James Dong | 0c1bc74 | 2011-05-31 18:53:46 -0700 | [diff] [blame] | 1 | /** |
| 2 | * |
| 3 | * File Name: omxVCM4P2_DecodeBlockCoef_Intra.c |
| 4 | * OpenMAX DL: v1.0.2 |
| 5 | * Revision: 12290 |
| 6 | * Date: Wednesday, April 9, 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 | /* Function for saturating 16 bit values to the [0,255] range and */ |
| 25 | /* writing out as 8 bit values. Does 64 entries */ |
| 26 | void armVCM4P2_Clip8(OMX_S16 *pSrc, OMX_U8 *pDst, OMX_INT dstStep ); |
| 27 | |
| 28 | |
| 29 | |
| 30 | /** |
| 31 | * Function: omxVCM4P2_DecodeBlockCoef_Intra |
| 32 | * |
| 33 | * Description: |
| 34 | * Decodes the INTRA block coefficients. Inverse quantization, inversely zigzag |
| 35 | * positioning, and IDCT, with appropriate clipping on each step, are performed |
| 36 | * on the coefficients. The results are then placed in the output frame/plane on |
| 37 | * a pixel basis. For INTRA block, the output values are clipped to [0, 255] and |
| 38 | * written to corresponding block buffer within the destination plane. |
| 39 | * |
| 40 | * Remarks: |
| 41 | * |
| 42 | * Parameters: |
| 43 | * [in] ppBitStream pointer to the pointer to the current byte in |
| 44 | * the bit stream buffer. There is no boundary |
| 45 | * check for the bit stream buffer. |
| 46 | * [in] pBitOffset pointer to the bit position in the byte pointed |
| 47 | * to by *ppBitStream. *pBitOffset is valid within |
| 48 | * [0-7]. |
| 49 | * [in] step width of the destination plane |
| 50 | * [in/out] pCoefBufRow [in] pointer to the coefficient row buffer |
| 51 | * [out] updated coefficient rwo buffer |
| 52 | * [in/out] pCoefBufCol [in] pointer to the coefficient column buffer |
| 53 | * [out] updated coefficient column buffer |
| 54 | * [in] curQP quantization parameter of the macroblock which |
| 55 | * the current block belongs to |
| 56 | * [in] pQpBuf Pointer to a 2-element QP array. pQpBuf[0] holds the QP of the 8x8 block left to |
| 57 | * the current block(QPa). pQpBuf[1] holds the QP of the 8x8 block just above the |
| 58 | * current block(QPc). |
| 59 | * Note, in case the corresponding block is out of VOP bound, the QP value will have |
| 60 | * no effect to the intra-prediction process. Refer to subclause "7.4.3.3 Adaptive |
| 61 | * ac coefficient prediction" of ISO/IEC 14496-2(MPEG4 Part2) for accurate description. |
| 62 | * [in] blockIndex block index indicating the component type and |
| 63 | * position as defined in subclause 6.1.3.8, |
| 64 | * Figure 6-5 of ISO/IEC 14496-2. |
| 65 | * [in] intraDCVLC a code determined by intra_dc_vlc_thr and QP. |
| 66 | * This allows a mechanism to switch between two VLC |
| 67 | * for coding of Intra DC coefficients as per Table |
| 68 | * 6-21 of ISO/IEC 14496-2. |
| 69 | * [in] ACPredFlag a flag equal to ac_pred_flag (of luminance) indicating |
| 70 | * if the ac coefficients of the first row or first |
| 71 | * column are differentially coded for intra coded |
| 72 | * macroblock. |
| 73 | * [in] shortVideoHeader a flag indicating presence of short_video_header; |
| 74 | * shortVideoHeader==1 selects linear intra DC mode, |
| 75 | * and shortVideoHeader==0 selects nonlinear intra DC mode. |
| 76 | * [out] ppBitStream *ppBitStream is updated after the block is |
| 77 | * decoded, so that it points to the current byte |
| 78 | * in the bit stream buffer |
| 79 | * [out] pBitOffset *pBitOffset is updated so that it points to the |
| 80 | * current bit position in the byte pointed by |
| 81 | * *ppBitStream |
| 82 | * [out] pDst pointer to the block in the destination plane. |
| 83 | * pDst should be 16-byte aligned. |
| 84 | * [out] pCoefBufRow pointer to the updated coefficient row buffer. |
| 85 | * |
| 86 | * Return Value: |
