| /* |
| * 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_EncodeVLCZigzag_IntraACVLC.c |
| * OpenMAX DL: v1.0.2 |
| * Revision: 9641 |
| * Date: Thursday, February 7, 2008 |
| * |
| * |
| * |
| * |
| * Description: |
| * Contains modules for zigzag scanning and VLC encoding |
| * for intra block. |
| * |
| */ |
| |
| #include "omxtypes.h" |
| #include "armOMX.h" |
| #include "omxVC.h" |
| |
| #include "armVC.h" |
| |
| |
| /** |
| * Function: omxVCM4P2_EncodeVLCZigzag_IntraACVLC (6.2.4.5.2) |
| * |
| * Description: |
| * Performs zigzag scan and VLC encoding of AC and DC coefficients for one |
| * intra block. Two versions of the function (DCVLC and ACVLC) are provided |
| * in order to support the two different methods of processing DC |
| * coefficients, as described in [ISO14496-2], subclause 7.4.1.4, Intra DC |
| * Coefficient Decoding for the Case of Switched VLC Encoding. |
| * |
| * Input Arguments: |
| * |
| * ppBitStream - double pointer to the current byte in the bitstream |
| * pBitOffset - pointer to the bit position in the byte pointed by |
| * *ppBitStream. Valid within 0 to 7. |
| * pQDctBlkCoef - pointer to the quantized DCT coefficient |
| * predDir - AC prediction direction, which is used to decide the zigzag |
| * scan pattern; takes one of the following values: |
| * - OMX_VC_NONE - AC prediction not used. |
| * Performs classical zigzag scan. |
| * - OMX_VC_HORIZONTAL - Horizontal prediction. |
| * Performs alternate-vertical zigzag scan. |
| * - OMX_VC_VERTICAL - Vertical prediction. |
| * Performs alternate-horizontal zigzag scan. |
| * pattern - block pattern which is used to decide whether this block is |
| * encoded |
| * shortVideoHeader - binary flag indicating presence of |
| * short_video_header; escape modes 0-3 are used if |
| * shortVideoHeader==0, and escape mode 4 is used when |
| * shortVideoHeader==1. |
| * |
| * Output Arguments: |
| * |
| * ppBitStream - *ppBitStream is updated after the block is encoded, so |
| * that it points to the current byte in the bit stream buffer. |
| * pBitOffset - *pBitOffset is updated so that it points to the current bit |
| * position in the byte pointed by *ppBitStream. |
| * |
| * Return Value: |
| * |
| * OMX_Sts_NoErr - no error |
| * OMX_Sts_BadArgErr - Bad arguments: |
| * - At least one of the following pointers is NULL: ppBitStream, |
| * *ppBitStream, pBitOffset, pQDctBlkCoef. |
| * - *pBitOffset < 0, or *pBitOffset >7. |
| * - PredDir is not one of: OMX_VC_NONE, OMX_VC_HORIZONTAL, or |
| * OMX_VC_VERTICAL. |
| * - VideoComp is not one component of enum OMXVCM4P2VideoComponent. |
| * |
| */ |
| |
| OMXResult omxVCM4P2_EncodeVLCZigzag_IntraACVLC( |
| OMX_U8 **ppBitStream, |
| OMX_INT *pBitOffset, |
| const OMX_S16 *pQDctBlkCoef, |
| OMX_U8 predDir, |
| OMX_U8 pattern, |
| OMX_INT shortVideoHeader |
| ) |
| { |
| OMX_U8 start = 0; |
| |
| return armVCM4P2_EncodeVLCZigzag_Intra( |
| ppBitStream, |
| pBitOffset, |
| pQDctBlkCoef, |
| predDir, |
| pattern, |
| shortVideoHeader, |
| start); |
| } |
| |
| /* End of file */ |
