loopwavequeue.c
2
Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
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
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely.
*/
/* Program to load a wave file and loop playing it using SDL sound queueing */
#include <stdio.h>
#include <stdlib.h>
#ifdef __EMSCRIPTEN__
#include <emscripten/emscripten.h>
#endif
#include "SDL.h"
#if HAVE_SIGNAL_H
#include <signal.h>
#endif
28
static struct
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
{
SDL_AudioSpec spec;
Uint8 *sound; /* Pointer to wave data */
Uint32 soundlen; /* Length of wave data */
} wave;
/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
SDL_Quit();
exit(rc);
}
static int done = 0;
void
poked(int sig)
{
done = 1;
}
void
loop()
{
#ifdef __EMSCRIPTEN__
if (done || (SDL_GetAudioStatus() != SDL_AUDIO_PLAYING)) {
emscripten_cancel_main_loop();
}
else
#endif
{
/* The device from SDL_OpenAudio() is always device #1. */
const Uint32 queued = SDL_GetQueuedAudioSize(1);
SDL_Log("Device has %u bytes queued.\n", (unsigned int) queued);
if (queued <= 8192) { /* time to requeue the whole thing? */
if (SDL_QueueAudio(1, wave.sound, wave.soundlen) == 0) {
SDL_Log("Device queued %u more bytes.\n", (unsigned int) wave.soundlen);
} else {
SDL_Log("Device FAILED to queue %u more bytes: %s\n", (unsigned int) wave.soundlen, SDL_GetError());
}
}
}
}
int
main(int argc, char *argv[])
{
char filename[4096];
79
80
/* Enable standard application logging */
SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
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
/* Load the SDL library */
if (SDL_Init(SDL_INIT_AUDIO) < 0) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
return (1);
}
if (argc > 1) {
SDL_strlcpy(filename, argv[1], sizeof(filename));
} else {
SDL_strlcpy(filename, "sample.wav", sizeof(filename));
}
/* Load the wave file into memory */
if (SDL_LoadWAV(filename, &wave.spec, &wave.sound, &wave.soundlen) == NULL) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", filename, SDL_GetError());
quit(1);
}
wave.spec.callback = NULL; /* we'll push audio. */
#if HAVE_SIGNAL_H
/* Set the signals */
#ifdef SIGHUP
signal(SIGHUP, poked);
#endif
signal(SIGINT, poked);
#ifdef SIGQUIT
signal(SIGQUIT, poked);
#endif
signal(SIGTERM, poked);
#endif /* HAVE_SIGNAL_H */
/* Initialize fillerup() variables */
if (SDL_OpenAudio(&wave.spec, NULL) < 0) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't open audio: %s\n", SDL_GetError());
SDL_FreeWAV(wave.sound);
quit(2);
}
/*static x[99999]; SDL_QueueAudio(1, x, sizeof (x));*/
/* Let the audio run */
SDL_PauseAudio(0);
done = 0;
/* Note that we stuff the entire audio buffer into the queue in one
shot. Most apps would want to feed it a little at a time, as it
plays, but we're going for simplicity here. */
#ifdef __EMSCRIPTEN__
emscripten_set_main_loop(loop, 0, 1);
#else
while (!done && (SDL_GetAudioStatus() == SDL_AUDIO_PLAYING))
{
loop();
SDL_Delay(100); /* let it play for awhile. */
}
#endif
/* Clean up on signal */
SDL_CloseAudio();
SDL_FreeWAV(wave.sound);
SDL_Quit();
return 0;
}
/* vi: set ts=4 sw=4 expandtab: */