clip2.c
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上传日期:2007-06-06
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- /* ***** BEGIN LICENSE BLOCK *****
- * Version: RCSL 1.0/RPSL 1.0
- *
- * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved.
- *
- * The contents of this file, and the files included with this file, are
- * subject to the current version of the RealNetworks Public Source License
- * Version 1.0 (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the RealNetworks Community Source License Version 1.0
- * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl,
- * in which case the RCSL will apply. You may also obtain the license terms
- * directly from RealNetworks. You may not use this file except in
- * compliance with the RPSL or, if you have a valid RCSL with RealNetworks
- * applicable to this file, the RCSL. Please see the applicable RPSL or
- * RCSL for the rights, obligations and limitations governing use of the
- * contents of the file.
- *
- * This file is part of the Helix DNA Technology. RealNetworks is the
- * developer of the Original Code and owns the copyrights in the portions
- * it created.
- *
- * This file, and the files included with this file, is distributed and made
- * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
- * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- *
- * Technology Compatibility Kit Test Suite(s) Location:
- * http://www.helixcommunity.org/content/tck
- *
- * Contributor(s):
- *
- * ***** END LICENSE BLOCK ***** */
- //#include <math.h>
- #include "dllindex.h"
- #include "h261defs.h"
- #include "h261func.h"
- #include "clip.h"
- #define FRACBITS 6 /* Fractional bits in IDCT computation */
- #define PIXEL_MIN 0
- #define PIXEL_MAX 255
- #define CLIPMARGIN 300
- #define CLIPMIN (PIXEL_MIN - CLIPMARGIN)
- #define CLIPMAX (PIXEL_MAX + CLIPMARGIN)
- extern PIXEL clip[(CLIPMAX-CLIPMIN+1)];
- extern void idct2sum_clip(PIXEL x[], int xdim, S32 idct_out[8][4], int idct_class)
- {
- int i, temp;
- #ifdef LITTLE_ENDIAN
- int hi_clip0, hi_clip1, hi_clip2, hi_clip3;
- int lo_clip0, lo_clip1, lo_clip2, lo_clip3;
- switch (idct_class)
- // DC only case
- {
- case DC_ONLY:
- {
- temp = idct_out[0][0];
- lo_clip0 = -CLIPMIN + ((temp << 16) >> (FRACBITS + 16));
- hi_clip0 = -CLIPMIN + (temp >> (FRACBITS + 16));
- for (i = 0; i < 8; i++)
- {
- x[i*xdim] = clip[x[i*xdim]+lo_clip0];
- x[i*xdim+1] = clip[x[i*xdim+1]+hi_clip0];
- x[i*xdim+2] = clip[x[i*xdim+2]+lo_clip0];
- x[i*xdim+3] = clip[x[i*xdim+3]+hi_clip0];
- x[i*xdim+7] = clip[x[i*xdim+7]+lo_clip0];
- x[i*xdim+6] = clip[x[i*xdim+6]+hi_clip0];
- x[i*xdim+5] = clip[x[i*xdim+5]+lo_clip0];
- x[i*xdim+4] = clip[x[i*xdim+4]+hi_clip0];
- }
- }
- break;
- // DC + 1 horizontal AC case
- case DC_AC_H:
- {
- temp = idct_out[0][0];
- lo_clip0 = -CLIPMIN + ((temp << 16) >> (FRACBITS + 16));
- hi_clip0 = -CLIPMIN + (temp >> (FRACBITS + 16));
- temp = idct_out[0][1];
- lo_clip1 = -CLIPMIN + ((temp << 16) >> (FRACBITS + 16));
- hi_clip1 = -CLIPMIN + (temp >> (FRACBITS + 16));
- temp = idct_out[0][2];
- lo_clip2 = -CLIPMIN + ((temp << 16) >> (FRACBITS + 16));
- hi_clip2 = -CLIPMIN + (temp >> (FRACBITS + 16));
- temp = idct_out[0][3];
- lo_clip3 = -CLIPMIN + ((temp << 16) >> (FRACBITS + 16));
- hi_clip3 = -CLIPMIN + (temp >> (FRACBITS + 16));
- for (i = 0; i < 8; i++)
- {
- x[i*xdim] = clip[x[i*xdim]+lo_clip0];
- x[i*xdim+1] = clip[x[i*xdim+1]+hi_clip0];
- x[i*xdim+2] = clip[x[i*xdim+2]+lo_clip1];
- x[i*xdim+3] = clip[x[i*xdim+3]+hi_clip1];
- x[i*xdim+7] = clip[x[i*xdim+7]+lo_clip2];
- x[i*xdim+6] = clip[x[i*xdim+6]+hi_clip2];
- x[i*xdim+5] = clip[x[i*xdim+5]+lo_clip3];
- x[i*xdim+4] = clip[x[i*xdim+4]+hi_clip3];
- }
- }
- break;
-
- case GENERAL:
- {
- for (i = 0; i < 8; i++)
- {
- temp = idct_out[i][0];
- x[i*xdim] = clip[x[i*xdim] -CLIPMIN + ((temp << 16) >> (FRACBITS + 16))];
- x[i*xdim+1] = clip[x[i*xdim+1] -CLIPMIN + (temp >> (FRACBITS + 16))];
- temp = idct_out[i][1];
- x[i*xdim+2] = clip[x[i*xdim+2] -CLIPMIN + ((temp << 16) >> (FRACBITS + 16))];
- x[i*xdim+3] = clip[x[i*xdim+3] -CLIPMIN + (temp >> (FRACBITS + 16))];
- temp = idct_out[i][2];
- x[i*xdim+7] = clip[x[i*xdim+7] -CLIPMIN + ((temp << 16) >> (FRACBITS + 16))];
- x[i*xdim+6] = clip[x[i*xdim+6] -CLIPMIN + (temp >> (FRACBITS + 16))];
- temp = idct_out[i][3];
- x[i*xdim+5] = clip[x[i*xdim+5] -CLIPMIN + ((temp << 16) >> (FRACBITS + 16))];
- x[i*xdim+4] = clip[x[i*xdim+4] -CLIPMIN + (temp >> (FRACBITS + 16))];
- }
- }
- break;
-
- default:
- break;
- }
- #else
- for (i = 0; i < 8; i++)
- {
- int j;
- // Notice the funky casts of idct_out, which needs to be treated
- // as an S16 [8][8].
- for (j = 0; j < 4; j++) {
- temp = ((S16 (*)[8]) idct_out)[i][j] >> FRACBITS;
- x[i*xdim+j] = clip[x[i*xdim+j] -CLIPMIN + temp];
- temp = ((S16 (*)[8]) idct_out)[i][j+4] >> FRACBITS;
- x[i*xdim+7-j] = clip[x[i*xdim+7-j] -CLIPMIN + temp];
- }
- }
- #endif
- }