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
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
// liba52 sample by A'rpi/ESP-team
// reads ac3 stream form stdin, decodes and downmix to s16 stereo pcm and
// writes it to stdout. resulting stream playbackable with sox:
// play -c 2 -r 48000 out.sw
//#define TIMING //needs Pentium or newer
#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>
#include "a52.h"
static sample_t * samples;
static a52_state_t state;
static uint8_t buf[3840];
static int buf_size=0;
static int16_t out_buf[6*256*6];
#ifdef TIMING
static inline long long rdtsc()
{
long long l;
asm volatile( "rdtsc\n\t"
: "=A" (l)
);
// printf("%d\n", int(l/1000));
return l;
}
#define STARTTIMING t=rdtsc();
#define ENDTIMING sum+=rdtsc()-t; t=rdtsc();
#else
#define STARTTIMING ;
#define ENDTIMING ;
#endif
static inline int16_t convert (int32_t i)
{
if (i > 0x43c07fff)
return 32767;
else if (i < 0x43bf8000)
return -32768;
else
return i - 0x43c00000;
}
static inline void float_to_int (float * _f, int16_t * s16, int flags)
{
int i;
int32_t * f = (int32_t *) _f;
switch (flags) {
case A52_MONO:
for (i = 0; i < 256; i++) {
s16[5*i] = s16[5*i+1] = s16[5*i+2] = s16[5*i+3] = 0;
s16[5*i+4] = convert (f[i]);
}
break;
case A52_CHANNEL:
case A52_STEREO:
case A52_DOLBY:
for (i = 0; i < 256; i++) {
s16[2*i] = convert (f[i]);
s16[2*i+1] = convert (f[i+256]);
}
break;
case A52_3F:
for (i = 0; i < 256; i++) {
s16[5*i] = convert (f[i]);
s16[5*i+1] = convert (f[i+512]);
s16[5*i+2] = s16[5*i+3] = 0;
s16[5*i+4] = convert (f[i+256]);
}
break;
case A52_2F2R:
for (i = 0; i < 256; i++) {
s16[4*i] = convert (f[i]);
s16[4*i+1] = convert (f[i+256]);
s16[4*i+2] = convert (f[i+512]);
s16[4*i+3] = convert (f[i+768]);
}
break;
case A52_3F2R:
for (i = 0; i < 256; i++) {
s16[5*i] = convert (f[i]);
s16[5*i+1] = convert (f[i+512]);
s16[5*i+2] = convert (f[i+768]);
s16[5*i+3] = convert (f[i+1024]);
s16[5*i+4] = convert (f[i+256]);
}
break;
case A52_MONO | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = s16[6*i+1] = s16[6*i+2] = s16[6*i+3] = 0;
s16[6*i+4] = convert (f[i+256]);
s16[6*i+5] = convert (f[i]);
}
break;
case A52_CHANNEL | A52_LFE:
case A52_STEREO | A52_LFE:
case A52_DOLBY | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = convert (f[i+256]);
s16[6*i+1] = convert (f[i+512]);
s16[6*i+2] = s16[6*i+3] = s16[6*i+4] = 0;
s16[6*i+5] = convert (f[i]);
}
break;
case A52_3F | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = convert (f[i+256]);
s16[6*i+1] = convert (f[i+768]);
s16[6*i+2] = s16[6*i+3] = 0;
s16[6*i+4] = convert (f[i+512]);
s16[6*i+5] = convert (f[i]);
}
break;
case A52_2F2R | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = convert (f[i+256]);
s16[6*i+1] = convert (f[i+512]);
s16[6*i+2] = convert (f[i+768]);
s16[6*i+3] = convert (f[i+1024]);
s16[6*i+4] = 0;
s16[6*i+5] = convert (f[i]);
}
break;
case A52_3F2R | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = convert (f[i+256]);
s16[6*i+1] = convert (f[i+768]);
s16[6*i+2] = convert (f[i+1024]);
s16[6*i+3] = convert (f[i+1280]);
s16[6*i+4] = convert (f[i+512]);
s16[6*i+5] = convert (f[i]);
}
break;
}
}
int main(){
int accel=0;
int sample_rate=0;
int bit_rate=0;
#ifdef TIMING
long long t, sum=0;
#endif
samples = a52_init (accel);
if (samples == NULL) {
fprintf (stderr, "A52 init failed\n");
return 1;
}
while(1){
int length,i;
int16_t *s16;
sample_t level=1, bias=384;
int flags=0;
while(buf_size<7){
int c=getchar();
if(c<0) goto eof;
buf[buf_size++]=c;
}
STARTTIMING
length = a52_syncinfo (buf, &flags, &sample_rate, &bit_rate);
ENDTIMING
if(!length){
// bad file => resync
memcpy(buf,buf+1,6);
--buf_size;
continue;
}
fprintf(stderr,"sync. %d bytes 0x%X %d Hz %d kbit\n",length,flags,sample_rate,bit_rate);
while(buf_size<length){
buf[buf_size++]=getchar();
}
buf_size=0;
// decode:
flags=A52_STEREO; // A52_DOLBY // A52_2F2R // A52_3F2R | A52_LFE
flags |= A52_ADJUST_LEVEL;
STARTTIMING
if (a52_frame (&state, buf, &flags, &level, bias))
{ fprintf(stderr,"error at decoding\n"); continue; }
ENDTIMING
// a52_dynrng (&state, NULL, NULL); // disable dynamic range compensation
s16 = out_buf;
for (i = 0; i < 6; i++) {
int32_t * f = (int32_t *) samples;
int i;
STARTTIMING
if (a52_block (&state, samples))
{ fprintf(stderr,"error at sampling\n"); break; }
ENDTIMING
// resample to STEREO/DOLBY:
for (i = 0; i < 256; i++) {
s16[2*i] = convert (f[i]);
s16[2*i+1] = convert (f[i+256]);
}
s16+=2*i;
}
fwrite(out_buf,6*256*2*2,1,stdout);
}
eof:
#ifdef TIMING
fprintf(stderr, "%4.4fm cycles\n",sum/1000000.0);
#endif
}
|
