1/**
2 *
3 * File Name:  omxVCM4P2_DecodeBlockCoef_Inter.c
4 * OpenMAX DL: v1.0.2
5 * Revision:   9641
6 * Date:       Thursday, February 7, 2008
7 *
8 * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
9 *
10 *
11 *
12 * Description:
13 * Contains modules for inter reconstruction
14 *
15 */
16
17
18#include "omxtypes.h"
19#include "armOMX.h"
20#include "omxVC.h"
21
22#include "armCOMM.h"
23
24
25/**
26 * Function: omxVCM4P2_DecodeBlockCoef_Inter
27 *
28 * Description:
29 * Decodes the INTER block coefficients. Inverse quantization, inversely zigzag
30 * positioning and IDCT, with appropriate clipping on each step, are performed
31 * on the coefficients. The results (residuals) are placed in a contiguous array
32 * of 64 elements. For INTER block, the output buffer holds the residuals for
33 * further reconstruction.
34 *
35 * Remarks:
36 *
37 * Parameters:
38 * [in]	ppBitStream		pointer to the pointer to the current byte in
39 *								the bit stream buffer. There is no boundary
40 *								check for the bit stream buffer.
41 * [in]	pBitOffset		pointer to the bit position in the byte pointed
42 *								to by *ppBitStream. *pBitOffset is valid within
43 *								[0-7]
44 * [in]	QP				quantization parameter
45 * [in] shortVideoHeader    a flag indicating presence of short_video_header;
46 *                           shortVideoHeader==1 indicates using quantization method defined in short
47 *                           video header mode, and shortVideoHeader==0 indicates normail quantization method.
48 * [out] ppBitStream 	*ppBitStream is updated after the block is decoded, so that it points to the
49 *                      current byte in the bit stream buffer.
50 * [out] pBitOffset		*pBitOffset is updated so that it points to the current bit position in the
51 *                      byte pointed by *ppBitStream
52 * [out] pDst			pointer to the decoded residual buffer (a contiguous array of 64 elements of
53 *                      OMX_S16 data type). Must be 16-byte aligned.
54 *
55 * Return Value:
56 * OMX_Sts_NoErr - no error
57 * OMX_Sts_BadArgErr - bad arguments
58 *   - At least one of the following pointers is Null: ppBitStream, *ppBitStream, pBitOffset , pDst
59 *   - At least one of the below case:
60 *   - *pBitOffset exceeds [0,7], QP <= 0;
61 *	 - pDst not 16-byte aligned
62 * OMX_Sts_Err - status error
63 *
64 */
65OMXResult omxVCM4P2_DecodeBlockCoef_Inter(
66     const OMX_U8 ** ppBitStream,
67     OMX_INT * pBitOffset,
68     OMX_S16 * pDst,
69     OMX_INT QP,
70     OMX_INT shortVideoHeader
71)
72{
73    /* 64 elements are needed but to align it to 16 bytes need
74    15 more elements of padding */
75    OMX_S16 tempBuf[79];
76    OMX_S16 *pTempBuf1;
77    OMXResult errorCode;
78    /* Aligning the local buffers */
79    pTempBuf1 = armAlignTo16Bytes(tempBuf);
80
81
82    /* VLD and zigzag */
83    errorCode = omxVCM4P2_DecodeVLCZigzag_Inter(ppBitStream, pBitOffset,
84                                        pTempBuf1,shortVideoHeader);
85    armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode);
86
87    /* Dequantization */
88    errorCode = omxVCM4P2_QuantInvInter_I(
89     pTempBuf1,
90     QP);
91    armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode);
92
93    /* Inverse transform */
94    errorCode = omxVCM4P2_IDCT8x8blk(pTempBuf1, pDst);
95    armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode);
96
97    return OMX_Sts_NoErr;
98}
99
100/* End of file */
101
102
103