motcomp.c

Nokia H.264/AVC Encoder/Decoder Usage Manual

/*
COPYRIGHT, LICENSE AND WARRANTY INFORMATION

This software module has been originally developed by Nokia Corporation. 

Provided that a person, entity or a company willing to use the Software 
(hereinafter Licensee) comply with all the terms and conditions of this 
Statement and subject to the limitations set forth in this Statement Nokia 
grants to such Licensee a non-exclusive, sub-licensable, worldwide, 
limited license under copyrights owned by Nokia to use the Software for 
the sole purpose of creating, manufacturing, selling, marketing, or  
distributing (including the right to make modifications to the Software) 
a fully compliant decoder implementation (hereinafter "Decoder") of 
ITU-T Recommendation H.264 / ISO/IEC International Standard 14496-10 and 
an encoder implementation producing output that is decodable with the 
Decoder.

Nokia retains the ownership of copyrights to the Software. There is no 
patent nor other intellectual property right of Nokia licensed under this 
Statement (except the copyright license above). Licensee hereby assumes 
sole responsibility to secure any other intellectual property rights 
needed, if any. For example, if patent licenses  are required, it is 
their responsibility to acquire the license before utilizing the Software.

The license by Nokia is subject to that the Licensee grants to Nokia the 
non-exclusive, worldwide, royalty-free, perpetual and irrevocable 
covenant that the Licensee(s) shall not bring a suit before any court or 
administrative agency or otherwise assert a claim for infringement under 
the Licensee intellectual property rights that, but for a license, would 
be infringed by the Software against  
   (a)  Nokia or Nokia's Affiliate; or  
   (b)  other recipient of a license and covenant not to sue with respect 
        to the Software from Nokia; or 
   (c)  contractor, customer or distributor of a party listed above in a 
        or b,  
which suit or claim is related to the Software or use thereof.

The Licensee(s) further agrees to grant a reciprocal license to Nokia 
(as granted by Nokia to the Licensee(s) on the modifications made by 
Licensee(s) to the Software. 

THE SOFTWARE IS PROVIDED "AS IS" AND THE ORIGINAL DEVELOPER DISCLAIMS 
ANY AND ALL WARRANTIES WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING 
BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS 
FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. THOSE INTENDING TO USE 
THE SOFTWARE ARE EXPRESSLY ADVISED THAT ITS USE MAY INFRINGE EXISTING 
PATENTS AND BE SUBJECT TO ROYALTY PAYMENTS TO PATENT OWNERS. ANYONE 
USING THE SOFTWARE ON THE BASIS OF THIS LICENSE AGREES TO OBTAIN THE 
NECESSARY PERMISSIONS FROM ANY AND ALL APPLICABLE PATENT OWNERS FOR SUCH 
USE.

IN NO EVENT SHALL THE ORIGINAL DEVELOPER BE LIABLE FOR ANY CLAIM, 
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT 
OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE 
OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

This copyright, license and warranty information notice must be retained 
in all copies and derivative works of the Software or substantial 
portions thereof.
*/



#include <limits.h>
#include "globals.h"
#include "vlcutility.h"
#include "macroblock.h"


const int8 modeBlkIndices[5][4] = 
{
  {0, 0, 0, 0},
  {0, 0, 0, 0},
  {0, 8, 0, 0},
  {0, 2, 0, 0},
  {0, 2, 8, 10},
};


// the first element is always reserved
int8 modeNumBlocks[8] =
{
  16, 16, 8, 8, 4, 2, 2, 1
};


int8 modePartWidth[8] =
{
  4, 4, 4, 2, 2, 2, 1, 1
};

int8 modePartHeight[8] =
{
  4, 4, 2, 4, 2, 1, 2, 1
};

#define NA      -2


#define MEDIAN(med, a0, a1, a2)   {             \
    if ((a0) > (a1)) {                          \
      if (a1 > (a2))        (med) = (a1);       \
      else if ((a0) > (a2))  (med) = (a2);       \
      else                  (med) = (a0);       \
    } else if ((a0) > (a2))  (med) = (a0);       \
    else if ((a1) > (a2))    (med) = (a2);       \
    else                    (med) = (a1);       \
  }


static const int8 trIdx[8] = {0, 0, 0, 1, 1, 1, 2, 2};


