loopwave.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
/* Program to load a wave file and loop playing it using SDL sound */
/* loopwaves.c is much more robust in handling WAVE files --
This is only for simple WAVEs
*/
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include "SDL.h"
#include "SDL_audio.h"
struct {
SDL_AudioSpec spec;
Uint8 *sound; /* Pointer to wave data */
Uint32 soundlen; /* Length of wave data */
int soundpos; /* Current play position */
} wave;
22
23
24
25
26
27
28
29
30
/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void quit(int rc)
{
SDL_Quit();
exit(rc);
}
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
void fillerup(void *unused, Uint8 *stream, int len)
{
Uint8 *waveptr;
int waveleft;
/* Set up the pointers */
waveptr = wave.sound + wave.soundpos;
waveleft = wave.soundlen - wave.soundpos;
/* Go! */
while ( waveleft <= len ) {
SDL_MixAudio(stream, waveptr, waveleft, SDL_MIX_MAXVOLUME);
stream += waveleft;
len -= waveleft;
waveptr = wave.sound;
waveleft = wave.soundlen;
wave.soundpos = 0;
}
SDL_MixAudio(stream, waveptr, len, SDL_MIX_MAXVOLUME);
wave.soundpos += len;
}
static int done = 0;
void poked(int sig)
{
done = 1;
}
int main(int argc, char *argv[])
{
char name[32];
/* Load the SDL library */
if ( SDL_Init(SDL_INIT_AUDIO) < 0 ) {
fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
67
68
69
70
}
if ( argv[1] == NULL ) {
fprintf(stderr, "Usage: %s <wavefile>\n", argv[0]);
72
73
74
75
76
77
78
}
/* Load the wave file into memory */
if ( SDL_LoadWAV(argv[1],
&wave.spec, &wave.sound, &wave.soundlen) == NULL ) {
fprintf(stderr, "Couldn't load %s: %s\n",
argv[1], SDL_GetError());
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
}
wave.spec.callback = fillerup;
/* Set the signals */
#ifdef SIGHUP
signal(SIGHUP, poked);
#endif
signal(SIGINT, poked);
#ifdef SIGQUIT
signal(SIGQUIT, poked);
#endif
signal(SIGTERM, poked);
/* Initialize fillerup() variables */
if ( SDL_OpenAudio(&wave.spec, NULL) < 0 ) {
fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
SDL_FreeWAV(wave.sound);
98
99
100
101
102
103
104
105
106
107
108
}
SDL_PauseAudio(0);
/* Let the audio run */
printf("Using audio driver: %s\n", SDL_AudioDriverName(name, 32));
while ( ! done && (SDL_GetAudioStatus() == SDL_AUDIO_PLAYING) )
SDL_Delay(1000);
/* Clean up on signal */
SDL_CloseAudio();
SDL_FreeWAV(wave.sound);
110
111
return(0);
}