1 /*
2  * MQ-coder: structures, common and decoder functions
3  * Copyright (c) 2007 Kamil Nowosad
4  *
5  * This file is part of FFmpeg.
6  *
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.
11  *
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.
16  *
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
20  */
21 
22 #ifndef AVCODEC_MQC_H
23 #define AVCODEC_MQC_H
24 
25 /**
26  * MQ-coder
27  * @file
28  * @author Kamil Nowosad
29  */
30 
31 #include <stdint.h>
32 
33 #define MQC_CX_UNI 17
34 #define MQC_CX_RL  18
35 
36 extern const uint16_t ff_mqc_qe[2 * 47];
37 extern const uint8_t  ff_mqc_nlps[2 * 47];
38 extern const uint8_t  ff_mqc_nmps[2 * 47];
39 
40 typedef struct MqcState {
41     uint8_t *bp, *bpstart;
42     unsigned int a;
43     unsigned int c;
44     unsigned int ct;
45     uint8_t cx_states[19];
46     int raw;
47 } MqcState;
48 
49 /* encoder */
50 
51 /** initialize the encoder */
52 void ff_mqc_initenc(MqcState *mqc, uint8_t *bp);
53 
54 /** code bit d with context cx */
55 void ff_mqc_encode(MqcState *mqc, uint8_t *cxstate, int d);
56 
57 /** flush the encoder [returns number of bytes encoded] */
58 int ff_mqc_flush_to(MqcState *mqc, uint8_t *dst, int *dst_len);
59 
60 /* decoder */
61 
62 /**
63  * Initialize MQ-decoder.
64  * @param mqc   MQ decoder state
65  * @param bp    byte pointer
66  * @param raw   raw mode
67  * @param reset reset states
68  */
69 void ff_mqc_initdec(MqcState *mqc, uint8_t *bp, int raw, int reset);
70 
71 /**
72  * MQ decoder.
73  * @param mqc       MQ decoder state
74  * @param cxstate   Context
75  * @return          Decision (0 to 1)
76  */
77 int ff_mqc_decode(MqcState *mqc, uint8_t *cxstate);
78 
79 /* common */
80 
81 /**
82  * MQ-coder context initialisations.
83  * @param mqc       MQ-coder context
84  */
85 void ff_mqc_init_contexts(MqcState *mqc);
86 
87 #endif /* AVCODEC_MQC_H */
88