1 /* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org> 4 5 This software is provided 'as-is', without any express or implied 6 warranty. In no event will the authors be held liable for any damages 7 arising from the use of this software. 8 9 Permission is granted to anyone to use this software for any purpose, 10 including commercial applications, and to alter it and redistribute it 11 freely, subject to the following restrictions: 12 13 1. The origin of this software must not be misrepresented; you must not 14 claim that you wrote the original software. If you use this software 15 in a product, an acknowledgment in the product documentation would be 16 appreciated but is not required. 17 2. Altered source versions must be plainly marked as such, and must not be 18 misrepresented as being the original software. 19 3. This notice may not be removed or altered from any source distribution. 20 */ 21 #include "../SDL_internal.h" 22 23 #ifndef SDL_sysaudio_h_ 24 #define SDL_sysaudio_h_ 25 26 #include "SDL_mutex.h" 27 #include "SDL_thread.h" 28 #include "../SDL_dataqueue.h" 29 #include "./SDL_audio_c.h" 30 31 /* !!! FIXME: These are wordy and unlocalized... */ 32 #define DEFAULT_OUTPUT_DEVNAME "System audio output device" 33 #define DEFAULT_INPUT_DEVNAME "System audio capture device" 34 35 /* The SDL audio driver */ 36 typedef struct SDL_AudioDevice SDL_AudioDevice; 37 #define _THIS SDL_AudioDevice *_this 38 39 /* Audio targets should call this as devices are added to the system (such as 40 a USB headset being plugged in), and should also be called for 41 for every device found during DetectDevices(). */ 42 extern void SDL_AddAudioDevice(const int iscapture, const char *name, void *handle); 43 44 /* Audio targets should call this as devices are removed, so SDL can update 45 its list of available devices. */ 46 extern void SDL_RemoveAudioDevice(const int iscapture, void *handle); 47 48 /* Audio targets should call this if an opened audio device is lost while 49 being used. This can happen due to i/o errors, or a device being unplugged, 50 etc. If the device is totally gone, please also call SDL_RemoveAudioDevice() 51 as appropriate so SDL's list of devices is accurate. */ 52 extern void SDL_OpenedAudioDeviceDisconnected(SDL_AudioDevice *device); 53 54 /* This is the size of a packet when using SDL_QueueAudio(). We allocate 55 these as necessary and pool them, under the assumption that we'll 56 eventually end up with a handful that keep recycling, meeting whatever 57 the app needs. We keep packing data tightly as more arrives to avoid 58 wasting space, and if we get a giant block of data, we'll split them 59 into multiple packets behind the scenes. My expectation is that most 60 apps will have 2-3 of these in the pool. 8k should cover most needs, but 61 if this is crippling for some embedded system, we can #ifdef this. 62 The system preallocates enough packets for 2 callbacks' worth of data. */ 63 #define SDL_AUDIOBUFFERQUEUE_PACKETLEN (8 * 1024) 64 65 typedef struct SDL_AudioDriverImpl 66 { 67 void (*DetectDevices) (void); 68 int (*OpenDevice) (_THIS, void *handle, const char *devname, int iscapture); 69 void (*ThreadInit) (_THIS); /* Called by audio thread at start */ 70 void (*ThreadDeinit) (_THIS); /* Called by audio thread at end */ 71 void (*BeginLoopIteration)(_THIS); /* Called by audio thread at top of loop */ 72 void (*WaitDevice) (_THIS); 73 void (*PlayDevice) (_THIS); 74 Uint8 *(*GetDeviceBuf) (_THIS); 75 int (*CaptureFromDevice) (_THIS, void *buffer, int buflen); 76 void (*FlushCapture) (_THIS); 77 void (*PrepareToClose) (_THIS); /**< Called between run and draining wait for playback devices */ 78 void (*CloseDevice) (_THIS); 79 void (*LockDevice) (_THIS); 80 void (*UnlockDevice) (_THIS); 81 void (*FreeDeviceHandle) (void *handle); /**< SDL is done with handle from SDL_AddAudioDevice() */ 82 void (*Deinitialize) (void); 83 84 /* !!! FIXME: add pause(), so we can optimize instead of