1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2021 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 */
36typedef 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(). */
42extern void SDL_AddAudioDevice(const int iscapture, const char *name, SDL_AudioSpec *spec, void *handle);
43
44/* Audio targets should call this as devices are removed, so SDL can update
45 its list of available devices. */
46extern 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. */
52extern 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
65typedef 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
97typedef struct SDL_AudioDeviceItem
98{
99 void *handle;
100 char *name;
101 char *original_name;
102 SDL_AudioSpec spec;
103 int dupenum;
104 struct SDL_AudioDeviceItem *next;
105} SDL_AudioDeviceItem;
106
107
108typedef struct SDL_AudioDriver
109{
110 /* * * */
111 /* The name of this audio driver */
112 const char *name;
113
114 /* * * */
115 /* The description of this audio driver */
116 const char *desc;
117
118 SDL_AudioDriverImpl impl;
119
120 /* A mutex for device detection */
121 SDL_mutex *detectionLock;
122 SDL_bool captureDevicesRemoved;
123 SDL_bool outputDevicesRemoved;
124 int outputDeviceCount;
125 int inputDeviceCount;
126 SDL_AudioDeviceItem *outputDevices;
127 SDL_AudioDeviceItem *inputDevices;
128} SDL_AudioDriver;
129
130
131/* Define the SDL audio driver structure */
132struct SDL_AudioDevice
133{
134 /* * * */
135 /* Data common to all devices */
136 SDL_AudioDeviceID id;
137
138 /* The device's current audio specification */
139 SDL_AudioSpec spec;
140
141 /* The callback's expected audio specification (converted vs device's spec). */
142 SDL_AudioSpec callbackspec;
143
144 /* Stream that converts and resamples. NULL if not needed. */
145 SDL_AudioStream *stream;
146
147 /* Current state flags */
148 SDL_atomic_t shutdown; /* true if we are signaling the play thread to end. */
149 SDL_atomic_t enabled; /* true if device is functioning and connected. */
150 SDL_atomic_t paused;
151 SDL_bool iscapture;
152
153 /* Scratch buffer used in the bridge between SDL and the user callback. */
154 Uint8 *work_buffer;
155
156 /* Size, in bytes, of work_buffer. */
157 Uint32 work_buffer_len;
158
159 /* A mutex for locking the mixing buffers */
160 SDL_mutex *mixer_lock;
161
162 /* A thread to feed the audio device */
163 SDL_Thread *thread;
164 SDL_threadID threadid;
165
166 /* Queued buffers (if app not using callback). */
167 SDL_DataQueue *buffer_queue;
168
169 /* * * */
170 /* Data private to this driver */
171 struct SDL_PrivateAudioData *hidden;
172
173 void *handle;
174};
175#undef _THIS
176
177typedef struct AudioBootStrap
178{
179 const char *name;
180 const char *desc;
181 int (*init) (SDL_AudioDriverImpl * impl);
182 int demand_only; /* 1==request explicitly, or it won't be available. */
183} AudioBootStrap;
184
185/* Not all of these are available in a given build. Use #ifdefs, etc. */
186extern AudioBootStrap PIPEWIRE_bootstrap;
187extern AudioBootStrap PULSEAUDIO_bootstrap;
188extern AudioBootStrap ALSA_bootstrap;
189extern AudioBootStrap JACK_bootstrap;
190extern AudioBootStrap SNDIO_bootstrap;
191extern AudioBootStrap NETBSDAUDIO_bootstrap;
192extern AudioBootStrap DSP_bootstrap;
193extern AudioBootStrap QSAAUDIO_bootstrap;
194extern AudioBootStrap SUNAUDIO_bootstrap;
195extern AudioBootStrap ARTS_bootstrap;
196extern AudioBootStrap ESD_bootstrap;
197extern AudioBootStrap NACLAUDIO_bootstrap;
198extern AudioBootStrap NAS_bootstrap;
199extern AudioBootStrap WASAPI_bootstrap;
200extern AudioBootStrap DSOUND_bootstrap;
201extern AudioBootStrap WINMM_bootstrap;
202extern AudioBootStrap PAUDIO_bootstrap;
203extern AudioBootStrap HAIKUAUDIO_bootstrap;
204extern AudioBootStrap COREAUDIO_bootstrap;
205extern AudioBootStrap DISKAUDIO_bootstrap;
206extern AudioBootStrap DUMMYAUDIO_bootstrap;
207extern AudioBootStrap FUSIONSOUND_bootstrap;
208extern AudioBootStrap aaudio_bootstrap;
209extern AudioBootStrap openslES_bootstrap;
210extern AudioBootStrap ANDROIDAUDIO_bootstrap;
211extern AudioBootStrap PSPAUDIO_bootstrap;
212extern AudioBootStrap VITAAUD_bootstrap;
213extern AudioBootStrap EMSCRIPTENAUDIO_bootstrap;
214extern AudioBootStrap OS2AUDIO_bootstrap;
215
216#endif /* SDL_sysaudio_h_ */
217
218/* vi: set ts=4 sw=4 expandtab: */
219