/* * 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_DecodePadMV_PVOP.c * OpenMAX DL: v1.0.2 * Revision: 9641 * Date: Thursday, February 7, 2008 * * * * * Description: * Contains module for decoding MV and padding the same * */ #include "omxtypes.h" #include "armOMX.h" #include "omxVC.h" #include "armCOMM_Bitstream.h" #include "armCOMM.h" #include "armVCM4P2_Huff_Tables_VLC.h" /** * Function: omxVCM4P2_DecodePadMV_PVOP (6.2.5.1.1) * * Description: * Decodes and pads the four motion vectors associated with a non-intra P-VOP * macroblock. For macroblocks of type OMX_VC_INTER4V, the output MV is * padded as specified in [ISO14496-2], subclause 7.6.1.6. Otherwise, for * macroblocks of types other than OMX_VC_INTER4V, the decoded MV is copied to * all four output MV buffer entries. * * Input Arguments: * * ppBitStream - pointer to the pointer to the current byte in the bit * stream buffer * pBitOffset - pointer to the bit position in the byte pointed to by * *ppBitStream. *pBitOffset is valid within [0-7]. * pSrcMVLeftMB, pSrcMVUpperMB, and pSrcMVUpperRightMB - pointers to the * motion vector buffers of the macroblocks specially at the left, * upper, and upper-right side of the current macroblock, * respectively; a value of NULL indicates unavailability. Note: * Any neighborhood macroblock outside the current VOP or video * packet or outside the current GOB (when short_video_header is * 1 ) for which gob_header_empty is 0 is treated as * transparent, according to [ISO14496-2], subclause 7.6.5. * fcodeForward - a code equal to vop_fcode_forward in MPEG-4 bit stream * syntax * MBType - the type of the current macroblock. If MBType is not equal to * OMX_VC_INTER4V, the destination motion vector buffer is still * filled with the same decoded vector. * * Output Arguments: * * ppBitStream - *ppBitStream is updated after the block is decoded, so * that it points to the current byte in the bit stream buffer * pBitOffset - *pBitOffset is updated so that it points to the current bit * position in the byte pointed by *ppBitStream * pDstMVCurMB - pointer to the motion vector buffer for the current * macroblock; contains four decoded motion vectors * * Return Value: * * OMX_Sts_NoErr - no error * OMX_Sts_BadArgErr - bad arguments: * - At least one of the following pointers is NULL: * ppBitStream, *ppBitStream, pBitOffset, pDstMVCurMB * - *pBitOffset exceeds [0,7] * - fcodeForward exceeds (0,7] * - MBType less than zero * - motion vector buffer is not 4-byte aligned. * OMX_Sts_Err - status error * */ OMXResult omxVCM4P2_DecodePadMV_PVOP( const OMX_U8 ** ppBitStream, OMX_INT * pBitOffset, OMXVCMotionVector * pSrcMVLeftMB, OMXVCMotionVector *pSrcMVUpperMB, OMXVCMotionVector * pSrcMVUpperRightMB, OMXVCMotionVector * pDstMVCurMB, OMX_INT fcodeForward, OMXVCM4P2MacroblockType MBType ) { OMXVCMotionVector diffMV; OMXVCMotionVector dstMVPredME[12]; OMX_INT iBlk, i, count = 1; OMX_S32 mvHorResidual = 1, mvVerResidual = 1, mvHorData, mvVerData; OMX_S8 scaleFactor, index; OMX_S16 high, low, range; /* Argument error checks */ armRetArgErrIf(ppBitStream == NULL, OMX_Sts_BadArgErr); armRetArgErrIf(*ppBitStream == NULL, OMX_Sts_BadArgErr); armRetArgErrIf(pBitOffset == NULL, OMX_Sts_BadArgErr); armRetArgErrIf(pDstMVCurMB == NULL, OMX_Sts_BadArgErr); armRetArgErrIf(((*pBitOffset < 0) || (*pBitOffset > 7)), OMX_Sts_BadArgErr); armRetArgErrIf(((fcodeForward < 1) || (fcodeForward > 7)), \ OMX_Sts_BadArgErr); armRetArgErrIf(!armIs4ByteAligned(pDstMVCurMB), OMX_Sts_BadArgErr); if ((MBType == OMX_VC_INTRA) || (MBType == OMX_VC_INTRA_Q) ) { /* All MV's are zero */ for (i = 0; i < 4; i++) { pDstMVCurMB[i].dx = 0; pDstMVCurMB[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); high = ( 32 * scaleFactor) - 1; low = ( (-32) * scaleFactor); range = ( 64 * scaleFactor); /* Huffman decoding and MV reconstruction */ for (iBlk = 0; iBlk < count; iBlk++) { /* Huffman decoding to get Horizontal data and residual */ index = armUnPackVLC32(ppBitStream, pBitOffset, armVCM4P2_aVlcMVD); armRetDataErrIf(index == -1, OMX_Sts_Err); mvHorData = index - 32; if ((fcodeForward > 1) && (mvHorData != 0)) { mvHorResidual = (OMX_S32) armGetBits(ppBitStream, pBitOffset, (fcodeForward -1)); } /* Huffman decoding to get Vertical data and residual */ index = armUnPackVLC32(ppBitStream, pBitOffset, armVCM4P2_aVlcMVD); armRetDataErrIf(index == -1, OMX_Sts_Err); mvVerData = index - 32; if ((fcodeForward > 1) && (mvVerData != 0)) { mvVerResidual = (OMX_S32) armGetBits(ppBitStream, pBitOffset, (fcodeForward -1)); } /* Calculating the differtial MV */ if ( (scaleFactor == 1) || (mvHorData == 0) ) { diffMV.dx = mvHorData; } else { diffMV.dx = ((armAbs(mvHorData) - 1) * fcodeForward) + mvHorResidual + 1; if (mvHorData < 0) { diffMV.dx = -diffMV.dx; } } if ( (scaleFactor == 1) || (mvVerData == 0) ) { diffMV.dy = mvVerData; } else { diffMV.dy = ((armAbs(mvVerData) - 1) * fcodeForward) + mvVerResidual + 1; if (mvVerData < 0) { diffMV.dy = -diffMV.dy; } } /* Find the predicted vector */ omxVCM4P2_FindMVpred ( pDstMVCurMB, pSrcMVLeftMB, pSrcMVUpperMB, pSrcMVUpperRightMB, &pDstMVCurMB[iBlk], dstMVPredME, iBlk); /* Adding the difference to the predicted MV to reconstruct MV */ pDstMVCurMB[iBlk].dx += diffMV.dx; pDstMVCurMB[iBlk].dy += diffMV.dy; /* Checking the range and keeping it within the limits */ if ( pDstMVCurMB[iBlk].dx < low ) { pDstMVCurMB[iBlk].dx += range; } if (pDstMVCurMB[iBlk].dx > high) { pDstMVCurMB[iBlk].dx -= range; } if ( pDstMVCurMB[iBlk].dy < low ) { pDstMVCurMB[iBlk].dy += range; } if (pDstMVCurMB[iBlk].dy > high) { pDstMVCurMB[iBlk].dy -= range; } } if ((MBType == OMX_VC_INTER) || (MBType == OMX_VC_INTER_Q)) { pDstMVCurMB[1] = pDstMVCurMB[0]; pDstMVCurMB[2] = pDstMVCurMB[0]; pDstMVCurMB[3] = pDstMVCurMB[0]; } return OMX_Sts_NoErr; } /* End of file */