This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
/
SDL_dcaudio.c
267 lines (231 loc) · 7.33 KB
1
2
/*
SDL - Simple DirectMedia Layer
3
Copyright (C) 1997-2006 Sam Lantinga
4
5
This library is free software; you can redistribute it and/or
6
modify it under the terms of the GNU Lesser General Public
7
License as published by the Free Software Foundation; either
8
version 2.1 of the License, or (at your option) any later version.
9
10
11
12
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
13
Lesser General Public License for more details.
14
15
16
17
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19
20
Sam Lantinga
slouken@libsdl.org
21
22
*/
23
#include "SDL_config.h"
24
25
26
/* Output dreamcast aica */
27
#include "SDL_timer.h"
28
#include "SDL_audio.h"
29
30
31
#include "../SDL_audiomem.h"
#include "../SDL_audio_c.h"
#include "../SDL_audiodev_c.h"
32
33
34
35
36
37
#include "SDL_dcaudio.h"
#include "aica.h"
#include <dc/spu.h>
/* Audio driver functions */
38
static int DCAUD_OpenAudio(_THIS, SDL_AudioSpec * spec);
39
40
41
42
43
44
static void DCAUD_WaitAudio(_THIS);
static void DCAUD_PlayAudio(_THIS);
static Uint8 *DCAUD_GetAudioBuf(_THIS);
static void DCAUD_CloseAudio(_THIS);
/* Audio driver bootstrap functions */
45
46
static int
DCAUD_Available(void)
47
{
48
return 1;
49
50
}
51
52
static void
DCAUD_DeleteDevice(SDL_AudioDevice * device)
53
{
54
55
SDL_free(device->hidden);
SDL_free(device);
56
57
}
58
59
static SDL_AudioDevice *
DCAUD_CreateDevice(int devindex)
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
SDL_AudioDevice *this;
/* Initialize all variables that we clean on shutdown */
this = (SDL_AudioDevice *) SDL_malloc(sizeof(SDL_AudioDevice));
if (this) {
SDL_memset(this, 0, (sizeof *this));
this->hidden = (struct SDL_PrivateAudioData *)
SDL_malloc((sizeof *this->hidden));
}
if ((this == NULL) || (this->hidden == NULL)) {
SDL_OutOfMemory();
if (this) {
SDL_free(this);
}
return (0);
}
SDL_memset(this->hidden, 0, (sizeof *this->hidden));
/* Set the function pointers */
this->OpenAudio = DCAUD_OpenAudio;
this->WaitAudio = DCAUD_WaitAudio;
this->PlayAudio = DCAUD_PlayAudio;
this->GetAudioBuf = DCAUD_GetAudioBuf;
this->CloseAudio = DCAUD_CloseAudio;
this->free = DCAUD_DeleteDevice;
spu_init();
return this;
91
92
93
}
AudioBootStrap DCAUD_bootstrap = {
94
95
"dcaudio", "Dreamcast AICA audio",
DCAUD_Available, DCAUD_CreateDevice
96
97
98
};
/* This function waits until it is possible to write a full sound buffer */
99
100
static void
DCAUD_WaitAudio(_THIS)
101
{
102
103
104
105
106
107
if (this->hidden->playing) {
/* wait */
while (aica_get_pos(0) / this->spec.samples == this->hidden->nextbuf) {
thd_pass();
}
}
108
109
110
111
}
#define SPU_RAM_BASE 0xa0800000
112
113
static void
spu_memload_stereo8(int leftpos, int rightpos, void *src0, size_t size)
114
{
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
uint8 *src = src0;
uint32 *left = (uint32 *) (leftpos + SPU_RAM_BASE);
uint32 *right = (uint32 *) (rightpos + SPU_RAM_BASE);
size = (size + 7) / 8;
while (size--) {
unsigned lval, rval;
lval = *src++;
rval = *src++;
lval |= (*src++) << 8;
rval |= (*src++) << 8;
lval |= (*src++) << 16;
rval |= (*src++) << 16;
lval |= (*src++) << 24;
rval |= (*src++) << 24;
g2_write_32(left++, lval);
g2_write_32(right++, rval);
g2_fifo_wait();
}
133
134
}
135
136
static void
spu_memload_stereo16(int leftpos, int rightpos, void *src0, size_t size)
