test/testaudiohotplug.c
author Ryan C. Gordon <icculus@icculus.org>
Mon, 16 Mar 2015 02:11:39 -0400
changeset 9393 ed79a66e57e5
child 9402 bd133a872458
permissions -rw-r--r--
Initial work on audio device hotplug support.

This fills in the core pieces and fully implements it for Mac OS X.

Most other platforms, at the moment, will report a disconnected device if
it fails to write audio, but don't notice if the system's device list changed
at all.
     1 /*
     2   Copyright (C) 1997-2014 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 test hotplugging of audio devices */
    14 
    15 #include "SDL_config.h"
    16 
    17 #include <stdio.h>
    18 #include <stdlib.h>
    19 
    20 #if HAVE_SIGNAL_H
    21 #include <signal.h>
    22 #endif
    23 
    24 #ifdef __EMSCRIPTEN__
    25 #include <emscripten/emscripten.h>
    26 #endif
    27 
    28 #include "SDL.h"
    29 
    30 static SDL_AudioSpec spec;
    31 static Uint8 *sound = NULL;     /* Pointer to wave data */
    32 static Uint32 soundlen = 0;     /* Length of wave data */
    33 
    34 static int posindex = 0;
    35 static Uint32 positions[64];
    36 
    37 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
    38 static void
    39 quit(int rc)
    40 {
    41     SDL_Quit();
    42     exit(rc);
    43 }
    44 
    45 void SDLCALL
    46 fillerup(void *_pos, Uint8 * stream, int len)
    47 {
    48     Uint32 pos = *((Uint32 *) _pos);
    49     Uint8 *waveptr;
    50     int waveleft;
    51 
    52     /* Set up the pointers */
    53     waveptr = sound + pos;
    54     waveleft = soundlen - pos;
    55 
    56     /* Go! */
    57     while (waveleft <= len) {
    58         SDL_memcpy(stream, waveptr, waveleft);
    59         stream += waveleft;
    60         len -= waveleft;
    61         waveptr = sound;
    62         waveleft = soundlen;
    63         pos = 0;
    64     }
    65     SDL_memcpy(stream, waveptr, len);
    66     pos += len;
    67     *((Uint32 *) _pos) = pos;
    68 }
    69 
    70 static int done = 0;
    71 void
    72 poked(int sig)
    73 {
    74     done = 1;
    75 }
    76 
    77 static void
    78 iteration()
    79 {
    80     SDL_Event e;
    81     SDL_AudioDeviceID dev;
    82     while (SDL_PollEvent(&e)) {
    83         if (e.type == SDL_QUIT) {
    84             done = 1;
    85         } else if (e.type == SDL_AUDIODEVICEADDED) {
    86             const char *name = SDL_GetAudioDeviceName(e.adevice.which, 0);
    87             SDL_Log("New %s audio device: %s\n", e.adevice.iscapture ? "capture" : "output", name);
    88             if (!e.adevice.iscapture) {
    89                 positions[posindex] = 0;
    90                 spec.userdata = &positions[posindex++];
    91                 spec.callback = fillerup;
    92                 dev = SDL_OpenAudioDevice(name, 0, &spec, NULL, 0);
    93                 if (!dev) {
    94                     SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't open '%s': %s\n", name, SDL_GetError());
    95                 } else {
    96                     SDL_Log("Opened '%s' as %u\n", name, (unsigned int) dev);
    97                     SDL_PauseAudioDevice(dev, 0);
    98                 }
    99             }
   100         } else if (e.type == SDL_AUDIODEVICEREMOVED) {
   101             dev = (SDL_AudioDeviceID) e.adevice.which;
   102             SDL_Log("%s device %u removed.\n", e.adevice.iscapture ? "capture" : "output", (unsigned int) dev);
   103             SDL_CloseAudioDevice(dev);
   104         }
   105     }
   106 }
   107 
   108 #ifdef __EMSCRIPTEN__
   109 void
   110 loop()
   111 {
   112     if(done)
   113         emscripten_cancel_main_loop();
   114     else
   115         iteration();
   116 }
   117 #endif
   118 
   119 int
   120 main(int argc, char *argv[])
   121 {
   122     int i;
   123     char filename[4096];
   124 
   125 	/* Enable standard application logging */
   126 	SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
   127 
   128     /* Load the SDL library */
   129     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0) {
   130         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
   131         return (1);
   132     }
   133 
   134     SDL_CreateWindow("testaudiohotplug", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, 0);
   135 
   136     if (argc > 1) {
   137         SDL_strlcpy(filename, argv[1], sizeof(filename));
   138     } else {
   139         SDL_strlcpy(filename, "sample.wav", sizeof(filename));
   140     }
   141     /* Load the wave file into memory */
   142     if (SDL_LoadWAV(filename, &spec, &sound, &soundlen) == NULL) {
   143         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", filename, SDL_GetError());
   144         quit(1);
   145     }
   146 
   147 #if HAVE_SIGNAL_H
   148     /* Set the signals */
   149 #ifdef SIGHUP
   150     signal(SIGHUP, poked);
   151 #endif
   152     signal(SIGINT, poked);
   153 #ifdef SIGQUIT
   154     signal(SIGQUIT, poked);
   155 #endif
   156     signal(SIGTERM, poked);
   157 #endif /* HAVE_SIGNAL_H */
   158 
   159     /* Show the list of available drivers */
   160     SDL_Log("Available audio drivers:");
   161     for (i = 0; i < SDL_GetNumAudioDrivers(); ++i) {
   162 		SDL_Log("%i: %s", i, SDL_GetAudioDriver(i));
   163     }
   164 
   165     SDL_Log("Using audio driver: %s\n", SDL_GetCurrentAudioDriver());
   166 
   167 #ifdef __EMSCRIPTEN__
   168     emscripten_set_main_loop(loop, 0, 1);
   169 #else
   170     while (!done) {
   171         SDL_Delay(100);
   172         iteration();
   173     }
   174 #endif
   175 
   176     /* Clean up on signal */
   177     SDL_Quit();
   178     SDL_FreeWAV(sound);
   179     return (0);
   180 }
   181 
   182 /* vi: set ts=4 sw=4 expandtab: */