mixing silence. */ 85 86 /* Some flags to push duplicate code into the core and reduce #ifdefs. */ 87 /* !!! FIXME: these should be SDL_bool */ 88 int ProvidesOwnCallbackThread; 89 int SkipMixerLock; 90 int HasCaptureSupport; 91 int OnlyHasDefaultOutputDevice; 92 int OnlyHasDefaultCaptureDevice; 93 int AllowsArbitraryDeviceNames; 94 } SDL_AudioDriverImpl; 95 96 97 typedef struct SDL_AudioDeviceItem 98 { 99 void *handle; 100 char *name; 101 char *original_name; 102 int dupenum; 103 struct SDL_AudioDeviceItem *next; 104 } SDL_AudioDeviceItem; 105 106 107 typedef struct SDL_AudioDriver 108 { 109 /* * * */ 110 /* The name of this audio driver */ 111 const char *name; 112 113 /* * * */ 114 /* The description of this audio driver */ 115 const char *desc; 116 117 SDL_AudioDriverImpl impl; 118 119 /* A mutex for device detection */ 120 SDL_mutex *detectionLock; 121 SDL_bool captureDevicesRemoved; 122 SDL_bool outputDevicesRemoved; 123 int outputDeviceCount; 124 int inputDeviceCount; 125 SDL_AudioDeviceItem *outputDevices; 126 SDL_AudioDeviceItem *inputDevices; 127 } SDL_AudioDriver; 128 129 130 /* Define the SDL audio driver structure */ 131 struct SDL_AudioDevice 132 { 133 /* * * */ 134 /* Data common to all devices */ 135 SDL_AudioDeviceID id; 136 137 /* The device's current audio specification */ 138 SDL_AudioSpec spec; 139 140 /* The callback's expected audio specification (converted vs device's spec). */ 141 SDL_AudioSpec callbackspec; 142 143 /* Stream that converts and resamples. NULL if not needed. */ 144 SDL_AudioStream *stream; 145 146 /* Current state flags */ 147 SDL_atomic_t shutdown; /* true if we are signaling the play thread to end. */ 148 SDL_atomic_t enabled; /* true if device is functioning and connected. */ 149 SDL_atomic_t paused; 150 SDL_bool iscapture; 151 152 /* Scratch buffer used in the bridge between SDL and the user callback. */ 153 Uint8 *work_buffer; 154 155 /* Size, in bytes, of work_buffer. */ 156 Uint32 work_buffer_len; 157 158 /* A mutex for locking the mixing buffers */ 159 SDL_mutex *mixer_lock; 160 161 /* A thread to feed the audio device */ 162 SDL_Thread *thread; 163 SDL_threadID threadid; 164 165 /* Queued buffers (if app not using callback). */ 166 SDL_DataQueue *buffer_queue; 167 168 /* * * */ 169 /* Data private to this driver */ 170 struct SDL_PrivateAudioData *hidden; 171 172 void *handle; 173 }; 174 #undef _THIS 175 176 typedef struct AudioBootStrap 177 { 178 const char *name; 179 const char *desc; 180 int (*init) (SDL_AudioDriverImpl * impl); 181 int demand_only; /* 1==request explicitly, or it won't be available. */ 182 } AudioBootStrap; 183 184 /* Not all of these are available in a given build. Use #ifdefs, etc. */ 185 extern AudioBootStrap PULSEAUDIO_bootstrap; 186 extern AudioBootStrap ALSA_bootstrap; 187 extern AudioBootStrap JACK_bootstrap; 188 extern AudioBootStrap SNDIO_bootstrap; 189 extern AudioBootStrap NETBSDAUDIO_bootstrap; 190 extern AudioBootStrap DSP_bootstrap; 191 extern AudioBootStrap QSAAUDIO_bootstrap; 192 extern AudioBootStrap SUNAUDIO_bootstrap; 193 extern AudioBootStrap ARTS_bootstrap; 194 extern AudioBootStrap ESD_bootstrap; 195 extern AudioBootStrap NACLAUDIO_bootstrap; 196 extern AudioBootStrap NAS_bootstrap; 197 extern AudioBootStrap WASAPI_bootstrap; 198 extern AudioBootStrap DSOUND_bootstrap; 199 extern AudioBootStrap WINMM_bootstrap; 200 extern AudioBootStrap PAUDIO_bootstrap; 201 extern AudioBootStrap HAIKUAUDIO_bootstrap; 202 extern AudioBootStrap COREAUDIO_bootstrap; 203 extern AudioBootStrap DISKAUDIO_bootstrap; 204 extern AudioBootStrap DUMMYAUDIO_bootstrap; 205 extern AudioBootStrap FUSIONSOUND_bootstrap; 206 extern AudioBootStrap openslES_bootstrap; 207 extern AudioBootStrap ANDROIDAUDIO_bootstrap; 208 extern AudioBootStrap PSPAUDIO_bootstrap; 209 extern AudioBootStrap EMSCRIPTENAUDIO_bootstrap; 210 extern AudioBootStrap AOSAUDIO_bootstrap; 211 212 #endif /* SDL_sysaudio_h_ */ 213 214 /* vi: set ts=4 sw=4 expandtab: */ 215