1 /*
2 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "libavcodec/cabac.c"
22
23 #define SIZE 10240
24
25 #include "libavutil/lfg.h"
26 #include "libavcodec/avcodec.h"
27
put_cabac_bit(CABACContext * c,int b)28 static inline void put_cabac_bit(CABACContext *c, int b){
29 put_bits(&c->pb, 1, b);
30 for(;c->outstanding_count; c->outstanding_count--){
31 put_bits(&c->pb, 1, 1-b);
32 }
33 }
34
renorm_cabac_encoder(CABACContext * c)35 static inline void renorm_cabac_encoder(CABACContext *c){
36 while(c->range < 0x100){
37 //FIXME optimize
38 if(c->low<0x100){
39 put_cabac_bit(c, 0);
40 }else if(c->low<0x200){
41 c->outstanding_count++;
42 c->low -= 0x100;
43 }else{
44 put_cabac_bit(c, 1);
45 c->low -= 0x200;
46 }
47
48 c->range+= c->range;
49 c->low += c->low;
50 }
51 }
52
put_cabac(CABACContext * c,uint8_t * const state,int bit)53 static void put_cabac(CABACContext *c, uint8_t * const state, int bit){
54 int RangeLPS= ff_h264_lps_range[2*(c->range&0xC0) + *state];
55
56 if(bit == ((*state)&1)){
57 c->range -= RangeLPS;
58 *state = ff_h264_mlps_state[128 + *state];
59 }else{
60 c->low += c->range - RangeLPS;
61 c->range = RangeLPS;
62 *state= ff_h264_mlps_state[127 - *state];
63 }
64
65 renorm_cabac_encoder(c);
66 }
67
68 /**
69 * @param bit 0 -> write zero bit, !=0 write one bit
70 */
put_cabac_bypass(CABACContext * c,int bit)71 static void put_cabac_bypass(CABACContext *c, int bit){
72 c->low += c->low;
73
74 if(bit){
75 c->low += c->range;
76 }
77 //FIXME optimize
78 if(c->low<0x200){
79 put_cabac_bit(c, 0);
80 }else if(c->low<0x400){
81 c->outstanding_count++;
82 c->low -= 0x200;
83 }else{
84 put_cabac_bit(c, 1);
85 c->low -= 0x400;
86 }
87 }
88
89 /**
90 *
91 * @return the number of bytes written
92 */
put_cabac_terminate(CABACContext * c,int bit)93 static int put_cabac_terminate(CABACContext *c, int bit){
94 c->range -= 2;
95
96 if(!bit){
97 renorm_cabac_encoder(c);
98 }else{
99 c->low += c->range;
100 c->range= 2;
101
102 renorm_cabac_encoder(c);
103
104 av_assert0(c->low <= 0x1FF);
105 put_cabac_bit(c, c->low>>9);
106 put_bits(&c->pb, 2, ((c->low>>7)&3)|1);
107
108 flush_put_bits(&c->pb); //FIXME FIXME FIXME XXX wrong
109 }
110
111 return (put_bits_count(&c->pb)+7)>>3;
112 }
113
main(void)114 int main(void){
115 CABACContext c;
116 uint8_t b[9*SIZE];
117 uint8_t r[9*SIZE];
118 int i, ret = 0;
119 uint8_t state[10]= {0};
120 AVLFG prng;
121
122 av_lfg_init(&prng, 1);
123 ff_init_cabac_encoder(&c, b, SIZE);
124
125 for(i=0; i<SIZE; i++){
126 if(2*i<SIZE) r[i] = av_lfg_get(&prng) % 7;
127 else r[i] = (i>>8)&1;
128 }
129
130 for(i=0; i<SIZE; i++){
131 put_cabac_bypass(&c, r[i]&1);
132 }
133
134 for(i=0; i<SIZE; i++){
135 put_cabac(&c, state, r[i]&1);
136 }
137
138 i= put_cabac_terminate(&c, 1);
139 b[i++] = av_lfg_get(&prng);
140 b[i ] = av_lfg_get(&prng);
141
142 ff_init_cabac_decoder(&c, b, SIZE);
143
144 memset(state, 0, sizeof(state));
145
146 for(i=0; i<SIZE; i++){
147 if( (r[i]&1) != get_cabac_bypass(&c) ) {
148 av_log(NULL, AV_LOG_ERROR, "CABAC bypass failure at %d\n", i);
149 ret = 1;
150 }
151 }
152
153 for(i=0; i<SIZE; i++){
154 if( (r[i]&1) != get_cabac_noinline(&c, state) ) {
155 av_log(NULL, AV_LOG_ERROR, "CABAC failure at %d\n", i);
156 ret = 1;
157 }
158 }
159 if(!get_cabac_terminate(&c)) {
160 av_log(NULL, AV_LOG_ERROR, "where's the Terminator?\n");
161 ret = 1;
162 }
163
164 return ret;
165 }
166