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![Diego Biurrun](/assets/img/avatar_default.png)
Passing an explicit filename to this command is only necessary if the documentation in the @file block refers to a file different from the one the block resides in. Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk
1158 lines
43 KiB
C
1158 lines
43 KiB
C
/*
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* jrevdct.c
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*
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* This file is part of the Independent JPEG Group's software.
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*
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* The authors make NO WARRANTY or representation, either express or implied,
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* with respect to this software, its quality, accuracy, merchantability, or
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* fitness for a particular purpose. This software is provided "AS IS", and
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* you, its user, assume the entire risk as to its quality and accuracy.
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*
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* This software is copyright (C) 1991, 1992, Thomas G. Lane.
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* All Rights Reserved except as specified below.
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*
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* Permission is hereby granted to use, copy, modify, and distribute this
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* software (or portions thereof) for any purpose, without fee, subject to
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* these conditions:
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* (1) If any part of the source code for this software is distributed, then
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* this README file must be included, with this copyright and no-warranty
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* notice unaltered; and any additions, deletions, or changes to the original
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* files must be clearly indicated in accompanying documentation.
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* (2) If only executable code is distributed, then the accompanying
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* documentation must state that "this software is based in part on the work
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* of the Independent JPEG Group".
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* (3) Permission for use of this software is granted only if the user accepts
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* full responsibility for any undesirable consequences; the authors accept
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* NO LIABILITY for damages of any kind.
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*
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* These conditions apply to any software derived from or based on the IJG
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* code, not just to the unmodified library. If you use our work, you ought
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* to acknowledge us.
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*
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* Permission is NOT granted for the use of any IJG author's name or company
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* name in advertising or publicity relating to this software or products
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* derived from it. This software may be referred to only as "the Independent
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* JPEG Group's software".
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*
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* We specifically permit and encourage the use of this software as the basis
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* of commercial products, provided that all warranty or liability claims are
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* assumed by the product vendor.
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*
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* This file contains the basic inverse-DCT transformation subroutine.
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*
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* This implementation is based on an algorithm described in
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* C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
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* Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
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* Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
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* The primary algorithm described there uses 11 multiplies and 29 adds.
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* We use their alternate method with 12 multiplies and 32 adds.
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* The advantage of this method is that no data path contains more than one
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* multiplication; this allows a very simple and accurate implementation in
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* scaled fixed-point arithmetic, with a minimal number of shifts.
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*
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* I've made lots of modifications to attempt to take advantage of the
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* sparse nature of the DCT matrices we're getting. Although the logic
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* is cumbersome, it's straightforward and the resulting code is much
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* faster.
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*
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* A better way to do this would be to pass in the DCT block as a sparse
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* matrix, perhaps with the difference cases encoded.
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*/
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/**
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* @file
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* Independent JPEG Group's LLM idct.
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*/
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#include "libavutil/common.h"
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#include "dsputil.h"
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#define EIGHT_BIT_SAMPLES
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#define DCTSIZE 8
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#define DCTSIZE2 64
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#define GLOBAL
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#define RIGHT_SHIFT(x, n) ((x) >> (n))
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typedef DCTELEM DCTBLOCK[DCTSIZE2];
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#define CONST_BITS 13
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/*
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* This routine is specialized to the case DCTSIZE = 8.
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*/
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#if DCTSIZE != 8
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Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
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#endif
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/*
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* A 2-D IDCT can be done by 1-D IDCT on each row followed by 1-D IDCT
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* on each column. Direct algorithms are also available, but they are
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* much more complex and seem not to be any faster when reduced to code.
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*
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* The poop on this scaling stuff is as follows:
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*
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* Each 1-D IDCT step produces outputs which are a factor of sqrt(N)
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* larger than the true IDCT outputs. The final outputs are therefore
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* a factor of N larger than desired; since N=8 this can be cured by
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* a simple right shift at the end of the algorithm. The advantage of
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* this arrangement is that we save two multiplications per 1-D IDCT,
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* because the y0 and y4 inputs need not be divided by sqrt(N).
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*
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* We have to do addition and subtraction of the integer inputs, which
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* is no problem, and multiplication by fractional constants, which is
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* a problem to do in integer arithmetic. We multiply all the constants
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* by CONST_SCALE and convert them to integer constants (thus retaining
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* CONST_BITS bits of precision in the constants). After doing a
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* multiplication we have to divide the product by CONST_SCALE, with proper
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* rounding, to produce the correct output. This division can be done
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* cheaply as a right shift of CONST_BITS bits. We postpone shifting
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* as long as possible so that partial sums can be added together with
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* full fractional precision.
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*
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* The outputs of the first pass are scaled up by PASS1_BITS bits so that
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* they are represented to better-than-integral precision. These outputs
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* require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
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* with the recommended scaling. (To scale up 12-bit sample data further, an
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* intermediate int32 array would be needed.)
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*
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* To avoid overflow of the 32-bit intermediate results in pass 2, we must
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* have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
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* shows that the values given below are the most effective.
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*/
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#ifdef EIGHT_BIT_SAMPLES
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#define PASS1_BITS 2
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#else
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#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
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#endif
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#define ONE ((int32_t) 1)
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#define CONST_SCALE (ONE << CONST_BITS)
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/* Convert a positive real constant to an integer scaled by CONST_SCALE.
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* IMPORTANT: if your compiler doesn't do this arithmetic at compile time,
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* you will pay a significant penalty in run time. In that case, figure
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* the correct integer constant values and insert them by hand.
