SDL  2.0
SDL_sysaudio.h
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2017 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. */
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 {
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 */
74  Uint8 *(*GetDeviceBuf) (_THIS);
75  int (*CaptureFromDevice) (_THIS, void *buffer, int buflen);
77  void (*PrepareToClose) (_THIS); /**< Called between run and draining wait for playback devices */
81  void (*FreeDeviceHandle) (void *handle); /**< SDL is done with handle from SDL_AddAudioDevice() */
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 */
95 
96 
97 typedef struct SDL_AudioDeviceItem
98 {
99  void *handle;
103 
104 
105 typedef struct SDL_AudioDriver
106 {
107  /* * * */
108  /* The name of this audio driver */
109  const char *name;
110 
111  /* * * */
112  /* The description of this audio driver */
113  const char *desc;
114 
116 
117  /* A mutex for device detection */
126 
127 
128 /* Define the SDL audio driver structure */
130 {
131  /* * * */
132  /* Data common to all devices */
134 
135  /* The device's current audio specification */
137 
138  /* The callback's expected audio specification (converted vs device's spec). */
140 
141  /* Stream that converts and resamples. NULL if not needed. */
143 
144  /* Current state flags */
145  SDL_atomic_t shutdown; /* true if we are signaling the play thread to end. */
146  SDL_atomic_t enabled; /* true if device is functioning and connected. */
149 
150  /* Scratch buffer used in the bridge between SDL and the user callback. */
152 
153  /* Size, in bytes, of work_buffer. */
155 
156  /* A mutex for locking the mixing buffers */
158 
159  /* A thread to feed the audio device */
162 
163  /* Queued buffers (if app not using callback). */
165 
166  /* * * */
167  /* Data private to this driver */
169 
170  void *handle;
171 };
172 #undef _THIS
173 
174 typedef struct AudioBootStrap
175 {
176  const char *name;
177  const char *desc;
178  int (*init) (SDL_AudioDriverImpl * impl);
179  int demand_only; /* 1==request explicitly, or it won't be available. */
181 
182 /* Not all of these are available in a given build. Use #ifdefs, etc. */
208 
209 #endif /* SDL_sysaudio_h_ */
210 
211 /* vi: set ts=4 sw=4 expandtab: */
struct SDL_PrivateAudioData * hidden
Definition: SDL_sysaudio.h:168
AudioBootStrap DSP_bootstrap
AudioBootStrap EMSCRIPTENAUDIO_bootstrap
SDL_AudioDeviceID id
Definition: SDL_sysaudio.h:133
SDL_mutex * mixer_lock
Definition: SDL_sysaudio.h:157
AudioBootStrap NAS_bootstrap
SDL_bool captureDevicesRemoved
Definition: SDL_sysaudio.h:119
SDL_atomic_t enabled
Definition: SDL_sysaudio.h:146
const char * name
Definition: SDL_sysaudio.h:109
void(* DetectDevices)(void)
Definition: SDL_sysaudio.h:67
const char * name
Definition: SDL_sysaudio.h:176
A type representing an atomic integer value. It is a struct so people don&#39;t accidentally use numeric ...
