/* * Copyright (C) 2007-2008 ARM Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ /** * * File Name: omxVCM4P2_EncodeMV.c * OpenMAX DL: v1.0.2 * Revision: 9641 * Date: Thursday, February 7, 2008 * * * * * Description: * Contains module for predicting MV of MB * */ #include "omxtypes.h" #include "armOMX.h" #include "omxVC.h" #include "armCOMM.h" #include "armCOMM_Bitstream.h" #include "armVCM4P2_Huff_Tables_VLC.h" /** * Function: omxVCM4P2_EncodeMV (6.2.4.5.4) * * Description: * Predicts a motion vector for the current macroblock, encodes the * difference, and writes the output to the stream buffer. The input MVs * pMVCurMB, pSrcMVLeftMB, pSrcMVUpperMB, and pSrcMVUpperRightMB should lie * within the ranges associated with the input parameter fcodeForward, as * described in [ISO14496-2], subclause 7.6.3. This function provides a * superset of the functionality associated with the function * omxVCM4P2_FindMVpred. * * Input Arguments: * * ppBitStream - double pointer to the current byte in the bitstream buffer * pBitOffset - index of the first free (next available) bit in the stream * buffer referenced by *ppBitStream, valid in the range 0 to 7. * pMVCurMB - pointer to the current macroblock motion vector; a value of * NULL indicates unavailability. * pSrcMVLeftMB - pointer to the source left macroblock motion vector; a * value of NULLindicates unavailability. * pSrcMVUpperMB - pointer to source upper macroblock motion vector; a * value of NULL indicates unavailability. * pSrcMVUpperRightMB - pointer to source upper right MB motion vector; a * value of NULL indicates unavailability. * fcodeForward - an integer with values from 1 to 7; used in encoding * motion vectors related to search range, as described in * [ISO14496-2], subclause 7.6.3. * MBType - macro block type, valid in the range 0 to 5 * * Output Arguments: * * ppBitStream - updated pointer to the current byte in the bit stream * buffer * pBitOffset - updated index of the next available bit position in stream * buffer referenced by *ppBitStream * * Return Value: * * OMX_Sts_NoErr - no error * OMX_Sts_BadArgErr - bad arguments * - At least one of the following pointers is NULL: ppBitStream, * *ppBitStream, pBitOffset, pMVCurMB * - *pBitOffset < 0, or *pBitOffset >7. * - fcodeForward <= 0, or fcodeForward > 7, or MBType < 0. * */ OMXResult omxVCM4P2_EncodeMV( OMX_U8 **ppBitStream, OMX_INT *pBitOffset, const OMXVCMotionVector * pMVCurMB, const OMXVCMotionVector * pSrcMVLeftMB, const OMXVCMotionVector * pSrcMVUpperMB, const OMXVCMotionVector * pSrcMVUpperRightMB, OMX_INT fcodeForward, OMXVCM4P2MacroblockType MBType ) { OMXVCMotionVector dstMVPred, diffMV; OMXVCMotionVector dstMVPredME[12]; /* Initialized to remove compilation warning */ OMX_INT iBlk, i, count = 1; OMX_S32 mvHorResidual, mvVerResidual, mvHorData, mvVerData; OMX_U8 scaleFactor, index; /* Argument error checks */ armRetArgErrIf(ppBitStream == NULL, OMX_Sts_BadArgErr); armRetArgErrIf(*ppBitStream == NULL, OMX_Sts_BadArgErr); armRetArgErrIf(pBitOffset == NULL, OMX_Sts_BadArgErr); armRetArgErrIf(pMVCurMB == NULL, OMX_Sts_BadArgErr); armRetArgErrIf(((*pBitOffset < 0) || (*pBitOffset > 7)), OMX_Sts_BadArgErr); armRetArgErrIf(((fcodeForward < 1) || (fcodeForward > 7)), \ OMX_Sts_BadArgErr); if ((MBType == OMX_VC_INTRA) || (MBType == OMX_VC_INTRA_Q) ) { /* No candidate vectors hence make them zero */ for (i = 0; i < 12; i++) { dstMVPredME[i].dx = 0; dstMVPredME[i].dy = 0; } return OMX_Sts_NoErr; } if ((MBType == OMX_VC_INTER4V) || (MBType == OMX_VC_INTER4V_Q)) { count = 4; } else if ((MBType == OMX_VC_INTER) || (MBType == OMX_VC_INTER_Q)) { count = 1; } /* Calculating the scale factor */ scaleFactor = 1 << (fcodeForward -1); for (iBlk = 0; iBlk < count; iBlk++) { /* Find the predicted vector */ omxVCM4P2_FindMVpred ( pMVCurMB, pSrcMVLeftMB, pSrcMVUpperMB, pSrcMVUpperRightMB, &dstMVPred, dstMVPredME, iBlk ); /* Calculating the differential motion vector (diffMV) */ diffMV.dx = pMVCurMB[iBlk].dx - dstMVPred.dx; diffMV.dy = pMVCurMB[iBlk].dy - dstMVPred.dy; /* Calculating the mv_data and mv_residual for Horizantal MV */ if (diffMV.dx == 0) { mvHorResidual = 0; mvHorData = 0; } else { mvHorResidual = ( armAbs(diffMV.dx) - 1) % scaleFactor; mvHorData = (armAbs(diffMV.dx) - mvHorResidual + (scaleFactor - 1)) / scaleFactor; if (diffMV.dx < 0) { mvHorData = -mvHorData; } } /* Calculating the mv_data and mv_residual for Vertical MV */ if (diffMV.dy == 0) { mvVerResidual = 0; mvVerData = 0; } else { mvVerResidual = ( armAbs(diffMV.dy) - 1) % scaleFactor; mvVerData = (armAbs(diffMV.dy) - mvVerResidual + (scaleFactor - 1)) / scaleFactor; if (diffMV.dy < 0) { mvVerData = -mvVerData; } } /* Huffman encoding */ /* The index is actually calculate as index = ((float) (mvHorData/2) + 16) * 2, meaning the MV data is halfed and then normalized to begin with zero and then doubled to take care of indexing the fractional part included */ index = mvHorData + 32; armPackVLC32 (ppBitStream, pBitOffset, armVCM4P2_aVlcMVD[index]); if ((fcodeForward > 1) && (diffMV.dx != 0)) { armPackBits (ppBitStream, pBitOffset, mvHorResidual, (fcodeForward -1)); } /* The index is actually calculate as index = ((float) (mvVerData/2) + 16) * 2, meaning the MV data is halfed and then normalized to begin with zero and then doubled to take care of indexing the fractional part included */ index = mvVerData + 32; armPackVLC32 (ppBitStream, pBitOffset, armVCM4P2_aVlcMVD[index]); if ((fcodeForward > 1) && (diffMV.dy != 0)) { armPackBits (ppBitStream, pBitOffset, mvVerResidual, (fcodeForward -1)); } } return OMX_Sts_NoErr; } /* End of file */