armVCM4P2_EncodeVLCZigzag_intra.c revision 78e52bfac041d71ce53b5b13c2abf78af742b09d 
1/*
2 * Copyright (C) 2007-2008 ARM Limited
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *
16 */
17/**
18 *
19 * File Name:  armVCM4P2_EncodeVLCZigzag_intra.c
20 * OpenMAX DL: v1.0.2
21 * Revision:   9641
22 * Date:       Thursday, February 7, 2008
23 *
24 *
25 *
26 *
27 * Description:
28 * Contains modules for zigzag scanning and VLC encoding
29 * for intra block.
30 *
31 */
32
33#include "omxtypes.h"
34#include "armOMX.h"
35#include "omxVC.h"
36
37#include "armVC.h"
38#include "armCOMM_Bitstream.h"
39#include "armCOMM.h"
40#include "armVCM4P2_Huff_Tables_VLC.h"
41#include "armVCM4P2_ZigZag_Tables.h"
42
43
44
45/**
46 * Function: armVCM4P2_EncodeVLCZigzag_Intra
47 *
48 * Description:
49 * Performs zigzag scanning and VLC encoding for one intra block.
50 *
51 * Remarks:
52 *
53 * Parameters:
54 * [in] ppBitStream     pointer to the pointer to the current byte in
55 *                              the bit stream
56 * [in] pBitOffset      pointer to the bit position in the byte pointed
57 *                              by *ppBitStream. Valid within 0 to 7.
58 * [in] pQDctBlkCoef    pointer to the quantized DCT coefficient
59 * [in] predDir         AC prediction direction, which is used to decide
60 *                              the zigzag scan pattern. This takes one of the
61 *                              following values:
62 *                              OMX_VC_NONE          AC prediction not used.
63 *                                                      Performs classical zigzag
64 *                                                      scan.
65 *                              OMX_VC_HORIZONTAL    Horizontal prediction.
66 *                                                      Performs alternate-vertical
67 *                                                      zigzag scan.
68 *                              OMX_VC_VERTICAL      Vertical prediction.
69 *                                                      Performs alternate-horizontal
70 *                                                      zigzag scan.
71 * [in] pattern         block pattern which is used to decide whether
72 *                              this block is encoded
73 * [in] start           start indicates whether the encoding begins with 0th element
74 *                      or 1st.
75 * [out]    ppBitStream     *ppBitStream is updated after the block is encoded,
76 *                              so that it points to the current byte in the bit
77 *                              stream buffer.
78 * [out]    pBitOffset      *pBitOffset is updated so that it points to the
79 *                              current bit position in the byte pointed by
80 *                              *ppBitStream.
81 *
82 * Return Value:
83 * Standard OMXResult result. See enumeration for possible result codes.
84 *
85 */
86
87OMXResult armVCM4P2_EncodeVLCZigzag_Intra(
88     OMX_U8 **ppBitStream,
89     OMX_INT *pBitOffset,
90     const OMX_S16 *pQDctBlkCoef,
91     OMX_U8 predDir,
92     OMX_U8 pattern,
93     OMX_INT shortVideoHeader,
94     OMX_U8 start
95)
96{
97    const OMX_U8  *pZigzagTable = armVCM4P2_aClassicalZigzagScan;
98    OMXResult errorCode;
99
100    /* Argument error checks */
101    armRetArgErrIf(ppBitStream == NULL, OMX_Sts_BadArgErr);
102    armRetArgErrIf(*ppBitStream == NULL, OMX_Sts_BadArgErr);
103    armRetArgErrIf(pBitOffset == NULL, OMX_Sts_BadArgErr);
104    armRetArgErrIf(pQDctBlkCoef == NULL, OMX_Sts_BadArgErr);
105    armRetArgErrIf((*pBitOffset < 0) || (*pBitOffset >7), OMX_Sts_BadArgErr);
106    armRetArgErrIf(start > 1, OMX_Sts_BadArgErr);
107    armRetArgErrIf(predDir > 2, OMX_Sts_BadArgErr);
108
109    if (pattern)
110    {
111        switch (predDir)
112        {
113            case OMX_VC_NONE:
114            {
115                pZigzagTable = armVCM4P2_aClassicalZigzagScan;
116                break;
117            }
118
119            case OMX_VC_HORIZONTAL:
120            {
121                pZigzagTable = armVCM4P2_aVerticalZigzagScan;
122                break;
123            }
124
125            case OMX_VC_VERTICAL:
126            {
127                pZigzagTable = armVCM4P2_aHorizontalZigzagScan;
128                break;
129            }
130        }
131
132        errorCode = armVCM4P2_PutVLCBits (
133              ppBitStream,
134              pBitOffset,
135              pQDctBlkCoef,
136              shortVideoHeader,
137              start,
138              14,
139              20,
140              9,
141              6,
142              armVCM4P2_IntraL0RunIdx,
143              armVCM4P2_IntraVlcL0,
144			  armVCM4P2_IntraL1RunIdx,
145              armVCM4P2_IntraVlcL1,
146              armVCM4P2_IntraL0LMAX,
147              armVCM4P2_IntraL1LMAX,
148              armVCM4P2_IntraL0RMAX,
149              armVCM4P2_IntraL1RMAX,
150              pZigzagTable
151        );
152        armRetDataErrIf((errorCode != OMX_Sts_NoErr), errorCode);
153
154    } /* Pattern check ends*/
155
156    return (OMX_Sts_NoErr);
157
158}
159
160/* End of file */
161