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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 14:29:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 14:29:10 +0000
commit2aa4a82499d4becd2284cdb482213d541b8804dd (patch)
treeb80bf8bf13c3766139fbacc530efd0dd9d54394c /media/ffvpx/libavcodec/jfdctfst.c
parentInitial commit. (diff)
downloadfirefox-upstream.tar.xz
firefox-upstream.zip
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'media/ffvpx/libavcodec/jfdctfst.c')
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diff --git a/media/ffvpx/libavcodec/jfdctfst.c b/media/ffvpx/libavcodec/jfdctfst.c
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+/*
+ * This file is part of the Independent JPEG Group's software.
+ *
+ * The authors make NO WARRANTY or representation, either express or implied,
+ * with respect to this software, its quality, accuracy, merchantability, or
+ * fitness for a particular purpose. This software is provided "AS IS", and
+ * you, its user, assume the entire risk as to its quality and accuracy.
+ *
+ * This software is copyright (C) 1994-1996, Thomas G. Lane.
+ * All Rights Reserved except as specified below.
+ *
+ * Permission is hereby granted to use, copy, modify, and distribute this
+ * software (or portions thereof) for any purpose, without fee, subject to
+ * these conditions:
+ * (1) If any part of the source code for this software is distributed, then
+ * this README file must be included, with this copyright and no-warranty
+ * notice unaltered; and any additions, deletions, or changes to the original
+ * files must be clearly indicated in accompanying documentation.
+ * (2) If only executable code is distributed, then the accompanying
+ * documentation must state that "this software is based in part on the work
+ * of the Independent JPEG Group".
+ * (3) Permission for use of this software is granted only if the user accepts
+ * full responsibility for any undesirable consequences; the authors accept
+ * NO LIABILITY for damages of any kind.
+ *
+ * These conditions apply to any software derived from or based on the IJG
+ * code, not just to the unmodified library. If you use our work, you ought
+ * to acknowledge us.
+ *
+ * Permission is NOT granted for the use of any IJG author's name or company
+ * name in advertising or publicity relating to this software or products
+ * derived from it. This software may be referred to only as "the Independent
+ * JPEG Group's software".
+ *
+ * We specifically permit and encourage the use of this software as the basis
+ * of commercial products, provided that all warranty or liability claims are
+ * assumed by the product vendor.
+ *
+ * This file contains a fast, not so accurate integer implementation of the
+ * forward DCT (Discrete Cosine Transform).
+ *
+ * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
+ * on each column. Direct algorithms are also available, but they are
+ * much more complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README). The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs. These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries. The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with fixed-point math,
+ * accuracy is lost due to imprecise representation of the scaled
+ * quantization values. The smaller the quantization table entry, the less
+ * precise the scaled value, so this implementation does worse with high-
+ * quality-setting files than with low-quality ones.
+ */
+
+/**
+ * @file
+ * Independent JPEG Group's fast AAN dct.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "libavutil/common.h"
+#include "dct.h"
+
+#define DCTSIZE 8
+#define GLOBAL(x) x
+#define RIGHT_SHIFT(x, n) ((x) >> (n))
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+ Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+#endif
+
+
+/* Scaling decisions are generally the same as in the LL&M algorithm;
+ * see jfdctint.c for more details. However, we choose to descale
+ * (right shift) multiplication products as soon as they are formed,
+ * rather than carrying additional fractional bits into subsequent additions.
+ * This compromises accuracy slightly, but it lets us save a few shifts.
+ * More importantly, 16-bit arithmetic is then adequate (for 8-bit samples)
+ * everywhere except in the multiplications proper; this saves a good deal
+ * of work on 16-bit-int machines.
+ *
+ * Again to save a few shifts, the intermediate results between pass 1 and
+ * pass 2 are not upscaled, but are represented only to integral precision.
+ *
+ * A final compromise is to represent the multiplicative constants to only
+ * 8 fractional bits, rather than 13. This saves some shifting work on some
+ * machines, and may also reduce the cost of multiplication (since there
+ * are fewer one-bits in the constants).
+ */
+
+#define CONST_BITS 8
+
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 8
+#define FIX_0_382683433 ((int32_t) 98) /* FIX(0.382683433) */
+#define FIX_0_541196100 ((int32_t) 139) /* FIX(0.541196100) */
+#define FIX_0_707106781 ((int32_t) 181) /* FIX(0.707106781) */
+#define FIX_1_306562965 ((int32_t) 334) /* FIX(1.306562965) */
+#else
+#define FIX_0_382683433 FIX(0.382683433)
+#define FIX_0_541196100 FIX(0.541196100)
+#define FIX_0_707106781 FIX(0.707106781)
+#define FIX_1_306562965 FIX(1.306562965)
+#endif
+
+
+/* We can gain a little more speed, with a further compromise in accuracy,
+ * by omitting the addition in a descaling shift. This yields an incorrectly
+ * rounded result half the time...
+ */
+
+#ifndef USE_ACCURATE_ROUNDING
+#undef DESCALE
+#define DESCALE(x,n) RIGHT_SHIFT(x, n)
+#endif
+
+
+/* Multiply a int16_t variable by an int32_t constant, and immediately
+ * descale to yield a int16_t result.
