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
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
#include "mpeg3private.h"
#include "mpeg3protos.h"
#include <stdlib.h>
mpeg3_bits_t* mpeg3bits_new_stream(mpeg3_t *file, mpeg3_demuxer_t *demuxer)
{
mpeg3_bits_t *stream = (mpeg3_bits_t*)malloc(sizeof(mpeg3_bits_t));
stream->bfr = 0;
stream->bfr_size = 0;
stream->bit_number = 0;
stream->file = file;
stream->demuxer = demuxer;
stream->input_ptr = 0;
return stream;
}
int mpeg3bits_delete_stream(mpeg3_bits_t* stream)
{
free(stream);
return 0;
}
/* Fill a buffer. Only works if bit_number is on an 8 bit boundary */
int mpeg3bits_read_buffer(mpeg3_bits_t* stream, unsigned char *buffer, int bytes)
{
int result, i = 0;
while(stream->bit_number > 0)
{
stream->bit_number -= 8;
mpeg3demux_read_prev_char(stream->demuxer);
}
stream->bit_number = 0;
stream->bfr_size = 0;
stream->bfr = 0;
result = mpeg3demux_read_data(stream->demuxer, buffer, bytes);
return result;
}
/* For mp3 decompression use a pointer in a buffer for getbits. */
int mpeg3bits_use_ptr(mpeg3_bits_t* stream, unsigned char *buffer)
{
stream->bfr_size = stream->bit_number = 0;
stream->bfr = 0;
stream->input_ptr = buffer;
return 0;
}
/* Go back to using the demuxer for getbits in mp3. */
int mpeg3bits_use_demuxer(mpeg3_bits_t* stream)
{
if(stream->input_ptr)
{
stream->bfr_size = stream->bit_number = 0;
stream->input_ptr = 0;
stream->bfr = 0;
}
return 0;
}
/* Reconfigure for reverse operation */
/* Default is forward operation */
void mpeg3bits_start_reverse(mpeg3_bits_t* stream)
{
int i;
for(i = 0; i < stream->bfr_size; i += 8)
if(stream->input_ptr)
stream->input_ptr--;
else
mpeg3demux_read_prev_char(stream->demuxer);
}
/* Reconfigure for forward operation */
void mpeg3bits_start_forward(mpeg3_bits_t* stream)
{
int i;
for(i = 0; i < stream->bfr_size; i += 8)
if(stream->input_ptr)
stream->input_ptr++;
else
mpeg3demux_read_char(stream->demuxer);
}
/* Erase the buffer with the next 4 bytes in the file. */
int mpeg3bits_refill(mpeg3_bits_t* stream)
{
stream->bit_number = 32;
stream->bfr_size = 32;
if(stream->input_ptr)
{
stream->bfr = (unsigned int)(*stream->input_ptr++) << 24;
stream->bfr |= (unsigned int)(*stream->input_ptr++) << 16;
stream->bfr |= (unsigned int)(*stream->input_ptr++) << 8;
stream->bfr |= *stream->input_ptr++;
}
else
{
stream->bfr = mpeg3demux_read_char(stream->demuxer) << 24;
stream->bfr |= mpeg3demux_read_char(stream->demuxer) << 16;
stream->bfr |= mpeg3demux_read_char(stream->demuxer) << 8;
stream->bfr |= mpeg3demux_read_char(stream->demuxer);
}
return mpeg3demux_eof(stream->demuxer);
}
/* Erase the buffer with the previous 4 bytes in the file. */
int mpeg3bits_refill_backwards(mpeg3_bits_t* stream)
{
stream->bit_number = 0;
stream->bfr_size = 32;
stream->bfr = mpeg3demux_read_prev_char(stream->demuxer);
stream->bfr |= (unsigned int)mpeg3demux_read_prev_char(stream->demuxer) << 8;
stream->bfr |= (unsigned int)mpeg3demux_read_prev_char(stream->demuxer) << 16;
stream->bfr |= (unsigned int)mpeg3demux_read_prev_char(stream->demuxer) << 24;
return mpeg3demux_eof(stream->demuxer);
}
int mpeg3bits_byte_align(mpeg3_bits_t *stream)
{
stream->bit_number = (stream->bit_number + 7) & 0xf8;
return 0;
}
int mpeg3bits_seek_end(mpeg3_bits_t* stream)
{
stream->bfr_size = stream->bit_number = 0;
return mpeg3demux_seek_byte(stream->demuxer, mpeg3demuxer_total_bytes(stream->demuxer));
}
int mpeg3bits_seek_start(mpeg3_bits_t* stream)
{
stream->bfr_size = stream->bit_number = 0;
return mpeg3demux_seek_byte(stream->demuxer, 0);
}
int mpeg3bits_seek_time(mpeg3_bits_t* stream, double time_position)
{
stream->bfr_size = stream->bit_number = 0;
return mpeg3demux_seek_time(stream->demuxer, time_position);
}
int mpeg3bits_seek_byte(mpeg3_bits_t* stream, long position)
{
stream->bfr_size = stream->bit_number = 0;
return mpeg3demux_seek_byte(stream->demuxer, position);
}
int mpeg3bits_seek_percentage(mpeg3_bits_t* stream, double percentage)
{
stream->bfr_size = stream->bit_number = 0;
return mpeg3demux_seek_percentage(stream->demuxer, percentage);
}
int mpeg3bits_tell(mpeg3_bits_t* stream)
{
return mpeg3demux_tell(stream->demuxer);
}
int mpeg3bits_getbitoffset(mpeg3_bits_t *stream)
{
return stream->bit_number & 7;
}
|