137
{
138
139
140
141
142
143
144
145
146
147
148
149
150
151
uint16 *src = src0;
uint32 *left = (uint32 *) (leftpos + SPU_RAM_BASE);
uint32 *right = (uint32 *) (rightpos + SPU_RAM_BASE);
size = (size + 7) / 8;
while (size--) {
unsigned lval, rval;
lval = *src++;
rval = *src++;
lval |= (*src++) << 16;
rval |= (*src++) << 16;
g2_write_32(left++, lval);
g2_write_32(right++, rval);
g2_fifo_wait();
}
152
153
}
154
155
static void
DCAUD_PlayAudio(_THIS)
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
SDL_AudioSpec *spec = &this->spec;
unsigned int offset;
if (this->hidden->playing) {
/* wait */
while (aica_get_pos(0) / spec->samples == this->hidden->nextbuf) {
thd_pass();
}
}
offset = this->hidden->nextbuf * spec->size;
this->hidden->nextbuf ^= 1;
/* Write the audio data, checking for EAGAIN on broken audio drivers */
if (spec->channels == 1) {
spu_memload(this->hidden->leftpos + offset, this->hidden->mixbuf,
this->hidden->mixlen);
} else {
offset /= 2;
if ((this->spec.format & 255) == 8) {
spu_memload_stereo8(this->hidden->leftpos + offset,
this->hidden->rightpos + offset,
this->hidden->mixbuf, this->hidden->mixlen);
} else {
spu_memload_stereo16(this->hidden->leftpos + offset,
this->hidden->rightpos + offset,
this->hidden->mixbuf, this->hidden->mixlen);
}
}
if (!this->hidden->playing) {
int mode;
this->hidden->playing = 1;
mode = (spec->format == AUDIO_S8) ? SM_8BIT : SM_16BIT;
if (spec->channels == 1) {
aica_play(0, mode, this->hidden->leftpos, 0,
spec->samples * 2, spec->freq, 255, 128, 1);
} else {
aica_play(0, mode, this->hidden->leftpos, 0,
spec->samples * 2, spec->freq, 255, 0, 1);
aica_play(1, mode, this->hidden->rightpos, 0,
spec->samples * 2, spec->freq, 255, 255, 1);
}
}
200
201
}
202
203
static Uint8 *
DCAUD_GetAudioBuf(_THIS)
204
{
205
return (this->hidden->mixbuf);
206
207
}
208
209
static void
DCAUD_CloseAudio(_THIS)
210
{
211
212
213
214
215
216
217
aica_stop(0);
if (this->spec.channels == 2)
aica_stop(1);
if (this->hidden->mixbuf != NULL) {
SDL_FreeAudioMem(this->hidden->mixbuf);
this->hidden->mixbuf = NULL;
}
218
219
}
220
221
static int
DCAUD_OpenAudio(_THIS, SDL_AudioSpec * spec)
222
{
223
224
225
226
227
228
SDL_AudioFormat test_format = SDL_FirstAudioFormat(spec->format);
int valid_datatype = 0;
while ((!valid_datatype) && (test_format)) {
spec->format = test_format;
switch (test_format) {
/* only formats Dreamcast accepts... */
229
230
231
232
233
234
235
236
case AUDIO_S8:
case AUDIO_S16LSB:
valid_datatype = 1;
break;
default:
test_format = SDL_NextAudioFormat();
break;
237
238
239
}
}
240
if (!valid_datatype) { /* shouldn't happen, but just in case... */
241
242
243
244
SDL_SetError("Unsupported audio format");
return (-1);
}
245
if (spec->channels > 2)
246
spec->channels = 2; /* no more than stereo on the Dreamcast. */
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
/* Update the fragment size as size in bytes */
SDL_CalculateAudioSpec(spec);
/* Allocate mixing buffer */
this->hidden->mixlen = spec->size;
this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
if (this->hidden->mixbuf == NULL) {
return (-1);
}
SDL_memset(this->hidden->mixbuf, spec->silence, spec->size);
this->hidden->leftpos = 0x11000;
this->hidden->rightpos = 0x11000 + spec->size;
this->hidden->playing = 0;
this->hidden->nextbuf = 0;
/* We're ready to rock and roll. :-) */
return (0);
265
}
266
267
/* vi: set ts=4 sw=4 expandtab: */