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- /*
- * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
- * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
- *
- * This file is part of Libav.
- *
- * Libav 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.
- *
- * Libav 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 Libav; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
- /**
- * @file
- * Context Adaptive Binary Arithmetic Coder.
- */
-
- #include <string.h>
-
- #include "libavutil/common.h"
-
- #include "cabac.h"
- #include "cabac_functions.h"
-
- const uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63] = {
- 9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5,
- 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
- 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
- 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
- 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
- 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
- 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
- 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
- 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
- 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
- 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
- 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
- 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
- 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
- // LPS range
- -128, -128, -128, -128, -128, -128, 123, 123,
- 116, 116, 111, 111, 105, 105, 100, 100,
- 95, 95, 90, 90, 85, 85, 81, 81,
- 77, 77, 73, 73, 69, 69, 66, 66,
- 62, 62, 59, 59, 56, 56, 53, 53,
- 51, 51, 48, 48, 46, 46, 43, 43,
- 41, 41, 39, 39, 37, 37, 35, 35,
- 33, 33, 32, 32, 30, 30, 29, 29,
- 27, 27, 26, 26, 24, 24, 23, 23,
- 22, 22, 21, 21, 20, 20, 19, 19,
- 18, 18, 17, 17, 16, 16, 15, 15,
- 14, 14, 14, 14, 13, 13, 12, 12,
- 12, 12, 11, 11, 11, 11, 10, 10,
- 10, 10, 9, 9, 9, 9, 8, 8,
- 8, 8, 7, 7, 7, 7, 7, 7,
- 6, 6, 6, 6, 6, 6, 2, 2,
- -80, -80, -89, -89, -98, -98, -106, -106,
- -114, -114, -121, -121, -128, -128, 122, 122,
- 116, 116, 110, 110, 104, 104, 99, 99,
- 94, 94, 89, 89, 85, 85, 80, 80,
- 76, 76, 72, 72, 69, 69, 65, 65,
- 62, 62, 59, 59, 56, 56, 53, 53,
- 50, 50, 48, 48, 45, 45, 43, 43,
- 41, 41, 39, 39, 37, 37, 35, 35,
- 33, 33, 31, 31, 30, 30, 28, 28,
- 27, 27, 26, 26, 24, 24, 23, 23,
- 22, 22, 21, 21, 20, 20, 19, 19,
- 18, 18, 17, 17, 16, 16, 15, 15,
- 14, 14, 14, 14, 13, 13, 12, 12,
- 12, 12, 11, 11, 11, 11, 10, 10,
- 9, 9, 9, 9, 9, 9, 8, 8,
- 8, 8, 7, 7, 7, 7, 2, 2,
- -48, -48, -59, -59, -69, -69, -78, -78,
- -87, -87, -96, -96, -104, -104, -112, -112,
- -119, -119, -126, -126, 123, 123, 117, 117,
- 111, 111, 105, 105, 100, 100, 95, 95,
- 90, 90, 86, 86, 81, 81, 77, 77,
- 73, 73, 69, 69, 66, 66, 63, 63,
- 59, 59, 56, 56, 54, 54, 51, 51,
- 48, 48, 46, 46, 43, 43, 41, 41,
- 39, 39, 37, 37, 35, 35, 33, 33,
- 32, 32, 30, 30, 29, 29, 27, 27,
- 26, 26, 25, 25, 23, 23, 22, 22,
- 21, 21, 20, 20, 19, 19, 18, 18,
- 17, 17, 16, 16, 15, 15, 15, 15,
- 14, 14, 13, 13, 12, 12, 12, 12,
- 11, 11, 11, 11, 10, 10, 10, 10,
- 9, 9, 9, 9, 8, 8, 2, 2,
- -16, -16, -29, -29, -40, -40, -51, -51,
- -61, -61, -71, -71, -81, -81, -90, -90,
- -98, -98, -106, -106, -114, -114, -121, -121,
- -128, -128, 122, 122, 116, 116, 110, 110,
- 104, 104, 99, 99, 94, 94, 89, 89,
- 85, 85, 80, 80, 76, 76, 72, 72,
- 69, 69, 65, 65, 62, 62, 59, 59,
- 56, 56, 53, 53, 50, 50, 48, 48,
- 45, 45, 43, 43, 41, 41, 39, 39,
- 37, 37, 35, 35, 33, 33, 31, 31,
- 30, 30, 28, 28, 27, 27, 25, 25,
- 24, 24, 23, 23, 22, 22, 21, 21,
- 20, 20, 19, 19, 18, 18, 17, 17,
- 16, 16, 15, 15, 14, 14, 14, 14,
- 13, 13, 12, 12, 12, 12, 11, 11,
- 11, 11, 10, 10, 9, 9, 2, 2,
- // mlps state
- 127, 126, 77, 76, 77, 76, 75, 74,
- 75, 74, 75, 74, 73, 72, 73, 72,
- 73, 72, 71, 70, 71, 70, 71, 70,
- 69, 68, 69, 68, 67, 66, 67, 66,
- 67, 66, 65, 64, 65, 64, 63, 62,
- 61, 60, 61, 60, 61, 60, 59, 58,
- 59, 58, 57, 56, 55, 54, 55, 54,
- 53, 52, 53, 52, 51, 50, 49, 48,
- 49, 48, 47, 46, 45, 44, 45, 44,
- 43, 42, 43, 42, 39, 38, 39, 38,
- 37, 36, 37, 36, 33, 32, 33, 32,
- 31, 30, 31, 30, 27, 26, 27, 26,
- 25, 24, 23, 22, 23, 22, 19, 18,
- 19, 18, 17, 16, 15, 14, 13, 12,
- 11, 10, 9, 8, 9, 8, 5, 4,
- 5, 4, 3, 2, 1, 0, 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, 32, 33,
- 34, 35, 36, 37, 38, 39, 40, 41,
- 42, 43, 44, 45, 46, 47, 48, 49,
- 50, 51, 52, 53, 54, 55, 56, 57,
- 58, 59, 60, 61, 62, 63, 64, 65,
- 66, 67, 68, 69, 70, 71, 72, 73,
- 74, 75, 76, 77, 78, 79, 80, 81,
- 82, 83, 84, 85, 86, 87, 88, 89,
- 90, 91, 92, 93, 94, 95, 96, 97,
- 98, 99, 100, 101, 102, 103, 104, 105,
- 106, 107, 108, 109, 110, 111, 112, 113,
- 114, 115, 116, 117, 118, 119, 120, 121,
- 122, 123, 124, 125, 124, 125, 126, 127,
- // last_coeff_flag_offset_8x8
- 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
- 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
- 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8
- };
-
- /**
- * @param buf_size size of buf in bits
- */
- void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){
- c->bytestream_start=
- c->bytestream= buf;
- c->bytestream_end= buf + buf_size;
-
- #if CABAC_BITS == 16
- c->low = (*c->bytestream++)<<18;
- c->low+= (*c->bytestream++)<<10;
- #else
- c->low = (*c->bytestream++)<<10;
- #endif
- c->low+= ((*c->bytestream++)<<2) + 2;
- c->range= 0x1FE;
- }
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