1 /*
2 Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
3
4 This software is provided 'as-is', without any express or implied
5 warranty. In no event will the authors be held liable for any damages
6 arising from the use of this software.
7
8 Permission is granted to anyone to use this software for any purpose,
9 including commercial applications, and to alter it and redistribute it
10 freely.
11 */
12
13 /* Program to load a wave file and loop playing it using SDL sound queueing */
14
15 #include <stdio.h>
16 #include <stdlib.h>
17
18 #ifdef __EMSCRIPTEN__
19 #include <emscripten/emscripten.h>
20 #endif
21
22 #include "SDL.h"
23
24 #if HAVE_SIGNAL_H
25 #include <signal.h>
26 #endif
27
28 static struct
29 {
30 SDL_AudioSpec spec;
31 Uint8 *sound; /* Pointer to wave data */
32 Uint32 soundlen; /* Length of wave data */
33 } wave;
34
35
36 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
37 static void
quit(int rc)38 quit(int rc)
39 {
40 SDL_Quit();
41 exit(rc);
42 }
43
44 static int done = 0;
45 void
poked(int sig)46 poked(int sig)
47 {
48 done = 1;
49 }
50
51 void
loop()52 loop()
53 {
54 #ifdef __EMSCRIPTEN__
55 if (done || (SDL_GetAudioStatus() != SDL_AUDIO_PLAYING)) {
56 emscripten_cancel_main_loop();
57 }
58 else
59 #endif
60 {
61 /* The device from SDL_OpenAudio() is always device #1. */
62 const Uint32 queued = SDL_GetQueuedAudioSize(1);
63 SDL_Log("Device has %u bytes queued.\n", (unsigned int) queued);
64 if (queued <= 8192) { /* time to requeue the whole thing? */
65 if (SDL_QueueAudio(1, wave.sound, wave.soundlen) == 0) {
66 SDL_Log("Device queued %u more bytes.\n", (unsigned int) wave.soundlen);
67 } else {
68 SDL_Log("Device FAILED to queue %u more bytes: %s\n", (unsigned int) wave.soundlen, SDL_GetError());
69 }
70 }
71 }
72 }
73
74 int
main(int argc,char * argv[])75 main(int argc, char *argv[])
76 {
77 char filename[4096];
78
79 /* Enable standard application logging */
80 SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
81
82 /* Load the SDL library */
83 if (SDL_Init(SDL_INIT_AUDIO) < 0) {
84 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
85 return (1);
86 }
87
88 if (argc > 1) {
89 SDL_strlcpy(filename, argv[1], sizeof(filename));
90 } else {
91 SDL_strlcpy(filename, "sample.wav", sizeof(filename));
92 }
93 /* Load the wave file into memory */
94 if (SDL_LoadWAV(filename, &wave.spec, &wave.sound, &wave.soundlen) == NULL) {
95 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", filename, SDL_GetError());
96 quit(1);
97 }
98
99 wave.spec.callback = NULL; /* we'll push audio. */
100
101 #if HAVE_SIGNAL_H
102 /* Set the signals */
103 #ifdef SIGHUP
104 signal(SIGHUP, poked);
105 #endif
106 signal(SIGINT, poked);
107 #ifdef SIGQUIT
108 signal(SIGQUIT, poked);
109 #endif
110 signal(SIGTERM, poked);
111 #endif /* HAVE_SIGNAL_H */
112
113 /* Initialize fillerup() variables */
114 if (SDL_OpenAudio(&wave.spec, NULL) < 0) {
115 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't open audio: %s\n", SDL_GetError());
116 SDL_FreeWAV(wave.sound);
117 quit(2);
118 }
119
120 /*static x[99999]; SDL_QueueAudio(1, x, sizeof (x));*/
121
122 /* Let the audio run */
123 SDL_PauseAudio(0);
124
125 done = 0;
126
127 /* Note that we stuff the entire audio buffer into the queue in one
128 shot. Most apps would want to feed it a little at a time, as it
129 plays, but we're going for simplicity here. */
130
131 #ifdef __EMSCRIPTEN__
132 emscripten_set_main_loop(loop, 0, 1);
133 #else
134 while (!done && (SDL_GetAudioStatus() == SDL_AUDIO_PLAYING))
135 {
136 loop();
137
138 SDL_Delay(100); /* let it play for awhile. */
139 }
140 #endif
141
142 /* Clean up on signal */
143 SDL_CloseAudio();
144 SDL_FreeWAV(wave.sound);
145 SDL_Quit();
146 return 0;
147 }
148
149 /* vi: set ts=4 sw=4 expandtab: */
150