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*/
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/* Actually FIX is no longer used, we precomputed them all */
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#define FIX(x) ((int32_t) ((x) * CONST_SCALE + 0.5))
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/* Descale and correctly round an int32_t value that's scaled by N bits.
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* We assume RIGHT_SHIFT rounds towards minus infinity, so adding
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* the fudge factor is correct for either sign of X.
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*/
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#define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
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/* Multiply an int32_t variable by an int32_t constant to yield an int32_t result.
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* For 8-bit samples with the recommended scaling, all the variable
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* and constant values involved are no more than 16 bits wide, so a
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* 16x16->32 bit multiply can be used instead of a full 32x32 multiply;
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* this provides a useful speedup on many machines.
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* There is no way to specify a 16x16->32 multiply in portable C, but
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* some C compilers will do the right thing if you provide the correct
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* combination of casts.
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* NB: for 12-bit samples, a full 32-bit multiplication will be needed.
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*/
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#ifdef EIGHT_BIT_SAMPLES
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#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
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#define MULTIPLY(var,const) (((int16_t) (var)) * ((int16_t) (const)))
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#endif
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#ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */
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#define MULTIPLY(var,const) (((int16_t) (var)) * ((int32_t) (const)))
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#endif
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#endif
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#ifndef MULTIPLY /* default definition */
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#define MULTIPLY(var,const) ((var) * (const))
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#endif
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/*
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Unlike our decoder where we approximate the FIXes, we need to use exact
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ones here or successive P-frames will drift too much with Reference frame coding
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*/
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#define FIX_0_211164243 1730
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#define FIX_0_275899380 2260
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#define FIX_0_298631336 2446
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#define FIX_0_390180644 3196
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#define FIX_0_509795579 4176
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#define FIX_0_541196100 4433
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#define FIX_0_601344887 4926
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#define FIX_0_765366865 6270
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#define FIX_0_785694958 6436
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#define FIX_0_899976223 7373
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#define FIX_1_061594337 8697
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#define FIX_1_111140466 9102
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#define FIX_1_175875602 9633
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#define FIX_1_306562965 10703
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#define FIX_1_387039845 11363
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#define FIX_1_451774981 11893
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#define FIX_1_501321110 12299
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#define FIX_1_662939225 13623
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#define FIX_1_847759065 15137
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#define FIX_1_961570560 16069
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#define FIX_2_053119869 16819
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#define FIX_2_172734803 17799
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#define FIX_2_562915447 20995
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#define FIX_3_072711026 25172
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/*
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* Perform the inverse DCT on one block of coefficients.
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*/
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void j_rev_dct(DCTBLOCK data)
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{
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int32_t tmp0, tmp1, tmp2, tmp3;
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int32_t tmp10, tmp11, tmp12, tmp13;
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int32_t z1, z2, z3, z4, z5;
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int32_t d0, d1, d2, d3, d4, d5, d6, d7;
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register DCTELEM *dataptr;
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int rowctr;
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/* Pass 1: process rows. */
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/* Note results are scaled up by sqrt(8) compared to a true IDCT; */
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/* furthermore, we scale the results by 2**PASS1_BITS. */
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dataptr = data;
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for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
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/* Due to quantization, we will usually find that many of the input
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* coefficients are zero, especially the AC terms. We can exploit this
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* by short-circuiting the IDCT calculation for any row in which all
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* the AC terms are zero. In that case each output is equal to the
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* DC coefficient (with scale factor as needed).
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* With typical images and quantization tables, half or more of the
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* row DCT calculations can be simplified this way.
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*/
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register int *idataptr = (int*)dataptr;
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/* WARNING: we do the same permutation as MMX idct to simplify the
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video core */
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d0 = dataptr[0];
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d2 = dataptr[1];
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d4 = dataptr[2];
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d6 = dataptr[3];
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d1 = dataptr[4];
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d3 = dataptr[5];
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d5 = dataptr[6];
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d7 = dataptr[7];
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if ((d1 | d2 | d3 | d4 | d5 | d6 | d7) == 0) {
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/* AC terms all zero */
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if (d0) {
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/* Compute a 32 bit value to assign. */
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DCTELEM dcval = (DCTELEM) (d0 << PASS1_BITS);
