SDL_mintaudio.c
2
3
SDL - Simple DirectMedia Layer
Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga
5
6
7
8
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.
10
11
12
13
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.
15
16
17
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
19
20
21
Sam Lantinga
slouken@libsdl.org
*/
23
24
/*
Audio interrupt variables and callback function
26
27
Patrice Mandin
*/
29
#include <string.h>
31
32
#include "SDL_types.h"
#include "SDL_audio.h"
34
35
#include "SDL_mintaudio.h"
#include "SDL_mintaudio_stfa.h"
37
/* The audio device */
39
40
SDL_AudioDevice *SDL_MintAudio_device;
Uint8 *SDL_MintAudio_audiobuf[2]; /* Pointers to buffers */
41
42
43
unsigned long SDL_MintAudio_audiosize; /* Length of audio buffer=spec->size */
unsigned short SDL_MintAudio_numbuf; /* Buffer to play */
unsigned short SDL_MintAudio_mutex;
44
cookie_stfa_t *SDL_MintAudio_stfa;
46
/* The callback function, called by each driver whenever needed */
47
48
49
50
51
52
void SDL_MintAudio_Callback(void)
{
Uint8 *buffer;
buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
53
54
55
56
57
58
59
60
memset(buffer, SDL_MintAudio_device->spec.silence, SDL_MintAudio_device->spec.size);
if ( ! SDL_MintAudio_device->paused ) {
if ( SDL_MintAudio_device->convert.needed ) {
SDL_MintAudio_device->spec.callback(SDL_MintAudio_device->spec.userdata,
(Uint8 *)SDL_MintAudio_device->convert.buf,SDL_MintAudio_device->convert.len);
SDL_ConvertAudio(&SDL_MintAudio_device->convert);
memcpy(buffer, SDL_MintAudio_device->convert.buf, SDL_MintAudio_device->convert.len_cvt);
61
} else {
62
SDL_MintAudio_device->spec.callback(SDL_MintAudio_device->spec.userdata, buffer, SDL_MintAudio_device->spec.size);
63
64
65
66
}
}
}
67
68
/* Simple function to search for the nearest frequency */
int SDL_MintAudio_SearchFrequency(_THIS, int falcon_codec, int desired_freq)
69
70
71
{
int i;
72
73
74
/* Only 1 freq ? */
if (MINTAUDIO_nfreq==1) {
return(MINTAUDIO_sfreq);
77
78
79
80
81
82
/* Check the array */
for (i=MINTAUDIO_sfreq; i<MINTAUDIO_nfreq-1; i++) {
/* Remove unusable falcon codec frequencies */
if (falcon_codec) {
if ((i==6) || (i==8) || (i==10)) {
continue;
86
87
if (desired_freq >= ((MINTAUDIO_hardfreq[i]+MINTAUDIO_hardfreq[i+1])>>1)) {
return i;
91
92
/* Not in the array, give the latest */
return MINTAUDIO_nfreq-1;