/*
 *
 * mcpFindPredMv:
 *
 * Parameters:
 *      pMb               Macroblock information
 *      refNum            Reference frame index for this partition
 *      mode              Indicate size of partition
 *      blkAddr           Addr of 1st block of partition in 4x4 block array
 *
 * Function:
 *      Calculate the MV predictor. 
 *
 * Returns:
 *      -
 *
 */
motVec_s mcpFindPredMv(macroblock_s *pMb,
                       int          refNum,
                       int          mode,
                       int          blkAddr)
{
  motVec_s vecA;
  motVec_s vecB;
  motVec_s vecC;
  motVec_s vecX;
  int refLeft, refUp, refUpRight;
  int numEqualRefs;
  blkState_s *blkLeft, *blkUp, *blkUpRight;

  /*
   * Fetch vectors and reference frame numbers of blocks A, B and C
   */
  blkLeft    = pMb->blkLeft[blkAddr];
  blkUp      = pMb->blkUp[blkAddr];
  blkUpRight = pMb->blkUpRight[trIdx[mode]][blkAddr];

  refLeft    = blkLeft->ref == refNum;
  vecA       = blkLeft->mv;
  refUp      = blkUp->ref == refNum;
  vecB       = blkUp->mv;
  refUpRight = blkUpRight->ref == refNum;
  vecC       = blkUpRight->mv;

  numEqualRefs = refLeft + refUp + refUpRight;

  // put the most common case in the front
  if ((mode > MOT_8x16) && (numEqualRefs > 1))
  {
    // performa median filtering
    MEDIAN(vecX.x, vecA.x, vecB.x, vecC.x);
    MEDIAN(vecX.y, vecA.y, vecB.y, vecC.y);
  }
  else
  {
    // directional prediction
    if (mode == MOT_16x8)
    {
      if (blkAddr == 0)
      {
        if (refUp)
          return vecB;
      }
      else 
      {
        if (refLeft)
          return vecA;
      }
    }
    else if (mode == MOT_8x16)
    {
      if (blkAddr == 0)
      {
        if (refLeft)
          return vecA;
      }
      else
      {
        // this could be real upRight, or upRight replaced by upLeft
        if (refUpRight)
          return vecC;
      }
    }

    /*
    * If only one of the neighboring block has the same reference
    * frame number as the  current block, predict from that block.
    */

    // this is of little probabability, make it faster
    if (numEqualRefs == 1)
    {
      if (refLeft)
        vecX = vecA;
      else if (refUp)
        vecX = vecB;
      else
        vecX = vecC;
    }
    else if ((blkUp->ref == REF_NA) && (blkUpRight->ref == REF_NA) && (blkLeft->ref >= 0))
    {
      // if only vecA is available, vecA is set as the predictor
      vecX = vecA;
    }
    else
    {
      // performa median filtering
      MEDIAN(vecX.x, vecA.x, vecB.x, vecC.x);
      MEDIAN(vecX.y, vecA.y, vecB.y, vecC.y);
    }
  }

  return vecX;
}



/*
 * mcpFindDiffMvs:
 *
 * Parameters:
 *      pMb                 Macroblock information
 *      refIdxRange         Information related to motion estimation
 *
 * Function:
 *      Calculate the differential motion vectors and referenace frame indices
 *      for all MB partitions. We use the index tables to find the position of
 *      the first 4x4 block within the partition.
 *
 * Returns:
 *      -
 */
int mcpFindDiffMvs(macroblock_s *pMb,
                   int          refIdxRange)
{
  int i, mpIdx, mpBlkAddr, blkAddr;
  int mpBlkCount;
  int mvBits, interMode, subMbMode, blkMode;
  int numVecs, lastNumVecs;
  motVec_s predVec;
  blkState_s *mrPair, *blkInfo;

  mvBits  = 0;
  numVecs = 0;

  interMode  = pMb->interMode;
  subMbMode  = 0;
  mpBlkCount = 1;
  blkInfo    = & pMb->current[0][0];

  for (mpIdx = 0; mpIdx < numOfRefPar[interMode - 1]; mpIdx ++)
  {
    mpBlkAddr = modeBlkIndices[interMode][mpIdx];
    blkAddr   = mpBlkAddr;

    pMb->refIndices[mpIdx] = (u_int8) blkInfo[mpBlkAddr].ref;
    mvBits += vlcGetRefIndexBits(refIdxRange, pMb->refIndices[mpIdx]);

    if (interMode == MOT_8x8)
    {
      // make index this way to use the same tables
      subMbMode  = pMb->interSubMbModes[mpIdx];
      mpBlkCount = numOfRefPar[subMbMode];
    }
    blkMode = interMode + subMbMode;

    lastNumVecs = numVecs;
    numVecs += mpBlkCount;
    for (i = lastNumVecs; i < numVecs; i ++)
    {
      if (interMode == MOT_8x8)