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avcodec/cbrt_tablegen: Deduplicate common code

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Namely the part that creates a temporary LUT.

Reviewed-by: Zhao Zhili <quinkblack@foxmail.com>
Reviewed-by: Lynne <dev@lynne.ee>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt
2025-09-03 02:53:46 +02:00
parent 9bacefc41e
commit 2611874a50
5 changed files with 71 additions and 30 deletions
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6
libavcodec/Makefile
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@@ -195,11 +195,13 @@ OBJS-$(CONFIG_A64MULTI5_ENCODER) += a64multienc.o elbg.o
OBJS-$(CONFIG_AAC_DECODER) += aactab.o \
aacsbr.o aacps_common.o aacps_float.o \
kbdwin.o \
sbrdsp.o aacpsdsp_float.o cbrt_data.o
sbrdsp.o aacpsdsp_float.o cbrt_data.o \
$(if $(!CONFIG_HARDCODED_TABLES), cbrt_tablegen_common.o)
OBJS-$(CONFIG_AAC_FIXED_DECODER) += aactab.o \
aacsbr_fixed.o aacps_common.o aacps_fixed.o \
kbdwin.o \
sbrdsp_fixed.o aacpsdsp_fixed.o cbrt_data_fixed.o
sbrdsp_fixed.o aacpsdsp_fixed.o cbrt_data_fixed.o \
$(if $(!CONFIG_HARDCODED_TABLES), cbrt_tablegen_common.o)
OBJS-$(CONFIG_AAC_ENCODER) += aacenc.o aaccoder.o aacenctab.o \
aacpsy.o aactab.o \
aacenc_is.o \

5
libavcodec/cbrt_data.h
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@@ -40,6 +40,11 @@ void ff_cbrt_tableinit(void);
void ff_cbrt_tableinit_fixed(void);
#define TMP_LUT_SIZE (LUT_SIZE / 2)
/**
* Creates a LUT (of doubles) for the powers of
* the odd integers: tmp_lut[idx] will be set to (2 * idx + 1)^{4/3}.
*/
void ff_cbrt_dbl_tableinit(double tmp_lut[TMP_LUT_SIZE]);
extern union CBRT {
uint32_t cbrt_tab[LUT_SIZE];

29
libavcodec/cbrt_tablegen.h
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@@ -46,34 +46,7 @@ av_cold void AAC_RENAME(ff_cbrt_tableinit)(void)
"unexpected sizeofs");
// We reuse ff_cbrt_tab_internal.tmp as a LUT (of doubles) for the roots
// of the odd integers: tmp[idx] contains (2 * idx + 1)^{4/3}.
for (int idx = 0; idx < TMP_LUT_SIZE; ++idx)
AAC_RENAME(ff_cbrt_tab_internal).tmp[idx] = 1;
/* have to take care of non-squarefree numbers; notice that sqrt(LUT_SIZE) = 90;
* idx == 44 corresponds to 89. */
for (int idx = 1; idx < 45; ++idx) {
if (AAC_RENAME(ff_cbrt_tab_internal).tmp[idx] == 1) {
int i = 2 * idx + 1;
double cbrt_val = i * cbrt(i);
for (int k = i; k < LUT_SIZE; k *= i) {
// We only have to handle k, 3 * k, 5 * k,...,
// because only these are odd. The corresponding indices are
// k >> 1, (k >> 1) + k, (k >> 1) + 2 * k,...
for (int idx2 = k >> 1; idx2 < TMP_LUT_SIZE; idx2 += k)
AAC_RENAME(ff_cbrt_tab_internal).tmp[idx2] *= cbrt_val;
}
}
}
for (int idx = 45; idx < TMP_LUT_SIZE; ++idx) {
if (AAC_RENAME(ff_cbrt_tab_internal).tmp[idx] == 1) {
int i = 2 * idx + 1;
double cbrt_val = i * cbrt(i);
for (int idx2 = idx; idx2 < TMP_LUT_SIZE; idx2 += i)
AAC_RENAME(ff_cbrt_tab_internal).tmp[idx2] *= cbrt_val;
}
}
ff_cbrt_dbl_tableinit(AAC_RENAME(ff_cbrt_tab_internal).tmp);
double cbrt_2 = 2 * cbrt(2);
for (int idx = TMP_LUT_SIZE - 1; idx >= 0; --idx) {

60
libavcodec/cbrt_tablegen_common.c Normal file
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@@ -0,0 +1,60 @@
/*
* Common code for AAC cube-root table
*
* Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <math.h>
#include "cbrt_data.h"
#include "libavutil/attributes.h"
#ifdef HAVE_AV_CONFIG_H // Only include libm.h when building for the target, not the host
#include "libavutil/libm.h"
#endif
av_cold void ff_cbrt_dbl_tableinit(double tmp_lut[TMP_LUT_SIZE])
{
for (int idx = 0; idx < TMP_LUT_SIZE; ++idx)
tmp_lut[idx] = 1;
/* have to take care of non-squarefree numbers; notice that sqrt(LUT_SIZE) = 90;
* idx == 44 corresponds to 89. */
for (int idx = 1; idx < 45; ++idx) {
if (tmp_lut[idx] == 1) {
int i = 2 * idx + 1;
double cbrt_val = i * cbrt(i);
for (int k = i; k < LUT_SIZE; k *= i) {
// We only have to handle k, 3 * k, 5 * k,...,
// because only these are odd. The corresponding indices are
// k >> 1, (k >> 1) + k, (k >> 1) + 2 * k,...
for (int idx2 = k >> 1; idx2 < TMP_LUT_SIZE; idx2 += k)
tmp_lut[idx2] *= cbrt_val;
}
}
}
for (int idx = 45; idx < TMP_LUT_SIZE; ++idx) {
if (tmp_lut[idx] == 1) {
int i = 2 * idx + 1;
double cbrt_val = i * cbrt(i);
for (int idx2 = idx; idx2 < TMP_LUT_SIZE; idx2 += i)
tmp_lut[idx2] *= cbrt_val;
}
}
}

1
libavcodec/cbrt_tablegen_template.c
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@@ -24,6 +24,7 @@
#define BUILD_TABLES 1
#include "libavutil/tablegen.h"
#include "cbrt_tablegen.h"
#include "cbrt_tablegen_common.c"
#include "tableprint.h"
int main(void)