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![Christophe GISQUET](/assets/img/avatar_default.png)
When decoding coefficients, detect whether the block is DC-only, and take advantage of this knowledge to perform DC-only inverse transform. This is achieved by: - first, changing the 108x4 element modulo_three_table into a 108 element table (kind of base4), and accessing each value using mask and shifts. - then, checking low bits for 0 (as they represent the presence of higher frequency coefficients) Also provide x86 SIMD code for the DC-only inverse transform. Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>
127 lines
4.2 KiB
C
127 lines
4.2 KiB
C
/*
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* RealVideo 4 decoder
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* copyright (c) 2007 Konstantin Shishkov
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*
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* This file is part of Libav.
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*
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* Libav 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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* Libav 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 Libav; 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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/**
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* @file
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* miscellaneous RV30/40 tables
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*/
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#ifndef AVCODEC_RV34DATA_H
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#define AVCODEC_RV34DATA_H
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#include <stdint.h>
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/**
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* number of ones in nibble minus one
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*/
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static const uint8_t rv34_count_ones[16] = {
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0, 0, 0, 1, 0, 1, 1, 2, 0, 1, 1, 2, 1, 2, 2, 3
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};
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/**
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* values used to reconstruct coded block pattern
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*/
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static const uint8_t rv34_cbp_code[16] = {
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0x00, 0x20, 0x10, 0x30, 0x02, 0x22, 0x12, 0x32,
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0x01, 0x21, 0x11, 0x31, 0x03, 0x23, 0x13, 0x33
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};
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/**
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* precalculated results of division by three and modulo three for values 0-107
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*
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* A lot of four-tuples in RV40 are represented as c0*27+c1*9+c2*3+c3.
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* This table allows conversion from a value back to a vector.
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*/
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static const uint8_t modulo_three_table[108] = {
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0x00, 0x01, 0x02, 0x04, 0x05, 0x06, 0x08, 0x09, 0x0A,
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0x10, 0x11, 0x12, 0x14, 0x15, 0x16, 0x18, 0x19, 0x1A,
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0x20, 0x21, 0x22, 0x24, 0x25, 0x26, 0x28, 0x29, 0x2A,
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0x40, 0x41, 0x42, 0x44, 0x45, 0x46, 0x48, 0x49, 0x4A,
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0x50, 0x51, 0x52, 0x54, 0x55, 0x56, 0x58, 0x59, 0x5A,
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0x60, 0x61, 0x62, 0x64, 0x65, 0x66, 0x68, 0x69, 0x6A,
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0x80, 0x81, 0x82, 0x84, 0x85, 0x86, 0x88, 0x89, 0x8A,
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0x90, 0x91, 0x92, 0x94, 0x95, 0x96, 0x98, 0x99, 0x9A,
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0xA0, 0xA1, 0xA2, 0xA4, 0xA5, 0xA6, 0xA8, 0xA9, 0xAA,
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0xC0, 0xC1, 0xC2, 0xC4, 0xC5, 0xC6, 0xC8, 0xC9, 0xCA,
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0xD0, 0xD1, 0xD2, 0xD4, 0xD5, 0xD6, 0xD8, 0xD9, 0xDA,
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0xE0, 0xE1, 0xE2, 0xE4, 0xE5, 0xE6, 0xE8, 0xE9, 0xEA,
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};
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/**
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* quantizer values used for AC and DC coefficients in chroma blocks
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*/
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static const uint8_t rv34_chroma_quant[2][32] = {
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{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
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16, 17, 17, 18, 19, 20, 20, 21, 22, 22, 23, 23, 24, 24, 25, 25 },
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{ 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
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14, 15, 15, 16, 17, 18, 18, 19, 20, 20, 21, 21, 22, 22, 23, 23 }
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};
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/**
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* This table is used for dequantizing.
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*/
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static const uint16_t rv34_qscale_tab[32] = {
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60, 67, 76, 85, 96, 108, 121, 136,
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152, 171, 192, 216, 242, 272, 305, 341,
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383, 432, 481, 544, 606, 683, 767, 854,
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963, 1074, 1212, 1392, 1566, 1708, 1978, 2211
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};
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/**
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* tables used to translate a quantizer value into a VLC set for decoding
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* The first table is used for intraframes.
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*/
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static const uint8_t rv34_quant_to_vlc_set[2][31] = {
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{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,
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2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 0 },
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{ 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3,
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3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6 },
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};
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/**
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* table for obtaining the quantizer difference
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* @todo Use with modified_quant_tab from h263data.h.
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*/
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static const uint8_t rv34_dquant_tab[2][32]={
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// 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
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{
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0, 3, 1, 2, 3, 4, 5, 6, 7, 8, 9, 9,10,11,12,13,14,15,16,17,18,18,19,20,21,22,23,24,25,26,27,28
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},{
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0, 2, 3, 4, 5, 6, 7, 8, 9,10,11,13,14,15,16,17,18,19,20,21,22,24,25,26,27,28,29,30,31,31,31,26
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}
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};
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/**
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* maximum number of macroblocks for each of the possible slice offset sizes
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* @todo This is the same as ff_mba_max, maybe use it instead.
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*/
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static const uint16_t rv34_mb_max_sizes[6] = { 0x2F, 0x62, 0x18B, 0x62F, 0x18BF, 0x23FF };
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/**
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* bits needed to code the slice offset for the given size
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* @todo This is the same as ff_mba_length, maybe use it instead.
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*/
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static const uint8_t rv34_mb_bits_sizes[6] = { 6, 7, 9, 11, 13, 14 };
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#endif /* AVCODEC_RV34DATA_H */
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