| /* |
| * 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: omxVCM4P10_DecodeCoeffsToPairCAVLC.c |
| * OpenMAX DL: v1.0.2 |
| * Revision: 9641 |
| * Date: Thursday, February 7, 2008 |
| * |
| * |
| * |
| * |
| * H.264 decode coefficients module |
| * |
| */ |
| |
| #include "omxtypes.h" |
| #include "armOMX.h" |
| #include "omxVC.h" |
| #include "armCOMM.h" |
| #include "armVC.h" |
| |
| /** |
| * Function: omxVCM4P10_DecodeCoeffsToPairCAVLC (6.3.4.1.2) |
| * |
| * Description: |
| * Performs CAVLC decoding and inverse zigzag scan for 4x4 block of |
| * Intra16x16DCLevel, Intra16x16ACLevel, LumaLevel, and ChromaACLevel. Inverse |
| * field scan is not supported. The decoded coefficients in the packed |
| * position-coefficient buffer are stored in reverse zig-zag order, i.e., the |
| * first buffer element contains the last non-zero postion-coefficient pair of |
| * the block. Within each position-coefficient pair, the position entry |
| * indicates the raster-scan position of the coefficient, while the |
| * coefficient entry contains the coefficient value. |
| * |
| * Input Arguments: |
| * |
| * ppBitStream -Double pointer to current byte in bit stream buffer |
| * pOffset - Pointer to current bit position in the byte pointed to by |
| * *ppBitStream; valid in the range [0,7]. |
| * sMaxNumCoeff - Maximum the number of non-zero coefficients in current |
| * block |
| * sVLCSelect - VLC table selector, obtained from the number of non-zero |
| * coefficients contained in the above and left 4x4 blocks. It is |
| * equivalent to the variable nC described in H.264 standard table |
| * 9 5, except its value can t be less than zero. |
| * |
| * Output Arguments: |
| * |
| * ppBitStream - *ppBitStream is updated after each block is decoded. |
| * Buffer position (*ppPosCoefBuf) is updated upon return, unless |
| * there are only zero coefficients in the currently decoded block. |
| * In this case the caller is expected to bypass the |
| * transform/dequantization of the empty blocks. |
| * pOffset - *pOffset is updated after each block is decoded |
| * pNumCoeff - Pointer to the number of nonzero coefficients in this block |
| * ppPosCoefBuf - Double pointer to destination residual |
| * coefficient-position pair buffer |
| * |
| * Return Value: |
| * OMX_Sts_NoErr, if the function runs without error. |
| * |
| * OMX_Sts_BadArgErr - bad arguments: if one of the following cases occurs: |
| * - ppBitStream or pOffset is NULL. |
| * - ppPosCoefBuf or pNumCoeff is NULL. |
| * - sMaxNumCoeff is not equal to either 15 or 16. |
| * - sVLCSelect is less than 0. |
| * |
| * OMX_Sts_Err - if one of the following is true: |
| * - an illegal code is encountered in the bitstream |
| * |
| */ |
| |
| OMXResult omxVCM4P10_DecodeCoeffsToPairCAVLC( |
| const OMX_U8** ppBitStream, |
| OMX_S32* pOffset, |
| OMX_U8* pNumCoeff, |
| OMX_U8**ppPosCoefbuf, |
| OMX_INT sVLCSelect, |
| OMX_INT sMaxNumCoeff |
| ) |
| { |
| int nTable; |
| |
| armRetArgErrIf(ppBitStream==NULL , OMX_Sts_BadArgErr); |
| armRetArgErrIf(*ppBitStream==NULL , OMX_Sts_BadArgErr); |
| armRetArgErrIf(pOffset==NULL , OMX_Sts_BadArgErr); |
| armRetArgErrIf(*pOffset<0 , OMX_Sts_BadArgErr); |
| armRetArgErrIf(*pOffset>7 , OMX_Sts_BadArgErr); |
| armRetArgErrIf(pNumCoeff==NULL , OMX_Sts_BadArgErr); |
| armRetArgErrIf(ppPosCoefbuf==NULL , OMX_Sts_BadArgErr); |
| armRetArgErrIf(*ppPosCoefbuf==NULL , OMX_Sts_BadArgErr); |
| armRetArgErrIf(sVLCSelect<0 , OMX_Sts_BadArgErr); |
| armRetArgErrIf(sMaxNumCoeff<15 , OMX_Sts_BadArgErr); |
| armRetArgErrIf(sMaxNumCoeff>16 , OMX_Sts_BadArgErr); |
| |
| /* Find VLC table number */ |
| if (sVLCSelect<2) |
| { |
| nTable = 0; |
| } |
| else if (sVLCSelect<4) |
| { |
| nTable = 1; |
| } |
| else if (sVLCSelect<8) |
| { |
| nTable = 2; |
| } |
| else /* sVLCSelect >= 8 */ |
| { |
| nTable = 3; |
| } |
| |
| return armVCM4P10_DecodeCoeffsToPair(ppBitStream, pOffset, pNumCoeff, |
| ppPosCoefbuf, nTable, sMaxNumCoeff); |
| } |