2 * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * Context Adaptive Binary Arithmetic Coder.
30 #include "bitstream.h"
33 static const uint8_t lps_range
[64][4]= {
34 {128,176,208,240}, {128,167,197,227}, {128,158,187,216}, {123,150,178,205},
35 {116,142,169,195}, {111,135,160,185}, {105,128,152,175}, {100,122,144,166},
36 { 95,116,137,158}, { 90,110,130,150}, { 85,104,123,142}, { 81, 99,117,135},
37 { 77, 94,111,128}, { 73, 89,105,122}, { 69, 85,100,116}, { 66, 80, 95,110},
38 { 62, 76, 90,104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89},
39 { 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72},
40 { 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59},
41 { 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48},
42 { 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39},
43 { 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31},
44 { 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25},
45 { 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21},
46 { 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17},
47 { 10, 12, 14, 16}, { 9, 11, 13, 15}, { 9, 11, 12, 14}, { 8, 10, 12, 14},
48 { 8, 9, 11, 13}, { 7, 9, 11, 12}, { 7, 9, 10, 12}, { 7, 8, 10, 11},
49 { 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2},
52 uint8_t ff_h264_mlps_state
[4*64];
53 uint8_t ff_h264_lps_range
[4*2*64];
54 uint8_t ff_h264_lps_state
[2*64];
55 uint8_t ff_h264_mps_state
[2*64];
57 static const uint8_t mps_state
[64]= {
58 1, 2, 3, 4, 5, 6, 7, 8,
59 9,10,11,12,13,14,15,16,
60 17,18,19,20,21,22,23,24,
61 25,26,27,28,29,30,31,32,
62 33,34,35,36,37,38,39,40,
63 41,42,43,44,45,46,47,48,
64 49,50,51,52,53,54,55,56,
65 57,58,59,60,61,62,62,63,
68 static const uint8_t lps_state
[64]= {
69 0, 0, 1, 2, 2, 4, 4, 5,
70 6, 7, 8, 9, 9,11,11,12,
71 13,13,15,15,16,16,18,18,
72 19,19,21,21,22,22,23,24,
73 24,25,26,26,27,27,28,29,
74 29,30,30,30,31,32,32,33,
75 33,33,34,34,35,35,35,36,
76 36,36,37,37,37,38,38,63,
79 const uint8_t ff_h264_norm_shift_old
[128]= {
80 7,6,5,5,4,4,4,4,3,3,3,3,3,3,3,3,
81 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
82 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
83 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
84 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
85 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
86 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
87 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
90 const uint8_t ff_h264_norm_shift
[512]= {
91 9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5,
92 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
93 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
94 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
95 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
96 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
97 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
98 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
99 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,
100 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,
101 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,
102 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,
103 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
104 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
105 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
106 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
107 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
108 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
109 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
110 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
115 * @param buf_size size of buf in bits
117 void ff_init_cabac_encoder(CABACContext
*c
, uint8_t *buf
, int buf_size
){
118 init_put_bits(&c
->pb
, buf
, buf_size
);
122 c
->outstanding_count
= 0;
127 c
->pb
.bit_left
++; //avoids firstBitFlag
132 * @param buf_size size of buf in bits
134 void ff_init_cabac_decoder(CABACContext
*c
, const uint8_t *buf
, int buf_size
){
137 c
->bytestream_end
= buf
+ buf_size
;
140 c
->low
= (*c
->bytestream
++)<<18;
141 c
->low
+= (*c
->bytestream
++)<<10;
143 c
->low
= (*c
->bytestream
++)<<10;
145 c
->low
+= ((*c
->bytestream
++)<<2) + 2;
149 void ff_init_cabac_states(CABACContext
*c
){
153 for(j
=0; j
<4; j
++){ //FIXME check if this is worth the 1 shift we save
154 ff_h264_lps_range
[j
*2*64+2*i
+0]=
155 ff_h264_lps_range
[j
*2*64+2*i
+1]= lps_range
[i
][j
];
158 ff_h264_mlps_state
[128+2*i
+0]=
159 ff_h264_mps_state
[2*i
+0]= 2*mps_state
[i
]+0;
160 ff_h264_mlps_state
[128+2*i
+1]=
161 ff_h264_mps_state
[2*i
+1]= 2*mps_state
[i
]+1;
164 #ifdef BRANCHLESS_CABAC_DECODER
165 ff_h264_mlps_state
[128-2*i
-1]= 2*lps_state
[i
]+0;
166 ff_h264_mlps_state
[128-2*i
-2]= 2*lps_state
[i
]+1;
168 ff_h264_mlps_state
[128-2*i
-1]= 1;
169 ff_h264_mlps_state
[128-2*i
-2]= 0;
171 ff_h264_lps_state
[2*i
+0]= 2*lps_state
[i
]+0;
172 ff_h264_lps_state
[2*i
+1]= 2*lps_state
[i
]+1;
174 ff_h264_lps_state
[2*i
+0]= 1;
175 ff_h264_lps_state
[2*i
+1]= 0;
192 uint8_t state
[10]= {0};
194 ff_init_cabac_encoder(&c
, b
, SIZE
);
195 ff_init_cabac_states(&c
, ff_h264_lps_range
, ff_h264_mps_state
, ff_h264_lps_state
, 64);
197 for(i
=0; i
<SIZE
; i
++){
201 for(i
=0; i
<SIZE
; i
++){
203 put_cabac_bypass(&c
, r
[i
]&1);
204 STOP_TIMER("put_cabac_bypass")
207 for(i
=0; i
<SIZE
; i
++){
209 put_cabac(&c
, state
, r
[i
]&1);
210 STOP_TIMER("put_cabac")
213 for(i
=0; i
<SIZE
; i
++){
215 put_cabac_u(&c
, state
, r
[i
], 6, 3, i
&1);
216 STOP_TIMER("put_cabac_u")
219 for(i
=0; i
<SIZE
; i
++){
221 put_cabac_ueg(&c
, state
, r
[i
], 3, 0, 1, 2);
222 STOP_TIMER("put_cabac_ueg")
225 put_cabac_terminate(&c
, 1);
227 ff_init_cabac_decoder(&c
, b
, SIZE
);
229 memset(state
, 0, sizeof(state
));
231 for(i
=0; i
<SIZE
; i
++){
233 if( (r
[i
]&1) != get_cabac_bypass(&c
) )
234 av_log(NULL
, AV_LOG_ERROR
, "CABAC bypass failure at %d\n", i
);
235 STOP_TIMER("get_cabac_bypass")
238 for(i
=0; i
<SIZE
; i
++){
240 if( (r
[i
]&1) != get_cabac(&c
, state
) )
241 av_log(NULL
, AV_LOG_ERROR
, "CABAC failure at %d\n", i
);
242 STOP_TIMER("get_cabac")
245 for(i
=0; i
<SIZE
; i
++){
247 if( r
[i
] != get_cabac_u(&c
, state
, (i
&1) ? 6 : 7, 3, i
&1) )
248 av_log(NULL
, AV_LOG_ERROR
, "CABAC unary (truncated) binarization failure at %d\n", i
);
249 STOP_TIMER("get_cabac_u")
252 for(i
=0; i
<SIZE
; i
++){
254 if( r
[i
] != get_cabac_ueg(&c
, state
, 3, 0, 1, 2))
255 av_log(NULL
, AV_LOG_ERROR
, "CABAC unary (truncated) binarization failure at %d\n", i
);
256 STOP_TIMER("get_cabac_ueg")
259 if(!get_cabac_terminate(&c
))
260 av_log(NULL
, AV_LOG_ERROR
, "where's the Terminator?\n");