| /* |
| * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder |
| * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> |
| * |
| * 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 |
| */ |
| |
| /** |
| * @file |
| * Context Adaptive Binary Arithmetic Coder. |
| */ |
| |
| #include <string.h> |
| |
| #include "libavutil/common.h" |
| #include "libavutil/timer.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_encoder(CABACContext *c, uint8_t *buf, int buf_size){ |
| init_put_bits(&c->pb, buf, buf_size); |
| |
| c->low= 0; |
| c->range= 0x1FE; |
| c->outstanding_count= 0; |
| c->pb.bit_left++; //avoids firstBitFlag |
| } |
| |
| /** |
| * |
| * @param buf_size size of buf in bits |
| */ |
| int 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; |
| // Keep our fetches on a 2-byte boundary as this should avoid ever having to |
| // do unaligned loads if the compiler (or asm) optimises the double byte |
| // load into a single instruction |
| if(((uintptr_t)c->bytestream & 1) == 0) { |
| c->low += (1 << 9); |
| } |
| else { |
| c->low += ((*c->bytestream++) << 2) + 2; |
| } |
| #else |
| c->low = (*c->bytestream++)<<10; |
| c->low+= ((*c->bytestream++)<<2) + 2; |
| #endif |
| c->range= 0x1FE; |
| if ((c->range<<(CABAC_BITS+1)) < c->low) |
| return AVERROR_INVALIDDATA; |
| return 0; |
| } |