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register int v = (dcval & 0xffff) | ((dcval << 16) & 0xffff0000);
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idataptr[0] = v;
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idataptr[1] = v;
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idataptr[2] = v;
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idataptr[3] = v;
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}
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dataptr += DCTSIZE; /* advance pointer to next row */
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continue;
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}
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/* Even part: reverse the even part of the forward DCT. */
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/* The rotator is sqrt(2)*c(-6). */
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{
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if (d6) {
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if (d2) {
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/* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
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z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
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tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
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tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
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tmp0 = (d0 + d4) << CONST_BITS;
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tmp1 = (d0 - d4) << CONST_BITS;
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tmp10 = tmp0 + tmp3;
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tmp13 = tmp0 - tmp3;
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tmp11 = tmp1 + tmp2;
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tmp12 = tmp1 - tmp2;
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} else {
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/* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
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tmp2 = MULTIPLY(-d6, FIX_1_306562965);
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tmp3 = MULTIPLY(d6, FIX_0_541196100);
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tmp0 = (d0 + d4) << CONST_BITS;
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tmp1 = (d0 - d4) << CONST_BITS;
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tmp10 = tmp0 + tmp3;
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tmp13 = tmp0 - tmp3;
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tmp11 = tmp1 + tmp2;
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tmp12 = tmp1 - tmp2;
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}
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} else {
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if (d2) {
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/* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
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tmp2 = MULTIPLY(d2, FIX_0_541196100);
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tmp3 = MULTIPLY(d2, FIX_1_306562965);
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tmp0 = (d0 + d4) << CONST_BITS;
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tmp1 = (d0 - d4) << CONST_BITS;
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tmp10 = tmp0 + tmp3;
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tmp13 = tmp0 - tmp3;
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tmp11 = tmp1 + tmp2;
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tmp12 = tmp1 - tmp2;
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} else {
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/* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
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tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
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tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
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}
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}
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/* Odd part per figure 8; the matrix is unitary and hence its
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* transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
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*/
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if (d7) {
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if (d5) {
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if (d3) {
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if (d1) {
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/* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
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z1 = d7 + d1;
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z2 = d5 + d3;
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z3 = d7 + d3;
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z4 = d5 + d1;
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z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
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tmp0 = MULTIPLY(d7, FIX_0_298631336);
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tmp1 = MULTIPLY(d5, FIX_2_053119869);
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tmp2 = MULTIPLY(d3, FIX_3_072711026);
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tmp3 = MULTIPLY(d1, FIX_1_501321110);
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z1 = MULTIPLY(-z1, FIX_0_899976223);
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z2 = MULTIPLY(-z2, FIX_2_562915447);
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z3 = MULTIPLY(-z3, FIX_1_961570560);
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z4 = MULTIPLY(-z4, FIX_0_390180644);
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z3 += z5;
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z4 += z5;
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tmp0 += z1 + z3;
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tmp1 += z2 + z4;
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tmp2 += z2 + z3;
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tmp3 += z1 + z4;
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} else {
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/* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
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z2 = d5 + d3;
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z3 = d7 + d3;
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z5 = MULTIPLY(z3 + d5, FIX_1_175875602);
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tmp0 = MULTIPLY(d7, FIX_0_298631336);
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tmp1 = MULTIPLY(d5, FIX_2_053119869);
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tmp2 = MULTIPLY(d3, FIX_3_072711026);
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z1 = MULTIPLY(-d7, FIX_0_899976223);
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z2 = MULTIPLY(-z2, FIX_2_562915447);
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z3 = MULTIPLY(-z3, FIX_1_961570560);
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z4 = MULTIPLY(-d5, FIX_0_390180644);
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z3 += z5;
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z4 += z5;
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tmp0 += z1 + z3;
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tmp1 += z2 + z4;
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tmp2 += z2 + z3;
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tmp3 = z1 + z4;
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}
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} else {
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if (d1) {
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/* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
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z1 = d7 + d1;
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z4 = d5 + d1;
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z5 = MULTIPLY(d7 + z4, FIX_1_175875602);
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tmp0 = MULTIPLY(d7, FIX_0_298631336);
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tmp1 = MULTIPLY(d5, FIX_2_053119869);
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tmp3 = MULTIPLY(d1, FIX_1_501321110);
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z1 = MULTIPLY(-z1, FIX_0_899976223);
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z2 = MULTIPLY(-d5, FIX_2_562915447);
