mirror of
https://github.com/FFmpeg/FFmpeg.git
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Ayoub Nabil Boubagrat
5339fc6a51
cover band boundaries, partial ranges and exponent limits before changing the bit allocation code. Signed-off-by: Ayoub Nabil Boubagrat <237098474+ayoubnabil@users.noreply.github.com>
93 lines
3.3 KiB
C
93 lines
3.3 KiB
C
/*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg 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 GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <inttypes.h>
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#include <stdio.h>
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#include <string.h>
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#include "libavutil/crc.h"
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#include "libavutil/intreadwrite.h"
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#include "libavutil/lfg.h"
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#include "libavutil/macros.h"
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#include "libavcodec/ac3.h"
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#include "libavcodec/ac3dsp.h"
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#include "libavcodec/ac3tab.h"
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static uint32_t hash_int16(const AVCRC *crc, uint32_t hash,
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const int16_t *data, int count)
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{
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uint8_t bytes[2 * AC3_MAX_COEFS];
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for (int i = 0; i < count; i++)
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AV_WL16(bytes + 2 * i, data[i]);
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return av_crc(crc, hash, bytes, 2 * count);
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}
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int main(void)
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{
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static const int ends[] = { 7, 27, 28, 29, 37, 73, 133, 229, 253 };
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static const int offsets[] = { -960, -959, 0, 1024, 3132 };
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const AVCRC *crc = av_crc_get_table(AV_CRC_32_IEEE);
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int8_t exp[AC3_MAX_COEFS];
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int16_t psd[AC3_MAX_COEFS], band_psd[AC3_CRITICAL_BANDS];
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int16_t mask[AC3_CRITICAL_BANDS];
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uint8_t bap[AC3_MAX_COEFS];
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AC3DSPContext dsp;
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AVLFG lfg;
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ff_ac3dsp_init(&dsp);
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av_lfg_init(&lfg, 1);
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for (int i = 0; i < AC3_CRITICAL_BANDS; i++)
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mask[i] = av_lfg_get(&lfg) % 3073;
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for (int pattern = 0; pattern < 4; pattern++) {
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uint32_t psd_hash = 0, bap_hash = 0;
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for (int i = 0; i < AC3_MAX_COEFS; i++)
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exp[i] = pattern == 0 ? 0 : pattern == 1 ? 24 :
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pattern == 2 ? (i & 1) * 24 : av_lfg_get(&lfg) % 25;
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for (int start = 0; start < 253; start++) {
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for (int j = 0; j <= FF_ARRAY_ELEMS(ends); j++) {
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int end = j ? ends[j - 1] : start + 1;
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if (start >= end)
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continue;
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memset(psd, 0x5a, sizeof(psd));
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memset(band_psd, 0x5a, sizeof(band_psd));
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ff_ac3_bit_alloc_calc_psd(exp, start, end, psd, band_psd);
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psd_hash = hash_int16(crc, psd_hash, psd, AC3_MAX_COEFS);
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psd_hash = hash_int16(crc, psd_hash, band_psd, AC3_CRITICAL_BANDS);
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for (int floor = 0; floor < 8; floor++) {
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for (int k = 0; k < FF_ARRAY_ELEMS(offsets); k++) {
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memset(bap, 0x5a, sizeof(bap));
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dsp.bit_alloc_calc_bap(mask, psd, start, end,
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offsets[k], ff_ac3_floor_tab[floor],
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ff_ac3_bap_tab, bap);
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bap_hash = av_crc(crc, bap_hash, bap, sizeof(bap));
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}
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}
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}
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}
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printf("pattern %d: psd %08"PRIx32" bap %08"PRIx32"\n",
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pattern, psd_hash, bap_hash);
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}
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return 0;
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}
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