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/***************************************************************************** |
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* |
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* XVID MPEG-4 VIDEO CODEC |
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* - Forward DCT - |
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* |
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* These routines are from Independent JPEG Group's free JPEG software |
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* Copyright (C) 1991-1998, Thomas G. Lane (see the file README.IJG) |
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* |
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* This program is free software ; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation ; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY ; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program ; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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* |
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* $Id$ |
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* |
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****************************************************************************/ |
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/* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */ |
/* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */ |
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/* |
/* |
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#define FIX_2_562915447 ((int) 20995) /* FIX(2.562915447) */ |
#define FIX_2_562915447 ((int) 20995) /* FIX(2.562915447) */ |
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#define FIX_3_072711026 ((int) 25172) /* FIX(3.072711026) */ |
#define FIX_3_072711026 ((int) 25172) /* FIX(3.072711026) */ |
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// function pointer |
/* function pointer */ |
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fdctFuncPtr fdct; |
fdctFuncPtr fdct; |
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/* |
/* |
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* Perform an integer forward DCT on one block of samples. |
* Perform an integer forward DCT on one block of samples. |
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*/ |
*/ |
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void fdct_int32(short * const block) |
void |
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fdct_int32(short *const block) |
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{ |
{ |
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int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; |
int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; |
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int tmp10, tmp11, tmp12, tmp13; |
int tmp10, tmp11, tmp12, tmp13; |
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dataptr = data; |
dataptr = data; |
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blkptr = block; |
blkptr = block; |
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for (i = 0; i < 8; i++) |
for (i = 0; i < 8; i++) { |
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{ |
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tmp0 = blkptr[0] + blkptr[7]; |
tmp0 = blkptr[0] + blkptr[7]; |
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tmp7 = blkptr[0] - blkptr[7]; |
tmp7 = blkptr[0] - blkptr[7]; |
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tmp1 = blkptr[1] + blkptr[6]; |
tmp1 = blkptr[1] + blkptr[6]; |
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dataptr[4] = (tmp10 - tmp11) << PASS1_BITS; |
dataptr[4] = (tmp10 - tmp11) << PASS1_BITS; |
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z1 = (tmp12 + tmp13) * FIX_0_541196100; |
z1 = (tmp12 + tmp13) * FIX_0_541196100; |
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dataptr[2] = DESCALE(z1 + tmp13 * FIX_0_765366865, CONST_BITS - PASS1_BITS); |
dataptr[2] = |
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dataptr[6] = DESCALE(z1 + tmp12 * (-FIX_1_847759065), CONST_BITS - PASS1_BITS); |
DESCALE(z1 + tmp13 * FIX_0_765366865, CONST_BITS - PASS1_BITS); |
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dataptr[6] = |
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DESCALE(z1 + tmp12 * (-FIX_1_847759065), CONST_BITS - PASS1_BITS); |
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/* Odd part per figure 8 --- note paper omits factor of sqrt(2). |
/* Odd part per figure 8 --- note paper omits factor of sqrt(2). |
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* cK represents cos(K*pi/16). |
* cK represents cos(K*pi/16). |
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*/ |
*/ |
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dataptr = data; |
dataptr = data; |
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for (i = 0; i < 8; i++) |
for (i = 0; i < 8; i++) { |
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{ |
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tmp0 = dataptr[0] + dataptr[56]; |
tmp0 = dataptr[0] + dataptr[56]; |
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tmp7 = dataptr[0] - dataptr[56]; |
tmp7 = dataptr[0] - dataptr[56]; |
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tmp1 = dataptr[8] + dataptr[48]; |
tmp1 = dataptr[8] + dataptr[48]; |
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dataptr[32] = DESCALE(tmp10 - tmp11, PASS1_BITS); |
dataptr[32] = DESCALE(tmp10 - tmp11, PASS1_BITS); |
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z1 = (tmp12 + tmp13) * FIX_0_541196100; |
z1 = (tmp12 + tmp13) * FIX_0_541196100; |
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dataptr[16] = DESCALE(z1 + tmp13 * FIX_0_765366865, CONST_BITS + PASS1_BITS); |
dataptr[16] = |
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dataptr[48] = DESCALE(z1 + tmp12 * (-FIX_1_847759065), CONST_BITS + PASS1_BITS); |
DESCALE(z1 + tmp13 * FIX_0_765366865, CONST_BITS + PASS1_BITS); |
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dataptr[48] = |
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DESCALE(z1 + tmp12 * (-FIX_1_847759065), CONST_BITS + PASS1_BITS); |
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/* Odd part per figure 8 --- note paper omits factor of sqrt(2). |
/* Odd part per figure 8 --- note paper omits factor of sqrt(2). |
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* cK represents cos(K*pi/16). |
* cK represents cos(K*pi/16). |
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for (i = 0; i < 64; i++) |
for (i = 0; i < 64; i++) |
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block[i] = (short int) DESCALE(data[i], 3); |
block[i] = (short int) DESCALE(data[i], 3); |
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} |
} |
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