| 87 | * OMX_Sts_NoErr - no error |
| 88 | * OMX_Sts_BadArgErr - bad arguments |
| 89 | * - At least one of the following pointers is NULL: ppBitStream, *ppBitStream, pBitOffset, |
| 90 | * pCoefBufRow, pCoefBufCol, pQPBuf, pDst. |
| 91 | * or |
| 92 | * - At least one of the below case: *pBitOffset exceeds [0,7], curQP exceeds (1, 31), |
| 93 | * blockIndex exceeds [0,9], step is not the multiple of 8, intraDCVLC is zero while |
| 94 | * blockIndex greater than 5. |
| 95 | * or |
| 96 | * - pDst is not 16-byte aligned |
| 97 | * OMX_Sts_Err - status error |
| 98 | * |
| 99 | */ |
| 100 | |
| 101 | OMXResult omxVCM4P2_DecodeBlockCoef_Intra( |
| 102 | const OMX_U8 ** ppBitStream, |
| 103 | OMX_INT *pBitOffset, |
| 104 | OMX_U8 *pDst, |
| 105 | OMX_INT step, |
| 106 | OMX_S16 *pCoefBufRow, |
| 107 | OMX_S16 *pCoefBufCol, |
| 108 | OMX_U8 curQP, |
| 109 | const OMX_U8 *pQPBuf, |
| 110 | OMX_INT blockIndex, |
| 111 | OMX_INT intraDCVLC, |
| 112 | OMX_INT ACPredFlag, |
| 113 | OMX_INT shortVideoHeader |
| 114 | ) |
| 115 | { |
| 116 | OMX_S16 tempBuf1[79], tempBuf2[79]; |
| 117 | OMX_S16 *pTempBuf1, *pTempBuf2; |
| 118 | OMX_INT predDir, predACDir; |
| 119 | OMX_INT predQP; |
| 120 | OMXVCM4P2VideoComponent videoComp; |
| 121 | OMXResult errorCode; |
| 122 | |
| 123 | |
| 124 | /* Aligning the local buffers */ |
| 125 | pTempBuf1 = armAlignTo16Bytes(tempBuf1); |
| 126 | pTempBuf2 = armAlignTo16Bytes(tempBuf2); |
| 127 | |
| 128 | /* Setting the AC prediction direction and prediction direction */ |
| 129 | armVCM4P2_SetPredDir( |
| 130 | blockIndex, |
| 131 | pCoefBufRow, |
| 132 | pCoefBufCol, |
| 133 | &predDir, |
| 134 | &predQP, |
| 135 | pQPBuf); |
| 136 | |
| 137 | predACDir = predDir; |
| 138 | |
| 139 | |
| 140 | if (ACPredFlag == 0) |
| 141 | { |
| 142 | predACDir = OMX_VC_NONE; |
| 143 | } |
| 144 | |
| 145 | /* Setting the videoComp */ |
| 146 | if (blockIndex <= 3) |
| 147 | { |
| 148 | videoComp = OMX_VC_LUMINANCE; |
| 149 | } |
| 150 | else |
| 151 | { |
| 152 | videoComp = OMX_VC_CHROMINANCE; |
| 153 | } |
| 154 | |
| 155 | |
| 156 | /* VLD and zigzag */ |
| 157 | if (intraDCVLC == 1) |
| 158 | { |
| 159 | errorCode = omxVCM4P2_DecodeVLCZigzag_IntraDCVLC( |
| 160 | ppBitStream, |
| 161 | pBitOffset, |
| 162 | pTempBuf1, |
| 163 | predACDir, |
| 164 | shortVideoHeader, |
| 165 | videoComp); |
| 166 | armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); |
| 167 | } |
| 168 | else |
| 169 | { |
| 170 | errorCode = omxVCM4P2_DecodeVLCZigzag_IntraACVLC( |
| 171 | ppBitStream, |
| 172 | pBitOffset, |
| 173 | pTempBuf1, |
| 174 | predACDir, |
| 175 | shortVideoHeader); |
| 176 | armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); |
| 177 | } |
| 178 | |
| 179 | /* AC DC prediction */ |
| 180 | errorCode = omxVCM4P2_PredictReconCoefIntra( |
| 181 | pTempBuf1, |
| 182 | pCoefBufRow, |
| 183 | pCoefBufCol, |
| 184 | curQP, |
| 185 | predQP, |
| 186 | predDir, |
| 187 | ACPredFlag, |
| 188 | videoComp); |
| 189 | armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); |
| 190 | |
| 191 | /* Dequantization */ |
| 192 | errorCode = omxVCM4P2_QuantInvIntra_I( |
| 193 | pTempBuf1, |
| 194 | curQP, |
| 195 | videoComp, |
| 196 | shortVideoHeader); |
| 197 | armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); |
| 198 | |
| 199 | /* Inverse transform */ |
| 200 | errorCode = omxVCM4P2_IDCT8x8blk (pTempBuf1, pTempBuf2); |
| 201 | armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); |
| 202 | |
| 203 | /* Placing the linear array into the destination plane and clipping |
| 204 | it to 0 to 255 */ |
| 205 | |
| 206 | armVCM4P2_Clip8(pTempBuf2,pDst,step); |
| 207 | |
| 208 | |
| 209 | return OMX_Sts_NoErr; |
| 210 | } |
| 211 | |
| 212 | /* End of file */ |
| 213 | |
| 214 | |