1 /** 2 * 3 * File Name: omxVCM4P2_DecodeBlockCoef_Intra.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 modules for intra reconstruction 14 * 15 */ 16 17 #include "omxtypes.h" 18 #include "armOMX.h" 19 #include "omxVC.h" 20 21 #include "armCOMM.h" 22 #include "armVC.h" 23 24 /** 25 * Function: omxVCM4P2_DecodeBlockCoef_Intra 26 * 27 * Description: 28 * Decodes the INTRA block coefficients. Inverse quantization, inversely zigzag 29 * positioning, and IDCT, with appropriate clipping on each step, are performed 30 * on the coefficients. The results are then placed in the output frame/plane on 31 * a pixel basis. For INTRA block, the output values are clipped to [0, 255] and 32 * written to corresponding block buffer within the destination plane. 33 * 34 * Remarks: 35 * 36 * Parameters: 37 * [in] ppBitStream pointer to the pointer to the current byte in 38 * the bit stream buffer. There is no boundary 39 * check for the bit stream buffer. 40 * [in] pBitOffset pointer to the bit position in the byte pointed 41 * to by *ppBitStream. *pBitOffset is valid within 42 * [0-7]. 43 * [in] step width of the destination plane 44 * [in/out] pCoefBufRow [in] pointer to the coefficient row buffer 45 * [out] updated coefficient rwo buffer 46 * [in/out] pCoefBufCol [in] pointer to the coefficient column buffer 47 * [out] updated coefficient column buffer 48 * [in] curQP quantization parameter of the macroblock which 49 * the current block belongs to 50 * [in] pQpBuf Pointer to a 2-element QP array. pQpBuf[0] holds the QP of the 8x8 block left to 51 * the current block(QPa). pQpBuf[1] holds the QP of the 8x8 block just above the 52 * current block(QPc). 53 * Note, in case the corresponding block is out of VOP bound, the QP value will have 54 * no effect to the intra-prediction process. Refer to subclause "7.4.3.3 Adaptive 55 * ac coefficient prediction" of ISO/IEC 14496-2(MPEG4 Part2) for accurate description. 56 * [in] blockIndex block index indicating the component type and 57 * position as defined in subclause 6.1.3.8, 58 * Figure 6-5 of ISO/IEC 14496-2. 59 * [in] intraDCVLC a code determined by intra_dc_vlc_thr and QP. 60 * This allows a mechanism to switch between two VLC 61 * for coding of Intra DC coefficients as per Table 62 * 6-21 of ISO/IEC 14496-2. 63 * [in] ACPredFlag a flag equal to ac_pred_flag (of luminance) indicating 64 * if the ac coefficients of the first row or first 65 * column are differentially coded for intra coded 66 * macroblock. 67 * [in] shortVideoHeader a flag indicating presence of short_video_header; 68 * shortVideoHeader==1 selects linear intra DC mode, 69 * and shortVideoHeader==0 selects nonlinear intra DC mode. 70 * [out] ppBitStream *ppBitStream is updated after the block is 71 * decoded, so that it points to the current byte 72 * in the bit stream buffer 73 * [out] pBitOffset *pBitOffset is updated so that it points to the 74 * current bit position in the byte pointed by 75 * *ppBitStream 76 * [out] pDst pointer to the block in the destination plane. 77 * pDst should be 16-byte aligned. 78 * [out] pCoefBufRow pointer to the updated coefficient row buffer. 79 * 80 * Return Value: 81 * OMX_Sts_NoErr - no error 82 * OMX_Sts_BadArgErr - bad arguments 83 * - At least one of the following pointers is NULL: ppBitStream, *ppBitStream, pBitOffset, 84 * pCoefBufRow, pCoefBufCol, pQPBuf, pDst. 85 * or 86 * - At least one of the below case: *pBitOffset exceeds [0,7], curQP exceeds (1, 31), 87 * blockIndex exceeds [0,9], step is not the multiple of 8, intraDCVLC is zero while 88 * blockIndex greater than 5. 89 * or 90 * - pDst is not 16-byte aligned 91 * OMX_Sts_Err - status error 92 * 93 */ 94 95 OMXResult omxVCM4P2_DecodeBlockCoef_Intra( 96 const OMX_U8 ** ppBitStream, 97 OMX_INT *pBitOffset, 98 OMX_U8 *pDst, 99 OMX_INT step, 100 OMX_S16 *pCoefBufRow, 101 OMX_S16 *pCoefBufCol, 102 OMX_U8 curQP, 103 const OMX_U8 *pQPBuf, 104 OMX_INT blockIndex, 105 OMX_INT intraDCVLC, 106 OMX_INT ACPredFlag, 107 OMX_INT shortVideoHeader 108 ) 109 { 110 OMX_S16 tempBuf1[79], tempBuf2[79]; 111 OMX_S16 *pTempBuf1, *pTempBuf2; 112 OMX_INT predDir, predACDir; 113 OMX_INT predQP; 114 OMXVCM4P2VideoComponent videoComp; 115 OMXResult errorCode; 116 117 118 /* Aligning the local buffers */ 119 pTempBuf1 = armAlignTo16Bytes(tempBuf1); 120 pTempBuf2 = armAlignTo16Bytes(tempBuf2); 121 122 /* Setting the AC prediction direction and prediction direction */ 123 armVCM4P2_SetPredDir( 124 blockIndex, 125 pCoefBufRow, 126 pCoefBufCol, 127 &predDir, 128 &predQP, 129 pQPBuf); 130 131 predACDir = predDir; 132 133 134 if (ACPredFlag == 0) 135 { 136 predACDir = OMX_VC_NONE; 137 } 138 139 /* Setting the videoComp */ 140 if (blockIndex <= 3) 141 { 142 videoComp = OMX_VC_LUMINANCE; 143 } 144 else 145 { 146 videoComp = OMX_VC_CHROMINANCE; 147 } 148 149 150 /* VLD and zigzag */ 151 if (intraDCVLC == 1) 152 { 153 errorCode = omxVCM4P2_DecodeVLCZigzag_IntraDCVLC( 154 ppBitStream, 155 pBitOffset, 156 pTempBuf1, 157 predACDir, 158 shortVideoHeader, 159 videoComp); 160 armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); 161 } 162 else 163 { 164 errorCode = omxVCM4P2_DecodeVLCZigzag_IntraACVLC( 165 ppBitStream, 166 pBitOffset, 167 pTempBuf1, 168 predACDir, 169 shortVideoHeader); 170 armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); 171 } 172 173 /* AC DC prediction */ 174 errorCode = omxVCM4P2_PredictReconCoefIntra( 175 pTempBuf1, 176 pCoefBufRow, 177 pCoefBufCol, 178 curQP, 179 predQP, 180 predDir, 181 ACPredFlag, 182 videoComp); 183 armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); 184 185 /* Dequantization */ 186 errorCode = omxVCM4P2_QuantInvIntra_I( 187 pTempBuf1, 188 curQP, 189 videoComp, 190 shortVideoHeader); 191 armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); 192 193 /* Inverse transform */ 194 errorCode = omxVCM4P2_IDCT8x8blk (pTempBuf1, pTempBuf2); 195 armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); 196 197 /* Placing the linear array into the destination plane and clipping 198 it to 0 to 255 */ 199 200 armVCM4P2_Clip8(pTempBuf2,pDst,step); 201 202 203 return OMX_Sts_NoErr; 204 } 205 206 /* End of file */ 207 208 209
