1 /** 2 * 3 * File Name: armVCM4P10_CompareMotionCostToMV.c 4 * OpenMAX DL: v1.0.2 5 * Revision: 9641 6 * Date: Thursday, February 7, 2008 7 * 8 * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved. 9 * 10 * 11 * 12 * Description: 13 * Contains module for comparing motion vectors and SAD's to decide 14 * the best MV and SAD 15 * 16 */ 17 18 #include "omxtypes.h" 19 #include "armOMX.h" 20 21 #include "armVC.h" 22 #include "armCOMM.h" 23 24 /** 25 * Function: armVCM4P10_ExpGolBitsUsed 26 * 27 * Description: 28 * Performs calculating Exp-Golomb code length for a given values 29 * 30 * Remarks: 31 * 32 * Parameters: 33 * [in] val Signed number for which Exp-Golomb code length has 34 * to be calculated 35 * 36 * Return Value: 37 * Returns the length of the Exp-Golomb code for val 38 */ 39 40 static OMX_U16 armVCM4P10_ExpGolBitsUsed (OMX_S16 val) 41 { 42 OMX_U16 sizeCodeNum, codeNum; 43 44 /* Mapping val to codeNum */ 45 codeNum = armAbs (val); 46 if (val > 0) 47 { 48 codeNum = (2 * codeNum) - 1; 49 } 50 else 51 { 52 codeNum = 2 * codeNum; 53 } 54 55 /* Size of the exp-golomb code */ 56 sizeCodeNum = (2 * armLogSize (codeNum + 1)) - 1; 57 58 return sizeCodeNum; 59 } 60 61 62 /** 63 * Function: armVCM4P10_CompareMotionCostToMV 64 * 65 * Description: 66 * Performs comparision of motion vectors and Motion cost to decide the 67 * best MV and best MC 68 * 69 * Remarks: 70 * 71 * Parameters: 72 * [in] mvX x coordinate of the candidate motion vector in 1/4 pel units 73 * [in] mvY y coordinate of the candidate motion vector in 1/4 pel units 74 * [in] diffMV differential MV 75 * [in] candSAD Candidate SAD 76 * [in] bestMV Best MV, contains best MV till the previous interation. 77 * [in] nLamda Lamda factor; used to compute motion cost 78 * [in] *pBestCost Contains the current best motion cost. 79 * [out] *pBestCost pBestCost Motion cost will be associated with the best MV 80 * after judgement; 81 * computed as SAD+Lamda*BitsUsedByMV, if the candCost is less 82 * than the best cost passed then the *pBestCost will be equal to candCost 83 * [out] bestMV Finally will have the best MV after the judgement. 84 * 85 * Return Value: 86 * OMX_INT -- 1 to indicate that the current motion cost is the best 87 * 0 to indicate that it is NOT the best motion cost 88 */ 89 90 OMX_INT armVCM4P10_CompareMotionCostToMV ( 91 OMX_S16 mvX, 92 OMX_S16 mvY, 93 OMXVCMotionVector diffMV, 94 OMX_INT candSAD, 95 OMXVCMotionVector *bestMV, 96 OMX_U32 nLamda, 97 OMX_S32 *pBestCost 98 ) 99 { 100 OMX_S32 candCost; 101 OMX_U16 sizeCodeNum; 102 103 sizeCodeNum = armVCM4P10_ExpGolBitsUsed (diffMV.dx); 104 sizeCodeNum += armVCM4P10_ExpGolBitsUsed (diffMV.dy); 105 106 /* Motion cost = SAD + lamda * ((bitsused(diffMVx) + (bitsused(diffMVy))*/ 107 candCost = candSAD + (nLamda * sizeCodeNum); 108 109 /* Calculate candCost */ 110 if (candCost < *pBestCost) 111 { 112 *pBestCost = candCost; 113 bestMV->dx = mvX; 114 bestMV->dy = mvY; 115 return 1; 116 } 117 if (candCost > *pBestCost) 118 { 119 return 0; 120 } 121 /* shorter motion vector */ 122 if ( (mvX * mvX + mvY * mvY) < ((bestMV->dx * bestMV->dx) + (bestMV->dy * bestMV->dy)) ) 123 { 124 *pBestCost = candCost; 125 bestMV->dx = mvX; 126 bestMV->dy = mvY; 127 return 1; 128 } 129 130 return 0; 131 } 132 133 /*End of File*/ 134
