omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c revision 78e52bfac041d71ce53b5b13c2abf78af742b09d
178e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar/* 278e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * Copyright (C) 2007-2008 ARM Limited 378e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * 478e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * Licensed under the Apache License, Version 2.0 (the "License"); 578e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * you may not use this file except in compliance with the License. 678e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * You may obtain a copy of the License at 778e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * 878e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * http://www.apache.org/licenses/LICENSE-2.0 978e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * 1078e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * Unless required by applicable law or agreed to in writing, software 1178e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * distributed under the License is distributed on an "AS IS" BASIS, 1278e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1378e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * See the License for the specific language governing permissions and 1478e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * limitations under the License. 1578e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar * 1678e52bfac041d71ce53b5b13c2abf78af742b09dLajos Molnar */ 170c1bc742181ded4930842b46e9507372f0b1b963James Dong/** 180c1bc742181ded4930842b46e9507372f0b1b963James Dong * 190c1bc742181ded4930842b46e9507372f0b1b963James Dong * File Name: omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c 200c1bc742181ded4930842b46e9507372f0b1b963James Dong * OpenMAX DL: v1.0.2 210c1bc742181ded4930842b46e9507372f0b1b963James Dong * Revision: 9641 220c1bc742181ded4930842b46e9507372f0b1b963James Dong * Date: Thursday, February 7, 2008 230c1bc742181ded4930842b46e9507372f0b1b963James Dong * 240c1bc742181ded4930842b46e9507372f0b1b963James Dong * 250c1bc742181ded4930842b46e9507372f0b1b963James Dong * 260c1bc742181ded4930842b46e9507372f0b1b963James Dong * 270c1bc742181ded4930842b46e9507372f0b1b963James Dong * Description: 280c1bc742181ded4930842b46e9507372f0b1b963James Dong * Contains modules for zigzag scanning and VLC decoding 290c1bc742181ded4930842b46e9507372f0b1b963James Dong * for intra block. 300c1bc742181ded4930842b46e9507372f0b1b963James Dong * 310c1bc742181ded4930842b46e9507372f0b1b963James Dong */ 320c1bc742181ded4930842b46e9507372f0b1b963James Dong 330c1bc742181ded4930842b46e9507372f0b1b963James Dong#include "omxtypes.h" 340c1bc742181ded4930842b46e9507372f0b1b963James Dong#include "armOMX.h" 350c1bc742181ded4930842b46e9507372f0b1b963James Dong#include "omxVC.h" 360c1bc742181ded4930842b46e9507372f0b1b963James Dong 370c1bc742181ded4930842b46e9507372f0b1b963James Dong#include "armVC.h" 380c1bc742181ded4930842b46e9507372f0b1b963James Dong#include "armCOMM.h" 390c1bc742181ded4930842b46e9507372f0b1b963James Dong 400c1bc742181ded4930842b46e9507372f0b1b963James Dong 410c1bc742181ded4930842b46e9507372f0b1b963James Dong 420c1bc742181ded4930842b46e9507372f0b1b963James Dong/** 430c1bc742181ded4930842b46e9507372f0b1b963James Dong * Function: omxVCM4P2_DecodeVLCZigzag_IntraACVLC (6.2.5.2.2) 440c1bc742181ded4930842b46e9507372f0b1b963James Dong * 450c1bc742181ded4930842b46e9507372f0b1b963James Dong * Description: 460c1bc742181ded4930842b46e9507372f0b1b963James Dong * Performs VLC decoding and inverse zigzag scan of AC and DC coefficients 470c1bc742181ded4930842b46e9507372f0b1b963James Dong * for one intra block. Two versions of the function (DCVLC and ACVLC) are 480c1bc742181ded4930842b46e9507372f0b1b963James Dong * provided in order to support the two different methods of processing DC 490c1bc742181ded4930842b46e9507372f0b1b963James Dong * coefficients, as described in [ISO14496-2], subclause 7.4.1.4, Intra DC 500c1bc742181ded4930842b46e9507372f0b1b963James Dong * Coefficient Decoding for the Case of Switched VLC Encoding. 510c1bc742181ded4930842b46e9507372f0b1b963James Dong * 520c1bc742181ded4930842b46e9507372f0b1b963James Dong * Input Arguments: 530c1bc742181ded4930842b46e9507372f0b1b963James Dong * 540c1bc742181ded4930842b46e9507372f0b1b963James Dong * ppBitStream - pointer to the pointer to the current byte in the 550c1bc742181ded4930842b46e9507372f0b1b963James Dong * bitstream buffer 560c1bc742181ded4930842b46e9507372f0b1b963James Dong * pBitOffset - pointer to the bit position in the current byte referenced 570c1bc742181ded4930842b46e9507372f0b1b963James Dong * by *ppBitStream. The parameter *pBitOffset is valid in the 580c1bc742181ded4930842b46e9507372f0b1b963James Dong * range [0-7]. Bit Position in one byte: |Most Least| *pBitOffset 590c1bc742181ded4930842b46e9507372f0b1b963James Dong * |0 1 2 3 4 5 6 7| 600c1bc742181ded4930842b46e9507372f0b1b963James