1 /* ---------------------------------------------------------------- 2 * 3 * 4 * File Name: armVCM4P10_UnpackBlock2x2.c 5 * OpenMAX DL: v1.0.2 6 * Revision: 9641 7 * Date: Thursday, February 7, 2008 8 * 9 * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved. 10 * 11 * 12 * 13 * H.264 inverse quantize and transform helper module 14 * 15 */ 16 17 #include "omxtypes.h" 18 #include "armOMX.h" 19 #include "omxVC.h" 20 21 #include "armVC.h" 22 23 /* 24 * Description 25 * Unpack a 2x2 block of coefficient-residual pair values 26 * 27 * Parameters: 28 * [in] ppSrc Double pointer to residual coefficient-position pair 29 * buffer output by CALVC decoding 30 * [out] ppSrc *ppSrc is updated to the start of next non empty block 31 * [out] pDst Pointer to unpacked 4x4 block 32 */ 33 34 void armVCM4P10_UnpackBlock2x2( 35 const OMX_U8 **ppSrc, 36 OMX_S16* pDst 37 ) 38 { 39 const OMX_U8 *pSrc = *ppSrc; 40 int i; 41 int Flag, Value; 42 43 for (i=0; i<4; i++) 44 { 45 pDst[i] = 0; 46 } 47 48 do 49 { 50 Flag = *pSrc++; 51 if (Flag & 0x10) 52 { 53 /* 16 bit */ 54 Value = *pSrc++; 55 Value = Value | ((*pSrc++)<<8); 56 if (Value & 0x8000) 57 { 58 Value -= 0x10000; 59 } 60 } 61 else 62 { 63 /* 8 bit */ 64 Value = *pSrc++; 65 if (Value & 0x80) 66 { 67 Value -= 0x100; 68 } 69 } 70 i = Flag & 15; 71 pDst[i] = (OMX_S16)Value; 72 } 73 while ((Flag & 0x20)==0); 74 75 *ppSrc = pSrc; 76 } 77 78 /* End of file */ 79