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z3 = MULTIPLY(-d7, FIX_1_961570560);
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z4 = MULTIPLY(-z4, FIX_0_390180644);
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z3 += z5;
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z4 += z5;
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tmp0 += z1 + z3;
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tmp1 += z2 + z4;
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tmp2 = z2 + z3;
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tmp3 += z1 + z4;
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} else {
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/* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
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tmp0 = MULTIPLY(-d7, FIX_0_601344887);
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z1 = MULTIPLY(-d7, FIX_0_899976223);
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z3 = MULTIPLY(-d7, FIX_1_961570560);
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tmp1 = MULTIPLY(-d5, FIX_0_509795579);
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z2 = MULTIPLY(-d5, FIX_2_562915447);
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z4 = MULTIPLY(-d5, FIX_0_390180644);
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z5 = MULTIPLY(d5 + d7, FIX_1_175875602);
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z3 += z5;
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z4 += z5;
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tmp0 += z3;
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tmp1 += z4;
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tmp2 = z2 + z3;
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tmp3 = z1 + z4;
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}
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}
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} else {
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if (d3) {
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if (d1) {
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/* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
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z1 = d7 + d1;
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z3 = d7 + d3;
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z5 = MULTIPLY(z3 + d1, FIX_1_175875602);
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tmp0 = MULTIPLY(d7, FIX_0_298631336);
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tmp2 = MULTIPLY(d3, FIX_3_072711026);
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tmp3 = MULTIPLY(d1, FIX_1_501321110);
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z1 = MULTIPLY(-z1, FIX_0_899976223);
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z2 = MULTIPLY(-d3, FIX_2_562915447);
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z3 = MULTIPLY(-z3, FIX_1_961570560);
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z4 = MULTIPLY(-d1, FIX_0_390180644);
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z3 += z5;
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z4 += z5;
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tmp0 += z1 + z3;
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tmp1 = z2 + z4;
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tmp2 += z2 + z3;
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tmp3 += z1 + z4;
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} else {
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/* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
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z3 = d7 + d3;
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tmp0 = MULTIPLY(-d7, FIX_0_601344887);
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z1 = MULTIPLY(-d7, FIX_0_899976223);
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tmp2 = MULTIPLY(d3, FIX_0_509795579);
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|
z2 = MULTIPLY(-d3, FIX_2_562915447);
|
|
z5 = MULTIPLY(z3, FIX_1_175875602);
|
|
z3 = MULTIPLY(-z3, FIX_0_785694958);
|
|
|
|
tmp0 += z3;
|
|
tmp1 = z2 + z5;
|
|
tmp2 += z3;
|
|
tmp3 = z1 + z5;
|
|
}
|
|
} else {
|
|
if (d1) {
|
|
/* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
|
|
z1 = d7 + d1;
|
|
z5 = MULTIPLY(z1, FIX_1_175875602);
|
|
|
|
z1 = MULTIPLY(z1, FIX_0_275899380);
|
|
z3 = MULTIPLY(-d7, FIX_1_961570560);
|
|
tmp0 = MULTIPLY(-d7, FIX_1_662939225);
|
|
z4 = MULTIPLY(-d1, FIX_0_390180644);
|
|
tmp3 = MULTIPLY(d1, FIX_1_111140466);
|
|
|
|
tmp0 += z1;
|
|
tmp1 = z4 + z5;
|
|
tmp2 = z3 + z5;
|
|
tmp3 += z1;
|
|
} else {
|
|
/* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
|
|
tmp0 = MULTIPLY(-d7, FIX_1_387039845);
|
|
tmp1 = MULTIPLY(d7, FIX_1_175875602);
|
|
tmp2 = MULTIPLY(-d7, FIX_0_785694958);
|
|
tmp3 = MULTIPLY(d7, FIX_0_275899380);
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if (d5) {
|
|
if (d3) {
|
|
if (d1) {
|
|
/* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
|
|
z2 = d5 + d3;
|
|
z4 = d5 + d1;
|
|
z5 = MULTIPLY(d3 + z4, FIX_1_175875602);
|
|
|
|
tmp1 = MULTIPLY(d5, FIX_2_053119869);
|
|
tmp2 = MULTIPLY(d3, FIX_3_072711026);
|
|
tmp3 = MULTIPLY(d1, FIX_1_501321110);
|
|
z1 = MULTIPLY(-d1, FIX_0_899976223);
|
|
z2 = MULTIPLY(-z2, FIX_2_562915447);
|
|
z3 = MULTIPLY(-d3, FIX_1_961570560);
|
|
z4 = MULTIPLY(-z4, FIX_0_390180644);
|
|
|
|
z3 += z5;
|
|
z4 += z5;
|
|
|
|
tmp0 = z1 + z3;
|
|
tmp1 += z2 + z4;
|
|
tmp2 += z2 + z3;
|
|
tmp3 += z1 + z4;
|
|
} else {
|
|
/* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
|
|
z2 = d5 + d3;
|
|
|
|
z5 = MULTIPLY(z2, FIX_1_175875602);
|
|
tmp1 = MULTIPLY(d5, FIX_1_662939225);
|
|
z4 = MULTIPLY(-d5, FIX_0_390180644);
|
|
z2 = MULTIPLY(-z2, FIX_1_387039845);
|
|
tmp2 = MULTIPLY(d3, FIX_1_111140466);
|
|
z3 = MULTIPLY(-d3, FIX_1_961570560);
|
|
|
|
tmp0 = z3 + z5;
|
|
tmp1 += z2;
|
|
tmp2 += z2;
|
|
tmp3 = z4 + z5;
|
|
}
|
|
} else {
|
|
if (d1) {
|
|
/* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
|
|
z4 = d5 + d1;
|
|
|
|
z5 = MULTIPLY(z4, FIX_1_175875602);
|
|
z1 = MULTIPLY(-d1, FIX_0_899976223);
|
|
tmp3 = MULTIPLY(d1, FIX_0_601344887);
|
|
tmp1 = MULTIPLY(-d5, FIX_0_509795579);
|
|
z2 = MULTIPLY(-d5, FIX_2_562915447);
|
|
z4 = MULTIPLY(z4, FIX_0_785694958);
|
|
|
|
tmp0 = z1 + z5;
|
|
tmp1 += z4;
|
|
tmp2 = z2 + z5;
|
|
tmp3 += z4;
|
|
} else {
|
|
/* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
|
|
tmp0 = MULTIPLY(d5, FIX_1_175875602);
|
|
tmp1 = MULTIPLY(d5, FIX_0_275899380);
|
|
tmp2 = MULTIPLY(-d5, FIX_1_387039845);
|
|
tmp3 = MULTIPLY(d5, FIX_0_785694958);
|
|
}
|
|
}
|
|
} else {
|
|
if (d3) {
|
|
if (d1) {
|
|
/* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
|
|
z5 = d1 + d3;
|
|
tmp3 = MULTIPLY(d1, FIX_0_211164243);
|
|
tmp2 = MULTIPLY(-d3, FIX_1_451774981);
|
|
z1 = MULTIPLY(d1, FIX_1_061594337);
|
|
z2 = MULTIPLY(-d3, FIX_2_172734803);
|
|
z4 = MULTIPLY(z5, FIX_0_785694958);
|
|
z5 = MULTIPLY(z5, FIX_1_175875602);
|
|
|
|
tmp0 = z1 - z4;
|
|
tmp1 = z2 + z4;
|
|
tmp2 += z5;
|
|
tmp3 += z5;
|
|
} else {
|
|
/* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
|
|
tmp0 = MULTIPLY(-d3, FIX_0_785694958);
|
|
tmp1 = MULTIPLY(-d3, FIX_1_387039845);
|
|
tmp2 = MULTIPLY(-d3, FIX_0_275899380);
|
|
tmp3 = MULTIPLY(d3, FIX_1_175875602);
|
|
}
|
|
} else {
|
|
if (d1) {
|
|
/* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
|
|
tmp0 = MULTIPLY(d1, FIX_0_275899380);
|
|
tmp1 = MULTIPLY(d1, FIX_0_785694958);
|
|
tmp2 = MULTIPLY(d1, FIX_1_175875602);
|
|
tmp3 = MULTIPLY(d1, FIX_1_387039845);
|
|
} else {
|
|
/* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
|
|
tmp0 = tmp1 = tmp2 = tmp3 = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
|
|
|
|
dataptr[0] = (DCTELEM) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
|
|
dataptr[7] = (DCTELEM) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
|
|
dataptr[1] = (DCTELEM) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
|
|
dataptr[6] = (DCTELEM) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
|
|
dataptr[2] = (DCTELEM) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
|
|
dataptr[5] = (DCTELEM) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
|
|
dataptr[3] = (DCTELEM) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
|
|
dataptr[4] = (DCTELEM) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
|
|
|
|
dataptr += DCTSIZE; /* advance pointer to next row */
|
|
}
|
|
|
|
/* Pass 2: process columns. */
|
|
/* Note that we must descale the results by a factor of 8 == 2**3, */
|
|
/* and also undo the PASS1_BITS scaling. */
|
|
|
|
dataptr = data;
|
|
for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
|
|
/* Columns of zeroes can be exploited in the same way as we did with rows.
