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
|
/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997-2012 Sam Lantinga
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Sam Lantinga
slouken@libsdl.org
*/
#include "SDL_config.h"
/*
Audio interrupt variables and callback function
Patrice Mandin
*/
#include <unistd.h>
#include <mint/osbind.h>
#include <mint/falcon.h>
#include <mint/mintbind.h>
#include <mint/cookie.h>
#include "SDL_audio.h"
#include "SDL_mintaudio.h"
#include "SDL_mintaudio_stfa.h"
/* The audio device */
SDL_AudioDevice *SDL_MintAudio_device;
Uint8 *SDL_MintAudio_audiobuf[2]; /* Pointers to buffers */
unsigned long SDL_MintAudio_audiosize; /* Length of audio buffer=spec->size */
volatile unsigned short SDL_MintAudio_numbuf; /* Buffer to play */
volatile unsigned short SDL_MintAudio_mutex;
volatile unsigned long SDL_MintAudio_clocktics;
cookie_stfa_t *SDL_MintAudio_stfa;
unsigned short SDL_MintAudio_hasfpu;
/* MiNT thread variables */
SDL_bool SDL_MintAudio_mint_present;
SDL_bool SDL_MintAudio_quit_thread;
SDL_bool SDL_MintAudio_thread_finished;
long SDL_MintAudio_thread_pid;
/* The callback function, called by each driver whenever needed */
void SDL_MintAudio_Callback(void)
{
Uint8 *buffer;
SDL_AudioDevice *audio = SDL_MintAudio_device;
buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
SDL_memset(buffer, audio->spec.silence, audio->spec.size);
if (audio->paused)
return;
if (audio->convert.needed) {
int silence;
if ( audio->convert.src_format == AUDIO_U8 ) {
silence = 0x80;
} else {
silence = 0;
}
SDL_memset(audio->convert.buf, silence, audio->convert.len);
audio->spec.callback(audio->spec.userdata,
(Uint8 *)audio->convert.buf,audio->convert.len);
SDL_ConvertAudio(&audio->convert);
SDL_memcpy(buffer, audio->convert.buf, audio->convert.len_cvt);
} else {
audio->spec.callback(audio->spec.userdata, buffer, audio->spec.size);
}
}
/* Add a new frequency/clock/predivisor to the current list */
void SDL_MintAudio_AddFrequency(_THIS, Uint32 frequency, Uint32 clock,
Uint32 prediv, int gpio_bits)
{
int i, p;
if (MINTAUDIO_freqcount==MINTAUDIO_maxfreqs) {
return;
}
/* Search where to insert the frequency (highest first) */
for (p=0; p<MINTAUDIO_freqcount; p++) {
if (frequency > MINTAUDIO_frequencies[p].frequency) {
break;
}
}
/* Put all following ones farer */
if (MINTAUDIO_freqcount>0) {
for (i=MINTAUDIO_freqcount; i>p; i--) {
SDL_memcpy(&MINTAUDIO_frequencies[i], &MINTAUDIO_frequencies[i-1], sizeof(mint_frequency_t));
}
}
/* And insert new one */
MINTAUDIO_frequencies[p].frequency = frequency;
MINTAUDIO_frequencies[p].masterclock = clock;
MINTAUDIO_frequencies[p].predivisor = prediv;
MINTAUDIO_frequencies[p].gpio_bits = gpio_bits;
MINTAUDIO_freqcount++;
}
/* Search for the nearest frequency */
int SDL_MintAudio_SearchFrequency(_THIS, int desired_freq)
{
int i;
/* Only 1 freq ? */
if (MINTAUDIO_freqcount==1) {
return 0;
}
/* Check the array */
for (i=0; i<MINTAUDIO_freqcount; i++) {
if (desired_freq >= ((MINTAUDIO_frequencies[i].frequency+
MINTAUDIO_frequencies[i+1].frequency)>>1)) {
return i;
}
}
/* Not in the array, give the latest */
return MINTAUDIO_freqcount-1;
}
/* Check if FPU is present */
void SDL_MintAudio_CheckFpu(void)
{
long cookie_fpu;
SDL_MintAudio_hasfpu = 0;
if (Getcookie(C__FPU, &cookie_fpu) != C_FOUND) {
return;
}
switch ((cookie_fpu>>16)&0xfffe) {
case 2:
case 4:
case 6:
case 8:
case 16:
SDL_MintAudio_hasfpu = 1;
break;
}
}
/* The thread function, used under MiNT with xbios */
int SDL_MintAudio_Thread(long param)
{
SndBufPtr pointers;
SDL_bool buffers_filled[2] = {SDL_FALSE, SDL_FALSE};
SDL_MintAudio_thread_finished = SDL_FALSE;
while (!SDL_MintAudio_quit_thread) {
if (Buffptr(&pointers)!=0)
continue;
if (( (unsigned long)pointers.play>=(unsigned long)SDL_MintAudio_audiobuf[0])
&& ( (unsigned long)pointers.play<=(unsigned long)SDL_MintAudio_audiobuf[1]))
{
/* DMA is reading buffer #0, setup buffer #1 if not already done */
if (!buffers_filled[1]) {
SDL_MintAudio_numbuf = 1;
SDL_MintAudio_Callback();
Setbuffer(0, SDL_MintAudio_audiobuf[1], SDL_MintAudio_audiobuf[1] + SDL_MintAudio_audiosize);
buffers_filled[1]=SDL_TRUE;
buffers_filled[0]=SDL_FALSE;
}
} else {
/* DMA is reading buffer #1, setup buffer #0 if not already done */
if (!buffers_filled[0]) {
SDL_MintAudio_numbuf = 0;
SDL_MintAudio_Callback();
Setbuffer(0, SDL_MintAudio_audiobuf[0], SDL_MintAudio_audiobuf[0] + SDL_MintAudio_audiosize);
buffers_filled[0]=SDL_TRUE;
buffers_filled[1]=SDL_FALSE;
}
}
usleep(100);
}
SDL_MintAudio_thread_finished = SDL_TRUE;
return 0;
}
void SDL_MintAudio_WaitThread(void)
{
if (!SDL_MintAudio_mint_present)
return;
if (SDL_MintAudio_thread_finished)
return;
SDL_MintAudio_quit_thread = SDL_TRUE;
while (!SDL_MintAudio_thread_finished) {
Syield();
}
}
|
