omxVCM4P2_EncodeVLCZigzag_Inter.c revision 0c1bc742181ded4930842b46e9507372f0b1b963
1/**
2 *
3 * File Name:  omxVCM4P2_EncodeVLCZigzag_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 zigzag scanning and VLC encoding
14 * for inter block.
15 *
16 */
17
18#include "omxtypes.h"
19#include "armOMX.h"
20#include "omxVC.h"
21
22#include "armVC.h"
23#include "armCOMM_Bitstream.h"
24#include "armCOMM.h"
25#include "armVCM4P2_Huff_Tables_VLC.h"
26#include "armVCM4P2_ZigZag_Tables.h"
27
28
29
30/**
31 * Function:  omxVCM4P2_EncodeVLCZigzag_Inter   (6.2.4.5.3)
32 *
33 * Description:
34 * Performs classical zigzag scanning and VLC encoding for one inter block.
35 *
36 * Input Arguments:
37 *
38 *   ppBitStream - pointer to the pointer to the current byte in the bit
39 *            stream
40 *   pBitOffset - pointer to the bit position in the byte pointed by
41 *            *ppBitStream. Valid within 0 to 7
42 *   pQDctBlkCoef - pointer to the quantized DCT coefficient
43 *   pattern - block pattern which is used to decide whether this block is
44 *            encoded
45 *   shortVideoHeader - binary flag indicating presence of
46 *            short_video_header; escape modes 0-3 are used if
47 *            shortVideoHeader==0, and escape mode 4 is used when
48 *            shortVideoHeader==1.
49 *
50 * Output Arguments:
51 *
52 *   ppBitStream - *ppBitStream is updated after the block is encoded so that
53 *            it points to the current byte in the bit stream buffer.
54 *   pBitOffset - *pBitOffset is updated so that it points to the current bit
55 *            position in the byte pointed by *ppBitStream.
56 *
57 * Return Value:
58 *
59 *    OMX_Sts_NoErr - no error
60 *    OMX_Sts_BadArgErr - Bad arguments
61 *    -    At least one of the pointers: is NULL: ppBitStream, *ppBitStream,
62 *              pBitOffset, pQDctBlkCoef
63 *    -   *pBitOffset < 0, or *pBitOffset >7.
64 *
65 */
66OMXResult omxVCM4P2_EncodeVLCZigzag_Inter(
67     OMX_U8 **ppBitStream,
68     OMX_INT * pBitOffset,
69     const OMX_S16 *pQDctBlkCoef,
70     OMX_U8 pattern,
71	 OMX_INT shortVideoHeader
72)
73{
74    OMX_U8 start = 0;
75    const OMX_U8  *pZigzagTable = armVCM4P2_aClassicalZigzagScan;
76
77    /* Argument error checks */
78    armRetArgErrIf(ppBitStream == NULL, OMX_Sts_BadArgErr);
79    armRetArgErrIf(*ppBitStream == NULL, OMX_Sts_BadArgErr);
80    armRetArgErrIf(pBitOffset == NULL, OMX_Sts_BadArgErr);
81    armRetArgErrIf(pQDctBlkCoef == NULL, OMX_Sts_BadArgErr);
82    armRetArgErrIf((*pBitOffset < 0) || (*pBitOffset >7), OMX_Sts_BadArgErr);
83
84    if (pattern)
85    {
86        armVCM4P2_PutVLCBits (
87              ppBitStream,
88              pBitOffset,
89              pQDctBlkCoef,
90              shortVideoHeader,
91              start,
92              26,
93              40,
94              10,
95              1,
96              armVCM4P2_InterL0RunIdx,
97              armVCM4P2_InterVlcL0,
98			  armVCM4P2_InterL1RunIdx,
99              armVCM4P2_InterVlcL1,
100              armVCM4P2_InterL0LMAX,
101              armVCM4P2_InterL1LMAX,
102              armVCM4P2_InterL0RMAX,
103              armVCM4P2_InterL1RMAX,
104              pZigzagTable
105        );
106    } /* Pattern check ends*/
107
108    return OMX_Sts_NoErr;
109
110}
111
112/* End of file */
113