Dong * predDir - AC prediction direction; used to select the zigzag scan 610c1bc742181ded4930842b46e9507372f0b1b963James Dong * pattern; takes one of the following values: OMX_VC_NONE - AC 620c1bc742181ded4930842b46e9507372f0b1b963James Dong * prediction not used; performs classical zigzag scan. 630c1bc742181ded4930842b46e9507372f0b1b963James Dong * OMX_VC_HORIZONTAL - Horizontal prediction; performs 640c1bc742181ded4930842b46e9507372f0b1b963James Dong * alternate-vertical zigzag scan; OMX_VC_VERTICAL - Vertical 650c1bc742181ded4930842b46e9507372f0b1b963James Dong * prediction; performs alternate-horizontal zigzag scan. 660c1bc742181ded4930842b46e9507372f0b1b963James Dong * shortVideoHeader - binary flag indicating presence of 670c1bc742181ded4930842b46e9507372f0b1b963James Dong * short_video_header; escape modes 0-3 are used if 680c1bc742181ded4930842b46e9507372f0b1b963James Dong * shortVideoHeader==0, and escape mode 4 is used when 690c1bc742181ded4930842b46e9507372f0b1b963James Dong * shortVideoHeader==1. 700c1bc742181ded4930842b46e9507372f0b1b963James Dong * videoComp - video component type (luminance or chrominance) of the 710c1bc742181ded4930842b46e9507372f0b1b963James Dong * current block 720c1bc742181ded4930842b46e9507372f0b1b963James Dong * 730c1bc742181ded4930842b46e9507372f0b1b963James Dong * Output Arguments: 740c1bc742181ded4930842b46e9507372f0b1b963James Dong * 750c1bc742181ded4930842b46e9507372f0b1b963James Dong * ppBitStream - *ppBitStream is updated after the block is decoded such 760c1bc742181ded4930842b46e9507372f0b1b963James Dong * that it points to the current byte in the bit stream buffer 770c1bc742181ded4930842b46e9507372f0b1b963James Dong * pBitOffset - *pBitOffset is updated such that it points to the current 780c1bc742181ded4930842b46e9507372f0b1b963James Dong * bit position in the byte pointed by *ppBitStream 790c1bc742181ded4930842b46e9507372f0b1b963James Dong * pDst - pointer to the coefficient buffer of current block; must be 800c1bc742181ded4930842b46e9507372f0b1b963James Dong * 4-byte aligned. 810c1bc742181ded4930842b46e9507372f0b1b963James Dong * 820c1bc742181ded4930842b46e9507372f0b1b963James Dong * Return Value: 830c1bc742181ded4930842b46e9507372f0b1b963James Dong * 840c1bc742181ded4930842b46e9507372f0b1b963James Dong * OMX_Sts_NoErr - no error 850c1bc742181ded4930842b46e9507372f0b1b963James Dong * OMX_Sts_BadArgErr - bad arguments At least one of the following 860c1bc742181ded4930842b46e9507372f0b1b963James Dong * pointers is NULL: ppBitStream, *ppBitStream, pBitOffset, pDst, 870c1bc742181ded4930842b46e9507372f0b1b963James Dong * or At least one of the following conditions is true: 880c1bc742181ded4930842b46e9507372f0b1b963James Dong * *pBitOffset exceeds [0,7], preDir exceeds [0,2], or pDst is 890c1bc742181ded4930842b46e9507372f0b1b963James Dong * not 4-byte aligned 900c1bc742181ded4930842b46e9507372f0b1b963James Dong * OMX_Sts_Err In DecodeVLCZigzag_IntraDCVLC, dc_size > 12 At least one of 910c1bc742181ded4930842b46e9507372f0b1b963James Dong * mark bits equals zero Illegal stream encountered; code cannot 920c1bc742181ded4930842b46e9507372f0b1b963James Dong * be located in VLC table Forbidden code encountered in the VLC 930c1bc742181ded4930842b46e9507372f0b1b963James Dong * FLC table The number of coefficients is greater than 64 940c1bc742181ded4930842b46e9507372f0b1b963James Dong * 950c1bc742181ded4930842b46e9507372f0b1b963James Dong */ 960c1bc742181ded4930842b46e9507372f0b1b963James Dong 970c1bc742181ded4930842b46e9507372f0b1b963James Dong 980c1bc742181ded4930842b46e9507372f0b1b963James DongOMXResult omxVCM4P2_DecodeVLCZigzag_IntraACVLC( 990c1bc742181ded4930842b46e9507372f0b1b963James Dong const OMX_U8 ** ppBitStream, 1000c1bc742181ded4930842b46e9507372f0b1b963James Dong OMX_INT * pBitOffset, 1010c1bc742181ded4930842b46e9507372f0b1b963James Dong OMX_S16 * pDst, 1020c1bc742181ded4930842b46e9507372f0b1b963James Dong OMX_U8 predDir, 1030c1bc742181ded4930842b46e9507372f0b1b963James Dong OMX_INT shortVideoHeader 1040c1bc742181ded4930842b46e9507372f0b1b963James Dong) 1050c1bc742181ded4930842b46e9507372f0b1b963James Dong{ 1060c1bc742181ded4930842b46e9507372f0b1b963James Dong OMX_U8 start = 0; 1070c1bc742181ded4930842b46e9507372f0b1b963James Dong 1080c1bc742181ded4930842b46e9507372f0b1b963James Dong return armVCM4P2_DecodeVLCZigzag_Intra( 1090c1bc742181ded4930842b46e9507372f0b1b963James Dong ppBitStream, 1100c1bc742181ded4930842b46e9507372f0b1b963James Dong pBitOffset, 1110c1bc742181ded4930842b46e9507372f0b1b963James Dong pDst, 1120c1bc742181ded4930842b46e9507372f0b1b963James Dong predDir, 1130c1bc742181ded4930842b46e9507372f0b1b963James Dong shortVideoHeader, 1140c1bc742181ded4930842b46e9507372f0b1b963James Dong start); 1150c1bc742181ded4930842b46e9507372f0b1b963James Dong} 1160c1bc742181ded4930842b46e9507372f0b1b963James Dong 1170c1bc742181ded4930842b46e9507372f0b1b963James Dong/* End of file */ 1180c1bc742181ded4930842b46e9507372f0b1b963James Dong 119