/* * 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_DecodeBlockCoef_Intra.c * OpenMAX DL: v1.0.2 * Revision: 9641 * Date: Thursday, February 7, 2008 * * * * * Description: * Contains modules for intra reconstruction * */ #include "omxtypes.h" #include "armOMX.h" #include "omxVC.h" #include "armCOMM.h" #include "armVC.h" /** * Function: omxVCM4P2_DecodeBlockCoef_Intra * * Description: * Decodes the INTRA block coefficients. Inverse quantization, inversely zigzag * positioning, and IDCT, with appropriate clipping on each step, are performed * on the coefficients. The results are then placed in the output frame/plane on * a pixel basis. For INTRA block, the output values are clipped to [0, 255] and * written to corresponding block buffer within the destination plane. * * Remarks: * * Parameters: * [in] ppBitStream pointer to the pointer to the current byte in * the bit stream buffer. There is no boundary * check for the bit stream buffer. * [in] pBitOffset pointer to the bit position in the byte pointed * to by *ppBitStream. *pBitOffset is valid within * [0-7]. * [in] step width of the destination plane * [in/out] pCoefBufRow [in] pointer to the coefficient row buffer * [out] updated coefficient rwo buffer * [in/out] pCoefBufCol [in] pointer to the coefficient column buffer * [out] updated coefficient column buffer * [in] curQP quantization parameter of the macroblock which * the current block belongs to * [in] pQpBuf Pointer to a 2-element QP array. pQpBuf[0] holds the QP of the 8x8 block left to * the current block(QPa). pQpBuf[1] holds the QP of the 8x8 block just above the * current block(QPc). * Note, in case the corresponding block is out of VOP bound, the QP value will have * no effect to the intra-prediction process. Refer to subclause "7.4.3.3 Adaptive * ac coefficient prediction" of ISO/IEC 14496-2(MPEG4 Part2) for accurate description. * [in] blockIndex block index indicating the component type and * position as defined in subclause 6.1.3.8, * Figure 6-5 of ISO/IEC 14496-2. * [in] intraDCVLC a code determined by intra_dc_vlc_thr and QP. * This allows a mechanism to switch between two VLC * for coding of Intra DC coefficients as per Table * 6-21 of ISO/IEC 14496-2. * [in] ACPredFlag a flag equal to ac_pred_flag (of luminance) indicating * if the ac coefficients of the first row or first * column are differentially coded for intra coded * macroblock. * [in] shortVideoHeader a flag indicating presence of short_video_header; * shortVideoHeader==1 selects linear intra DC mode, * and shortVideoHeader==0 selects nonlinear intra DC mode. * [out] ppBitStream *ppBitStream is updated after the block is * decoded, so that it points to the current byte * in the bit stream buffer * [out] pBitOffset *pBitOffset is updated so that it points to the * current bit position in the byte pointed by * *ppBitStream * [out] pDst pointer to the block in the destination plane. * pDst should be 16-byte aligned. * [out] pCoefBufRow pointer to the updated coefficient row buffer. * * Return Value: * OMX_Sts_NoErr - no error * OMX_Sts_BadArgErr - bad arguments * - At least one of the following pointers is NULL: ppBitStream, *ppBitStream, pBitOffset, * pCoefBufRow, pCoefBufCol, pQPBuf, pDst. * or * - At least one of the below case: *pBitOffset exceeds [0,7], curQP exceeds (1, 31), * blockIndex exceeds [0,9], step is not the multiple of 8, intraDCVLC is zero while * blockIndex greater than 5. * or * - pDst is not 16-byte aligned * OMX_Sts_Err - status error * */ OMXResult omxVCM4P2_DecodeBlockCoef_Intra( const OMX_U8 ** ppBitStream, OMX_INT *pBitOffset, OMX_U8 *pDst, OMX_INT step, OMX_S16 *pCoefBufRow, OMX_S16 *pCoefBufCol, OMX_U8 curQP, const OMX_U8 *pQPBuf, OMX_INT blockIndex, OMX_INT intraDCVLC, OMX_INT ACPredFlag, OMX_INT shortVideoHeader ) { OMX_S16 tempBuf1[79], tempBuf2[79]; OMX_S16 *pTempBuf1, *pTempBuf2; OMX_INT predDir, predACDir; OMX_INT predQP; OMXVCM4P2VideoComponent videoComp; OMXResult errorCode; /* Aligning the local buffers */ pTempBuf1 = armAlignTo16Bytes(tempBuf1); pTempBuf2 = armAlignTo16Bytes(tempBuf2); /* Setting the AC prediction direction and prediction direction */ armVCM4P2_SetPredDir( blockIndex, pCoefBufRow, pCoefBufCol, &predDir, &predQP, pQPBuf); predACDir = predDir; if (ACPredFlag == 0) { predACDir = OMX_VC_NONE; } /* Setting the videoComp */ if (blockIndex <= 3) { videoComp = OMX_VC_LUMINANCE; } else { videoComp = OMX_VC_CHROMINANCE; } /* VLD and zigzag */ if (intraDCVLC == 1) { errorCode = omxVCM4P2_DecodeVLCZigzag_IntraDCVLC( ppBitStream, pBitOffset, pTempBuf1, predACDir, shortVideoHeader, videoComp); armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); } else { errorCode = omxVCM4P2_DecodeVLCZigzag_IntraACVLC( ppBitStream, pBitOffset, pTempBuf1, predACDir, shortVideoHeader); armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); } /* AC DC prediction */ errorCode = omxVCM4P2_PredictReconCoefIntra( pTempBuf1, pCoefBufRow, pCoefBufCol, curQP, predQP, predDir, ACPredFlag, videoComp); armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); /* Dequantization */ errorCode = omxVCM4P2_QuantInvIntra_I( pTempBuf1, curQP, videoComp, shortVideoHeader); armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); /* Inverse transform */ errorCode = omxVCM4P2_IDCT8x8blk (pTempBuf1, pTempBuf2); armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode); /* Placing the linear array into the destination plane and clipping it to 0 to 255 */ armVCM4P2_Clip8(pTempBuf2,pDst,step); return OMX_Sts_NoErr; } /* End of file */