|
|
* However, the row calculation has created many nonzero AC terms, so the
|
|
* simplification applies less often (typically 5% to 10% of the time).
|
|
* On machines with very fast multiplication, it's possible that the
|
|
* test takes more time than it's worth. In that case this section
|
|
* may be commented out.
|
|
*/
|
|
|
|
d0 = dataptr[DCTSIZE*0];
|
|
d1 = dataptr[DCTSIZE*1];
|
|
d2 = dataptr[DCTSIZE*2];
|
|
d3 = dataptr[DCTSIZE*3];
|
|
d4 = dataptr[DCTSIZE*4];
|
|
d5 = dataptr[DCTSIZE*5];
|
|
d6 = dataptr[DCTSIZE*6];
|
|
d7 = dataptr[DCTSIZE*7];
|
|
|
|
/* Even part: reverse the even part of the forward DCT. */
|
|
/* The rotator is sqrt(2)*c(-6). */
|
|
if (d6) {
|
|
if (d2) {
|
|
/* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
|
|
z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
|
|
tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
|
|
tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
} else {
|
|
/* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
|
|
tmp2 = MULTIPLY(-d6, FIX_1_306562965);
|
|
tmp3 = MULTIPLY(d6, FIX_0_541196100);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
}
|
|
} else {
|
|
if (d2) {
|
|
/* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
|
|
tmp2 = MULTIPLY(d2, FIX_0_541196100);
|
|
tmp3 = MULTIPLY(d2, FIX_1_306562965);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
} else {
|
|
/* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
|
|
tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
|
|
tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
|
|
}
|
|
}
|
|
|
|
/* Odd part per figure 8; the matrix is unitary and hence its
|
|
* transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
|
|
*/
|
|
if (d7) {
|
|
if (d5) {
|
|
if (d3) {
|
|
if (d1) {
|
|
/* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
|
|
z1 = d7 + d1;
|
|
z2 = d5 + d3;
|
|
z3 = d7 + d3;
|
|
z4 = d5 + d1;
|
|
z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
|
|
|
|
tmp0 = MULTIPLY(d7, FIX_0_298631336);
|
|
tmp1 = MULTIPLY(d5, FIX_2_053119869);
|
|
tmp2 = MULTIPLY(d3, FIX_3_072711026);
|
|
tmp3 = MULTIPLY(d1, FIX_1_501321110);
|
|
z1 = MULTIPLY(-z1, FIX_0_899976223);
|
|
z2 = MULTIPLY(-z2, FIX_2_562915447);
|
|
z3 = MULTIPLY(-z3, FIX_1_961570560);
|
|
z4 = MULTIPLY(-z4, FIX_0_390180644);
|
|
|
|
z3 += z5;
|
|
z4 += z5;
|
|
|
|
tmp0 += z1 + z3;
|
|
tmp1 += z2 + z4;
|
|
tmp2 += z2 + z3;
|
|
tmp3 += z1 + z4;
|
|
} else {
|
|
/* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
|
|
z2 = d5 + d3;
|
|
z3 = d7 + d3;
|
|
z5 = MULTIPLY(z3 + d5, FIX_1_175875602);
|
|
|
|
tmp0 = MULTIPLY(d7, FIX_0_298631336);
|
|
tmp1 = MULTIPLY(d5, FIX_2_053119869);
|
|
tmp2 = MULTIPLY(d3, FIX_3_072711026);
|
|
z1 = MULTIPLY(-d7, FIX_0_899976223);
|
|
z2 = MULTIPLY(-z2, FIX_2_562915447);
|
|
z3 = MULTIPLY(-z3, FIX_1_961570560);
|
|
z4 = MULTIPLY(-d5, FIX_0_390180644);
|
|
|
|
z3 += z5;
|
|
z4 += z5;
|
|
|
|
tmp0 += z1 + z3;
|
|
tmp1 += z2 + z4;
|
|
tmp2 += z2 + z3;
|
|
tmp3 = z1 + z4;
|
|
}
|
|
} else {
|
|
if (d1) {
|
|
/* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
|
|
z1 = d7 + d1;
|
|
z3 = d7;
|
|
z4 = d5 + d1;
|
|
z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
|
|
|
|
tmp0 = MULTIPLY(d7, FIX_0_298631336);
|
|
tmp1 = MULTIPLY(d5, FIX_2_053119869);
|
|
tmp3 = MULTIPLY(d1, FIX_1_501321110);
|
|
z1 = MULTIPLY(-z1, FIX_0_899976223);
|
|
z2 = MULTIPLY(-d5, FIX_2_562915447);
|
|
z3 = MULTIPLY(-d7, FIX_1_961570560);
|
|
