of the
 *	macroblock.  Along with the normalised reference quantization parameter 
 *  (rc_Q) , it determines the quantization factor for the next macroblock.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   the Adaptive quantization variables- act_j, N_act.
 *
 * NOTES:
 *
 *===========================================================================*/
void checkSpatialActivity(blk0, blk1, blk2, blk3)
     Block blk0;
     Block blk1;
     Block blk2;
     Block blk3;
{
  int temp;
  int16 *blkArray[4]; 
  int16 *curBlock;
  int16 *blk_ptr;
  int var[4];
  int i, j;
  
  
  blkArray[0] = (int16 *) blk0;
  blkArray[1] = (int16 *) blk1;
  blkArray[2] = (int16 *) blk2;
  blkArray[3] = (int16 *) blk3;
  
  
  for (i =0; i < 4; i++) {	/* Compute the activity in each block */
    curBlock = blkArray[i];
    blk_ptr = curBlock;
    P_mean = 0;
    /*  Find the mean pixel value */
    for (j=0; j < DCTSIZE_SQ; j ++) {
      P_mean += *(blk_ptr++);
      /*			P_mean += curBlock[j]; 
				if (curBlock[j] != *(blk_ptr++)) {
				printf("ARRAY ERROR: block %d\n", j);
				}
				*/
    }
    P_mean /= DCTSIZE_SQ;
    
    /*  Now find the variance  */
    curBlock = blkArray[i];
    blk_ptr = curBlock;
    var[i] = 0;
    for (j=0; j < DCTSIZE_SQ; j++) {
#ifdef notdef
      if (curBlock[j] != *(blk_ptr++)) {
	printf("ARRAY ERROR: block %d\n", j);
      }
      temp = curBlock[j] - P_mean;
#endif      
      temp = *(blk_ptr++) - P_mean;
      var[i] += (temp * temp);
    }
    var[i] /= DCTSIZE_SQ;
  }
  
  /*  Choose the minimum variance from the 4 blocks and use as the activity */
  var_sblk  = var[0];
  for (i=1; i < 4; i++) {
    var_sblk = (var_sblk < var[i] ? var_sblk : var[i]);
  }
  
  
  act_j = 1 + var_sblk;
  total_act_j += act_j;
  temp = (2 * act_j + avg_act);
  N_act = ( (float) temp / (float) (act_j + 2*avg_act) );
  
  return;
}




/*============================================================================*
 *
 * getRateMode ()
 *
 *      Returns the rate mode- interpreted as either Fixed or Variable
 *
 * RETURNS:     integer
 *
 * SIDE EFFECTS:   none
 *
 *
 *==========================================================================*/
int getRateMode()
{
  return RateControlMode;
}


/*===========================================================================*
 *
 * setBitRate ()
 *
 *      Checks the string parsed from the parameter file.  Verifies
 *  number and sets global values. MPEG standard specifies that bit rate
 *	be rounded up to nearest 400 bits/sec.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   global variables
 *
 * NOTES:	Should this be in the 400-bit units used in sequence header?
 *
 *===========================================================================*/
void setBitRate (const char * const charPtr)
{
  int rate, rnd;
  
  rate = atoi(charPtr);
  if (rate > 0) {
    RateControlMode = FIXED_RATE;
  } else {
    printf("Parameter File Error:  invalid BIT_RATE: \"%s\", defaults to Variable ratemode\n",
	   charPtr);
    RateControlMode = VARIABLE_RATE;
    bit_rate = -1;
  }
  rnd = (rate % 400);
  rate += (rnd ? 400 -rnd : 0); /* round UP to nearest 400 bps */
  rate = (rate > MAX_BIT_RATE ? MAX_BIT_RATE : rate);
  bit_rate = rate;
  DBG_PRINT(("Bit rate is: %d\n", bit_rate));
} 



/*===========================================================================*
 *
 * getBitRate ()
 *
 *      Returns the bit rate read from the parameter file.  This is the
 *  real rate in bits per second, not in 400 bit units as is written to
 *  the sequence header.
 *
 * RETURNS:     int (-1 if Variable mode operation)
 *
 * SIDE EFFECTS:   none
 *
 *===========================================================================*/
int getBitRate ()
{
  return bit_rate;
}




/*===========================================================================*
 *
 * setBufferSize ()
 *
 *      Checks the string parsed from the parameter file.  Verifies
 *  number and sets global values.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   buffer_size global variable.
 *
 * NOTES:	The global is in bits, NOT the 16kb units used in sequence header
 *
 *===========================================================================*/
void setBufferSize (const char * const charPtr)
{
  int size;
  
  size = atoi(charPtr);
  size = (size > MAX_BUFFER_SIZE ? MAX_BUFFER_SIZE : size);
  if (size > 0) {
    size = (16*1024) * ((size + (16*1024 - 1)) / (16*1024));
    buffer_size = size;
  } else {
    buffer_size = DEFAULT_BUFFER_SIZE;
    printf("Parameter File Error:  invalid BUFFER_SIZE: \"%s\", defaults to : %d\n",
	   charPtr, buffer_size);
  }
  DBG_PRINT(("Buffer size is: %d\n", buffer_size));
}


/*===========================================================================*
 *
 * getBufferSize ()
 *
 *      returns the buffer size read from the parameter file.  Size is
 *  in bits- not in units of 16k as written to the sequence header.
 *
 * RETURNS:     int (or -1 if invalid)
 *
 * SIDE EFFECTS:   none
 *
 *===========================================================================*/
int getBufferSize ()
{
  return buffer_size;
}