This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
/
SDL_dcaudio.c
245 lines (212 loc) · 6.89 KB
1
2
/*
SDL - Simple DirectMedia Layer
3
Copyright (C) 1997-2009 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
#include "../SDL_audiomem.h"
#include "../SDL_audio_c.h"
31
32
33
34
35
36
37
#include "SDL_dcaudio.h"
#include "aica.h"
#include <dc/spu.h>
#define SPU_RAM_BASE 0xa0800000
38
39
static void
spu_memload_stereo8(int leftpos, int rightpos, void *src0, size_t size)
40
{
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
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();
}
59
60
}
61
62
static void
spu_memload_stereo16(int leftpos, int rightpos, void *src0, size_t size)
63
{
64
65
66
67
68
69
70
71
72
73
74
75
76
77
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();
}
78
79
}
80
static void
81
DCAUD_PlayDevice(_THIS)
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
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);
}
}
126
127
}
128
static Uint8 *
129
DCAUD_GetDeviceBuf(_THIS)
130
{
131
return (this->hidden->mixbuf);
132
133
}
134
/* This function waits until it is possible to write a full sound buffer */
135
static void
136
DCAUD_WaitDevice(_THIS)
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
if (this->hidden->playing) {
/* wait */
while (aica_get_pos(0) / this->spec.samples == this->hidden->nextbuf) {
thd_pass();
}
}
}
static void
DCAUD_CloseDevice(_THIS)
{
if (this->hidden != NULL) {
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;
}
SDL_free(this->hidden);
this->hidden = NULL;
/* !!! FIXME: is there a reverse of spu_init()? */
162
}
163
164
}
165
static int
166
DCAUD_OpenDevice(_THIS, SDL_AudioSpec * spec)
167
{
168
169
SDL_AudioFormat test_format = SDL_FirstAudioFormat(spec->format);
int valid_datatype = 0;
170
171
172
/* Initialize all variables that we clean on shutdown */
this->hidden = (struct SDL_PrivateAudioData *)
173
SDL_malloc((sizeof *this->hidden));
174
175
176
177
178
179
180
181
if (this->hidden == NULL) {
SDL_OutOfMemory();
return 0;
}
SDL_memset(this->hidden, 0, (sizeof *this->hidden));
spu_init();
182
183
184
185
while ((!valid_datatype) && (test_format)) {
spec->format = test_format;
switch (test_format) {
/* only formats Dreamcast accepts... */
186
187
188
189
190
191
192
193
case AUDIO_S8:
case AUDIO_S16LSB:
valid_datatype = 1;
break;
default:
test_format = SDL_NextAudioFormat();
break;
194
195
196
}
}
197
if (!valid_datatype) { /* shouldn't happen, but just in case... */
198
DCAUD_CloseDevice(this);
199
SDL_SetError("Unsupported audio format");
200
return 0;
201
202
}
203
if (spec->channels > 2)
204
spec->channels = 2; /* no more than stereo on the Dreamcast. */
205
206
207
208
209
210
211
212
/* 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) {
213
214
215
DCAUD_CloseDevice(this);
SDL_OutOfMemory();
return 0;
216
217
218
219
220
221
222
223
}
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. :-) */
224
225
226
227
return 1;
}
static int
228
DCAUD_Init(SDL_AudioDriverImpl * impl)
229
230
231
232
233
234
235
236
237
238
{
/* Set the function pointers */
impl->OpenDevice = DCAUD_OpenDevice;
impl->PlayDevice = DCAUD_PlayDevice;
impl->WaitDevice = DCAUD_WaitDevice;
impl->GetDeviceBuf = DCAUD_GetDeviceBuf;
impl->CloseDevice = DCAUD_CloseDevice;
impl->OnlyHasDefaultOutputDevice = 1;
return 1;
239
}
240
241
242
243
244
AudioBootStrap DCAUD_bootstrap = {
"dcaudio", "Dreamcast AICA audio", DCAUD_Init, 0
};
245
/* vi: set ts=4 sw=4 expandtab: */