z4 = MULTIPLY(-z4, FIX_0_390180644);
|
|
|
|
z3 += z5;
|
|
z4 += z5;
|
|
|
|
tmp0 += z1 + z3;
|
|
tmp1 += z2 + z4;
|
|
tmp2 = z2 + z3;
|
|
tmp3 += z1 + z4;
|
|
} else {
|
|
/* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
|
|
tmp0 = MULTIPLY(-d7, FIX_0_601344887);
|
|
z1 = MULTIPLY(-d7, FIX_0_899976223);
|
|
z3 = MULTIPLY(-d7, FIX_1_961570560);
|
|
tmp1 = MULTIPLY(-d5, FIX_0_509795579);
|
|
z2 = MULTIPLY(-d5, FIX_2_562915447);
|
|
z4 = MULTIPLY(-d5, FIX_0_390180644);
|
|
z5 = MULTIPLY(d5 + d7, FIX_1_175875602);
|
|
|
|
z3 += z5;
|
|
z4 += z5;
|
|
|
|
tmp0 += z3;
|
|
tmp1 += z4;
|
|
tmp2 = z2 + z3;
|
|
tmp3 = z1 + z4;
|
|
}
|
|
}
|
|
} else {
|
|
if (d3) {
|
|
if (d1) {
|
|
/* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
|
|
z1 = d7 + d1;
|
|
z3 = d7 + d3;
|
|
z5 = MULTIPLY(z3 + d1, FIX_1_175875602);
|
|
|
|
tmp0 = MULTIPLY(d7, FIX_0_298631336);
|
|
tmp2 = MULTIPLY(d3, FIX_3_072711026);
|
|
tmp3 = MULTIPLY(d1, FIX_1_501321110);
|
|
z1 = MULTIPLY(-z1, FIX_0_899976223);
|
|
z2 = MULTIPLY(-d3, FIX_2_562915447);
|
|
z3 = MULTIPLY(-z3, FIX_1_961570560);
|
|
z4 = MULTIPLY(-d1, FIX_0_390180644);
|
|
|
|
z3 += z5;
|
|
z4 += z5;
|
|
|
|
tmp0 += z1 + z3;
|
|
tmp1 = z2 + z4;
|
|
tmp2 += z2 + z3;
|
|
tmp3 += z1 + z4;
|
|
} else {
|
|
/* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
|
|
z3 = d7 + d3;
|
|
|
|
tmp0 = MULTIPLY(-d7, FIX_0_601344887);
|
|
z1 = MULTIPLY(-d7, FIX_0_899976223);
|
|
tmp2 = MULTIPLY(d3, FIX_0_509795579);
|
|
z2 = MULTIPLY(-d3, FIX_2_562915447);
|
|
z5 = MULTIPLY(z3, FIX_1_175875602);
|
|
z3 = MULTIPLY(-z3, FIX_0_785694958);
|
|
|
|
tmp0 += z3;
|
|
tmp1 = z2 + z5;
|
|
tmp2 += z3;
|
|
tmp3 = z1 + z5;
|
|
}
|
|
} else {
|
|
if (d1) {
|
|
/* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
|
|
z1 = d7 + d1;
|
|
z5 = MULTIPLY(z1, FIX_1_175875602);
|
|
|
|
z1 = MULTIPLY(z1, FIX_0_275899380);
|
|
z3 = MULTIPLY(-d7, FIX_1_961570560);
|
|
tmp0 = MULTIPLY(-d7, FIX_1_662939225);
|
|
z4 = MULTIPLY(-d1, FIX_0_390180644);
|
|
tmp3 = MULTIPLY(d1, FIX_1_111140466);
|
|
|
|
tmp0 += z1;
|
|
tmp1 = z4 + z5;
|
|
tmp2 = z3 + z5;
|
|
tmp3 += z1;
|
|
} else {
|
|
/* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
|
|
tmp0 = MULTIPLY(-d7, FIX_1_387039845);
|
|
tmp1 = MULTIPLY(d7, FIX_1_175875602);
|
|
tmp2 = MULTIPLY(-d7, FIX_0_785694958);
|
|
tmp3 = MULTIPLY(d7, FIX_0_275899380);
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if (d5) {
|
|
if (d3) {
|
|
if (d1) {
|
|
/* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
|
|
z2 = d5 + d3;
|
|
z4 = d5 + d1;
|
|
z5 = MULTIPLY(d3 + z4, FIX_1_175875602);
|
|
|
|
tmp1 = MULTIPLY(d5, FIX_2_053119869);
|
|
tmp2 = MULTIPLY(d3, FIX_3_072711026);
|
|
tmp3 = MULTIPLY(d1, FIX_1_501321110);
|
|
z1 = MULTIPLY(-d1, FIX_0_899976223);
|
|
z2 = MULTIPLY(-z2, FIX_2_562915447);
|
|
z3 = MULTIPLY(-d3, FIX_1_961570560);
|
|
z4 = MULTIPLY(-z4, FIX_0_390180644);
|
|
|
|
z3 += z5;
|
|
z4 += z5;
|
|
|
|
tmp0 = z1 + z3;
|
|
tmp1 += z2 + z4;
|
|
tmp2 += z2 + z3;
|
|
tmp3 += z1 + z4;
|
|
} else {
|
|
/* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
|
|
z2 = d5 + d3;
|
|
|
|
z5 = MULTIPLY(z2, FIX_1_175875602);
|
|
tmp1 = MULTIPLY(d5, FIX_1_662939225);
|
|
z4 = MULTIPLY(-d5, FIX_0_390180644);
|
|
z2 = MULTIPLY(-z2, FIX_1_387039845);
|
|
tmp2 = MULTIPLY(d3, FIX_1_111140466);
|
|
z3 = MULTIPLY(-d3, FIX_1_961570560);
|
|
|
|
tmp0 = z3 + z5;
|
|
tmp1 += z2;
|
|
tmp2 += z2;
|
|
tmp3 = z4 + z5;
|
|
}
|
|
} else {
|
|
if (d1) {
|
|
/* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
|
|
z4 = d5 + d1;
|
|
|
|
z5 = MULTIPLY(z4, FIX_1_175875602);
|
|
z1 = MULTIPLY(-d1, FIX_0_899976223);
|
|
tmp3 = MULTIPLY(d1, FIX_0_601344887);
|
|
tmp1 = MULTIPLY(-d5, FIX_0_509795579);
|
|
z2 = MULTIPLY(-d5, FIX_2_562915447);
|
|
z4 = MULTIPLY(z4, FIX_0_785694958);
|
|
|
|
tmp0 = z1 + z5;
|
|
tmp1 += z4;
|
|
tmp2 = z2 + z5;
|
|
tmp3 += z4;
|
|
} else {
|
|
/* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
|
|
tmp0 = MULTIPLY(d5, FIX_1_175875602);
|
|
tmp1 = MULTIPLY(d5, FIX_0_275899380);
|
|
tmp2 = MULTIPLY(-d5, FIX_1_387039845);
|
|
tmp3 = MULTIPLY(d5, FIX_0_785694958);
|
|
}
|
|
}
|
|
} else {
|
|
if (d3) {
|
|
if (d1) {
|
|
/* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
|
|
z5 = d1 + d3;
|
|
tmp3 = MULTIPLY(d1, FIX_0_211164243);
|
|
tmp2 = MULTIPLY(-d3, FIX_1_451774981);
|
|
z1 = MULTIPLY(d1, FIX_1_061594337);
|
|
z2 = MULTIPLY(-d3, FIX_2_172734803);
|
|
z4 = MULTIPLY(z5, FIX_0_785694958);
|
|
z5 = MULTIPLY(z5, FIX_1_175875602);
|
|
|
|
tmp0 = z1 - z4;
|
|
tmp1 = z2 + z4;
|
|
tmp2 += z5;
|
|
tmp3 += z5;
|
|
} else {
|
|
/* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
|
|
tmp0 = MULTIPLY(-d3, FIX_0_785694958);
|
|
tmp1 = MULTIPLY(-d3, FIX_1_387039845);
|
|
tmp2 = MULTIPLY(-d3, FIX_0_275899380);
|
|
tmp3 = MULTIPLY(d3, FIX_1_175875602);
|
|
}
|
|
} else {
|
|
if (d1) {
|
|
/* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
|
|
tmp0 = MULTIPLY(d1, FIX_0_275899380);
|
|
tmp1 = MULTIPLY(d1, FIX_0_785694958);
|
|
tmp2 = MULTIPLY(d1, FIX_1_175875602);
|
|
tmp3 = MULTIPLY(d1, FIX_1_387039845);
|
|
} else {
|
|
/* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
|
|
tmp0 = tmp1 = tmp2 = tmp3 = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
|
|
|
|
dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp3,
|
|
CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp10 - tmp3,
|
|
CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp11 + tmp2,
|
|
CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(tmp11 - tmp2,
|
|
CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp12 + tmp1,
|
|
CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12 - tmp1,
|
|
CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp13 + tmp0,
|
|
CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp13 - tmp0,
|
|
CONST_BITS+PASS1_BITS+3);
|
|
|
|
dataptr++; /* advance pointer to next column */
|
|
}
|
|
}
|
|
|
|
#undef DCTSIZE
|
|
#define DCTSIZE 4
|
|
#define DCTSTRIDE 8
|
|
|
|
void j_rev_dct4(DCTBLOCK data)
|
|
{
|
|
int32_t tmp0, tmp1, tmp2, tmp3;
|
|
int32_t tmp10, tmp11, tmp12, tmp13;
|
|
int32_t z1;
|
|
int32_t d0, d2, d4, d6;
|
|
register DCTELEM *dataptr;
|
|
int rowctr;
|
|
|
|
/* Pass 1: process rows. */
|
|
/* Note results are scaled up by sqrt(8) compared to a true IDCT; */
|
|
/* furthermore, we scale the results by 2**PASS1_BITS. */
|
|
|
|
data[0] += 4;
|
|
|
|
dataptr = data;
|
|
|
|
for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
|
|
/* Due to quantization, we will usually find that many of the input
|
|
* coefficients are zero, especially the AC terms. We can exploit this
|
|
* by short-circuiting the IDCT calculation for any row in which all
|
|
* the AC terms are zero. In that case each output is equal to the
|
|
* DC coefficient (with scale factor as needed).
|
|
* With typical images and quantization tables, half or more of the
|
|
* row DCT calculations can be simplified this way.
