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
223
224
225
226
227
|
//
// BeOS code for amp-0.7.4, (C) 1997 Andy Lo A Foe
//
#include <MediaKit.h>
#include <KernelKit.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "transform.h"
#include "audioIO.h"
#include "audio.h"
// Define the streambuf size here. streambuf is used
// as a simple fit buffer.
#define STREAMBUF_SIZE (32*1152)
long bytes_in_streambuf;
// streambuf definition and base indicator
BSubscriber *the_sub;
BDACStream *the_stream;
sem_id ok_to_read;
sem_id ok_to_write;
char streambuf[STREAMBUF_SIZE];
char *readbase;
static int au_vol = 100;
// Define our own printout function since we are
// first writing in the streambuf (not needed, I think,
// but I don't know if the DACStream accepts a buffer
// size of 1152. Try it...
void printout(void)
{
if (A_WRITE_TO_FILE) {
#ifndef NO_BYTE_SWAPPING
int i,j;
short *ptr;
if (nch==2) {
ptr=(short*)stereo_samples;
i=j=32 * 18 * 2;
} else {
ptr=(short*)mono_samples;
i=j=32 * 18;
}
for (;i>=0;--i)
ptr[i] = ptr[i] << 8 | ptr[i] >> 8;
#endif
if (nch==2)
fwrite(stereo_samples,1,sizeof stereo_samples,out_file);
else
fwrite(mono_samples,1,sizeof mono_samples,out_file);
}
if (A_AUDIO_PLAY) {
static char au_buf[STREAMBUF_SIZE];
static int au_ptr =0, avail = 0;
static int num_smp;
static char *readbase = &au_buf[0];
// Write amount of samples to copy somewhere
num_smp = (nch == 2 ? sizeof stereo_samples : sizeof mono_samples);
// Copy samples in the fit buffer
memcpy(au_buf+au_ptr,(nch == 2 ? (char *)stereo_samples : (char *)mono_samples),
num_smp);
// Increase fit buffer pointer and available sample count
au_ptr+=num_smp;
avail+=num_smp;
if (avail >= 4096) { // Are there enough smps to feed the stream?
audioWrite((char*)readbase,4096); // Feed it!
readbase+=4096; // Increase readbase
avail-=4096; // Decrease avail smps count
if (au_ptr == STREAMBUF_SIZE) { // At end of fit buffer?
au_ptr=0; // Reset all pointers
readbase=&au_buf[0];
}
}
}
}
// Fake Buffer functions, just to keep the sources clean,
// buffer.c should not be included in the link process...
int AUDIO_BUFFER_SIZE;
int
audioBufferOpen(int frequency, int stereo, int volume)
{
audioOpen(frequency, stereo, volume);
}
inline void
audioBufferWrite(char *buf,int bytes)
{
audioWrite(buf, bytes);
}
void
audioBufferClose()
{
audioClose();
}
int audioRead(char *buffer, int count)
{
//printf("acquiring ok_to_read (%d bytes)\n", count);
if (acquire_sem(ok_to_read)==B_NO_ERROR) {
for (int i=0; i < count;i++) {
*(buffer++)+=*(readbase++);
}
bytes_in_streambuf-=count;
if (bytes_in_streambuf <= 0) {
release_sem(ok_to_write);
bytes_in_streambuf = 0;
} else {
release_sem(ok_to_read);
}
}
return (0);
}
bool stream_func(void *arg, char *buf, size_t count, void *header)
{
audioRead(buf, count);
return TRUE;
}
void audioOpen() {
readbase = &streambuf[0];
bytes_in_streambuf = 0;
the_sub = new BSubscriber("amp DAC writer");
the_stream = new BDACStream();
the_sub->Subscribe(the_stream);
the_stream->SetSamplingRate(frequency);
// Create semaphores
ok_to_read = create_sem(0, "read sem");
ok_to_write = create_sem(1, "write sem");
}
void audioInit(int sampleSize,int frequency, int stereo)
{
// Initialize the streambuf
bytes_in_streambuf = 0;
memset(&streambuf, 0, STREAMBUF_SIZE);
// Enter the stream
the_sub->EnterStream(NULL, TRUE, NULL, stream_func, NULL, TRUE);
}
void audioSetVolume(int volume)
{
if (volume > 128) // This allows for a modest volume boost
volume = 128;
au_vol = volume;
}
void audioClose()
{
the_sub->ExitStream(TRUE);
the_sub->Unsubscribe();
delete_sem(ok_to_read);
delete_sem(ok_to_write);
delete the_sub;
delete the_stream;
}
// audioWrite is called from the player thread
int audioWrite(char *buffer, int count)
{
//printf("acquiring ok_to_write (%d bytes)\n", count);
if(acquire_sem(ok_to_write)==B_NO_ERROR)
{
memcpy(&streambuf, buffer, count);
if (au_vol != 100) { // Handle volume scaling here
short *b=(short *)&streambuf;
for (int i=0; i < count/2; i++) {
int v=((int)b[i]*au_vol)/100;
b[i]=(v>32767) ? 32767 : ((v<-32768) ? -32768 : v);
}
}
bytes_in_streambuf = count;
readbase = &streambuf[0];
release_sem(ok_to_read);
}
return 0;
}
|