+ */
+
+#define MULTIPLY(var,const) ((int16_t) DESCALE((var) * (const), CONST_BITS))
+
+static av_always_inline void row_fdct(int16_t * data){
+ int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ int tmp10, tmp11, tmp12, tmp13;
+ int z1, z2, z3, z4, z5, z11, z13;
+ int16_t *dataptr;
+ int ctr;
+
+ /* Pass 1: process rows. */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[0] + dataptr[7];
+ tmp7 = dataptr[0] - dataptr[7];
+ tmp1 = dataptr[1] + dataptr[6];
+ tmp6 = dataptr[1] - dataptr[6];
+ tmp2 = dataptr[2] + dataptr[5];
+ tmp5 = dataptr[2] - dataptr[5];
+ tmp3 = dataptr[3] + dataptr[4];
+ tmp4 = dataptr[3] - dataptr[4];
+
+ /* Even part */
+
+ tmp10 = tmp0 + tmp3; /* phase 2 */
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ dataptr[0] = tmp10 + tmp11; /* phase 3 */
+ dataptr[4] = tmp10 - tmp11;
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_707106781); /* c4 */
+ dataptr[2] = tmp13 + z1; /* phase 5 */
+ dataptr[6] = tmp13 - z1;
+
+ /* Odd part */
+
+ tmp10 = tmp4 + tmp5; /* phase 2 */
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp6 + tmp7;
+
+ /* The rotator is modified from fig 4-8 to avoid extra negations. */
+ z5 = MULTIPLY(tmp10 - tmp12, FIX_0_382683433); /* c6 */
+ z2 = MULTIPLY(tmp10, FIX_0_541196100) + z5; /* c2-c6 */
+ z4 = MULTIPLY(tmp12, FIX_1_306562965) + z5; /* c2+c6 */
+ z3 = MULTIPLY(tmp11, FIX_0_707106781); /* c4 */
+
+ z11 = tmp7 + z3; /* phase 5 */
+ z13 = tmp7 - z3;
+
+ dataptr[5] = z13 + z2; /* phase 6 */
+ dataptr[3] = z13 - z2;
+ dataptr[1] = z11 + z4;
+ dataptr[7] = z11 - z4;
+
+ dataptr += DCTSIZE; /* advance pointer to next row */
+ }
+}
+
+/*
+ * Perform the forward DCT on one block of samples.
+ */
+
+GLOBAL(void)
+ff_fdct_ifast (int16_t * data)
+{
+ int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ int tmp10, tmp11, tmp12, tmp13;
+ int z1, z2, z3, z4, z5, z11, z13;
+ int16_t *dataptr;
+ int ctr;
+
+ row_fdct(data);
+
+ /* Pass 2: process columns. */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
+ tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
+ tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
+ tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
+ tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
+ tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
+ tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
+ tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
+
+ /* Even part */
+
+ tmp10 = tmp0 + tmp3; /* phase 2 */
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ dataptr[DCTSIZE*0] = tmp10 + tmp11; /* phase 3 */
+ dataptr[DCTSIZE*4] = tmp10 - tmp11;
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_707106781); /* c4 */
+ dataptr[DCTSIZE*2] = tmp13 + z1; /* phase 5 */
+ dataptr[DCTSIZE*6] = tmp13 - z1;
+
+ /* Odd part */
+
+ tmp10 = tmp4 + tmp5; /* phase 2 */
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp6 + tmp7;
+
+ /* The rotator is modified from fig 4-8 to avoid extra negations. */
+ z5 = MULTIPLY(tmp10 - tmp12, FIX_0_382683433); /* c6 */
+ z2 = MULTIPLY(tmp10, FIX_0_541196100) + z5; /* c2-c6 */
+ z4 = MULTIPLY(tmp12, FIX_1_306562965) + z5; /* c2+c6 */
+ z3 = MULTIPLY(tmp11, FIX_0_707106781); /* c4 */
+
+ z11 = tmp7 + z3; /* phase 5 */
+ z13 = tmp7 - z3;
+
+ dataptr[DCTSIZE*5] = z13 + z2; /* phase 6 */
+ dataptr[DCTSIZE*3] = z13 - z2;
+ dataptr[DCTSIZE*1] = z11 + z4;
+ dataptr[DCTSIZE*7] = z11 - z4;
+
+ dataptr++; /* advance pointer to next column */
+ }
+}
+
+/*
+ * Perform the forward 2-4-8 DCT on one block of samples.
+ */
+
+GLOBAL(void)
+ff_fdct_ifast248 (int16_t * data)
+{
+ int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ int tmp10, tmp11, tmp12, tmp13;
+ int z1;
+ int16_t *dataptr;
+ int ctr;
+
+ row_fdct(data);
+
+ /* Pass 2: process columns. */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*1];
+ tmp1 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*3];
+ tmp2 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*5];
+ tmp3 = dataptr[DCTSIZE*6] + dataptr[DCTSIZE*7];
+ tmp4 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*1];
+ tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*3];
+ tmp6 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*5];
+ tmp7 = dataptr[DCTSIZE*6] - dataptr[DCTSIZE*7];
+
+ /* Even part */
+
+ tmp10 = tmp0 + tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+ tmp13 = tmp0 - tmp3;
+
+ dataptr[DCTSIZE*0] = tmp10 + tmp11;
+ dataptr[DCTSIZE*4] = tmp10 - tmp11;
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_707106781);
+ dataptr[DCTSIZE*2] = tmp13 + z1;
+ dataptr[DCTSIZE*6] = tmp13 - z1;
+
+ tmp10 = tmp4 + tmp7;
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp5 - tmp6;
+ tmp13 = tmp4 - tmp7;
+
+ dataptr[DCTSIZE*1] = tmp10 + tmp11;
+ dataptr[DCTSIZE*5] = tmp10 - tmp11;
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_707106781);
+ dataptr[DCTSIZE*3] = tmp13 + z1;
+ dataptr[DCTSIZE*7] = tmp13 - z1;
+
+ dataptr++; /* advance pointer to next column */
+ }
+}
+
+
+#undef GLOBAL
+#undef CONST_BITS
+#undef DESCALE
+#undef FIX_0_541196100
+#undef FIX_1_306562965