|
|
*/
|
|
|
|
register int *idataptr = (int*)dataptr;
|
|
|
|
d0 = dataptr[0];
|
|
d2 = dataptr[1];
|
|
d4 = dataptr[2];
|
|
d6 = dataptr[3];
|
|
|
|
if ((d2 | d4 | d6) == 0) {
|
|
/* AC terms all zero */
|
|
if (d0) {
|
|
/* Compute a 32 bit value to assign. */
|
|
DCTELEM dcval = (DCTELEM) (d0 << PASS1_BITS);
|
|
register int v = (dcval & 0xffff) | ((dcval << 16) & 0xffff0000);
|
|
|
|
idataptr[0] = v;
|
|
idataptr[1] = v;
|
|
}
|
|
|
|
dataptr += DCTSTRIDE; /* advance pointer to next row */
|
|
continue;
|
|
}
|
|
|
|
/* Even part: reverse the even part of the forward DCT. */
|
|
/* The rotator is sqrt(2)*c(-6). */
|
|
if (d6) {
|
|
if (d2) {
|
|
/* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
|
|
z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
|
|
tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
|
|
tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
} else {
|
|
/* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
|
|
tmp2 = MULTIPLY(-d6, FIX_1_306562965);
|
|
tmp3 = MULTIPLY(d6, FIX_0_541196100);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
}
|
|
} else {
|
|
if (d2) {
|
|
/* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
|
|
tmp2 = MULTIPLY(d2, FIX_0_541196100);
|
|
tmp3 = MULTIPLY(d2, FIX_1_306562965);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
} else {
|
|
/* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
|
|
tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
|
|
tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
|
|
}
|
|
}
|
|
|
|
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
|
|
|
|
dataptr[0] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
|
|
dataptr[1] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
|
|
dataptr[2] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
|
|
dataptr[3] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);
|
|
|
|
dataptr += DCTSTRIDE; /* advance pointer to next row */
|
|
}
|
|
|
|
/* Pass 2: process columns. */
|
|
/* Note that we must descale the results by a factor of 8 == 2**3, */
|
|
/* and also undo the PASS1_BITS scaling. */
|
|
|
|
dataptr = data;
|
|
for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
|
|
/* Columns of zeroes can be exploited in the same way as we did with rows.
|
|
* However, the row calculation has created many nonzero AC terms, so the
|
|
* simplification applies less often (typically 5% to 10% of the time).
|
|
* On machines with very fast multiplication, it's possible that the
|
|
* test takes more time than it's worth. In that case this section
|
|
* may be commented out.
|
|
*/
|
|
|
|
d0 = dataptr[DCTSTRIDE*0];
|
|
d2 = dataptr[DCTSTRIDE*1];
|
|
d4 = dataptr[DCTSTRIDE*2];
|
|
d6 = dataptr[DCTSTRIDE*3];
|
|
|
|
/* Even part: reverse the even part of the forward DCT. */
|
|
/* The rotator is sqrt(2)*c(-6). */
|
|
if (d6) {
|
|
if (d2) {
|
|
/* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
|
|
z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
|
|
tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
|
|
tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
} else {
|
|
/* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
|
|
tmp2 = MULTIPLY(-d6, FIX_1_306562965);
|
|
tmp3 = MULTIPLY(d6, FIX_0_541196100);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
}
|
|
} else {
|
|
if (d2) {
|
|
/* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
|
|
tmp2 = MULTIPLY(d2, FIX_0_541196100);
|
|
tmp3 = MULTIPLY(d2, FIX_1_306562965);
|
|
|
|
tmp0 = (d0 + d4) << CONST_BITS;
|
|
tmp1 = (d0 - d4) << CONST_BITS;
|
|
|
|
tmp10 = tmp0 + tmp3;
|
|
tmp13 = tmp0 - tmp3;
|
|
tmp11 = tmp1 + tmp2;
|
|
tmp12 = tmp1 - tmp2;
|
|
} else {
|
|
/* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
|
|
tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
|
|
tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
|
|
}
|
|
}
|
|
|
|
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
|
|
|
|
dataptr[DCTSTRIDE*0] = tmp10 >> (CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSTRIDE*1] = tmp11 >> (CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSTRIDE*2] = tmp12 >> (CONST_BITS+PASS1_BITS+3);
|
|
dataptr[DCTSTRIDE*3] = tmp13 >> (CONST_BITS+PASS1_BITS+3);
|
|
|
|
dataptr++; /* advance pointer to next column */
|
|
}
|
|
}
|
|
|
|
void j_rev_dct2(DCTBLOCK data){
|
|
int d00, d01, d10, d11;
|
|
|
|
data[0] += 4;
|
|
d00 = data[0+0*DCTSTRIDE] + data[1+0*DCTSTRIDE];
|
|
d01 = data[0+0*DCTSTRIDE] - data[1+0*DCTSTRIDE];
|
|
d10 = data[0+1*DCTSTRIDE] + data[1+1*DCTSTRIDE];
|
|
d11 = data[0+1*DCTSTRIDE] - data[1+1*DCTSTRIDE];
|
|
|
|
data[0+0*DCTSTRIDE]= (d00 + d10)>>3;
|
|
data[1+0*DCTSTRIDE]= (d01 + d11)>>3;
|
|
data[0+1*DCTSTRIDE]= (d00 - d10)>>3;
|
|
data[1+1*DCTSTRIDE]= (d01 - d11)>>3;
|
|
}
|
|
|
|
void j_rev_dct1(DCTBLOCK data){
|
|
data[0] = (data[0] + 4)>>3;
|
|
}
|
|
|
|
#undef FIX
|
|
#undef CONST_BITS
|