Definition: SDL_atomic.h:195
struct SDL_AudioDeviceItem * next
Definition: SDL_sysaudio.h:100
SDL_atomic_t paused
Definition: SDL_sysaudio.h:147
SDL_atomic_t shutdown
Definition: SDL_sysaudio.h:145
AudioBootStrap DISKAUDIO_bootstrap
AudioBootStrap ESD_bootstrap
void(* ThreadDeinit)(_THIS)
Definition: SDL_sysaudio.h:70
SDL_threadID threadid
Definition: SDL_sysaudio.h:161
AudioBootStrap PSPAUDIO_bootstrap
void(* PlayDevice)(_THIS)
Definition: SDL_sysaudio.h:72
void(* WaitDevice)(_THIS)
Definition: SDL_sysaudio.h:71
AudioBootStrap DUMMYAUDIO_bootstrap
SDL_AudioSpec spec
Definition: SDL_sysaudio.h:136
void SDL_AddAudioDevice(const int iscapture, const char *name, void *handle)
Definition: SDL_audio.c:429
AudioBootStrap COREAUDIO_bootstrap
AudioBootStrap SNDIO_bootstrap
AudioBootStrap HAIKUAUDIO_bootstrap
uint32_t Uint32
Definition: SDL_stdinc.h:181
void(* UnlockDevice)(_THIS)
Definition: SDL_sysaudio.h:80
Uint32 work_buffer_len
Definition: SDL_sysaudio.h:154
GLuint const GLchar * name
SDL_mutex * detectionLock
Definition: SDL_sysaudio.h:118
AudioBootStrap SUNAUDIO_bootstrap
void SDL_RemoveAudioDevice(const int iscapture, void *handle)
Definition: SDL_audio.c:487
static SDL_AudioDeviceID device
Definition: loopwave.c:37
void(* ThreadInit)(_THIS)
Definition: SDL_sysaudio.h:69
EGLImageKHR EGLint EGLint * handle
Definition: eglext.h:937
AudioBootStrap FUSIONSOUND_bootstrap
AudioBootStrap WASAPI_bootstrap
uint8_t Uint8
Definition: SDL_stdinc.h:157
const char * desc
Definition: SDL_sysaudio.h:113
void(* PrepareToClose)(_THIS)
Definition: SDL_sysaudio.h:77
SDL_bool iscapture
Definition: SDL_sysaudio.h:148
AudioBootStrap QSAAUDIO_bootstrap
void(* Deinitialize)(void)
Definition: SDL_sysaudio.h:82
#define _THIS
Definition: SDL_sysaudio.h:37
#define SDL_VARIABLE_LENGTH_ARRAY
Definition: SDL_internal.h:35
void(* LockDevice)(_THIS)
Definition: SDL_sysaudio.h:79
SDL_AudioDeviceItem * outputDevices
Definition: SDL_sysaudio.h:123
AudioBootStrap ANDROIDAUDIO_bootstrap
AudioBootStrap WINMM_bootstrap
AudioBootStrap ALSA_bootstrap
int(* OpenDevice)(_THIS, void *handle, const char *devname, int iscapture)
Definition: SDL_sysaudio.h:68
SDL_bool
Definition: SDL_stdinc.h:139
GLuint buffer
SDL_DataQueue * buffer_queue
Definition: SDL_sysaudio.h:164
SDL_bool outputDevicesRemoved
Definition: SDL_sysaudio.h:120
int(* CaptureFromDevice)(_THIS, void *buffer, int buflen)
Definition: SDL_sysaudio.h:75
void(* CloseDevice)(_THIS)
Definition: SDL_sysaudio.h:78
SDL_AudioDriverImpl impl
Definition: SDL_sysaudio.h:115
void(* FreeDeviceHandle)(void *handle)
Definition: SDL_sysaudio.h:81
Uint32 SDL_AudioDeviceID
Definition: SDL_audio.h:320
void(* FlushCapture)(_THIS)
Definition: SDL_sysaudio.h:76
SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char const char SDL_SCANF_FORMAT_STRING const char return SDL_ThreadFunction const char void return Uint32 return Uint32 void
AudioBootStrap PAUDIO_bootstrap
AudioBootStrap NACLAUDIO_bootstrap
AudioBootStrap NETBSDAUDIO_bootstrap
AudioBootStrap JACK_bootstrap
AudioBootStrap ARTS_bootstrap
void SDL_OpenedAudioDeviceDisconnected(SDL_AudioDevice *device)
Definition: SDL_audio.c:446
AudioBootStrap DSOUND_bootstrap
AudioBootStrap PULSEAUDIO_bootstrap
int(* GetPendingBytes)(_THIS)
Definition: SDL_sysaudio.h:73
const char * desc
Definition: SDL_sysaudio.h:177
SDL_Thread * thread
Definition: SDL_sysaudio.h:160
SDL_AudioSpec callbackspec
Definition: SDL_sysaudio.h:139
AudioBootStrap XAUDIO2_bootstrap
SDL_AudioStream * stream
Definition: SDL_sysaudio.h:142
SDL_AudioDeviceItem * inputDevices
Definition: SDL_sysaudio.h:124
Uint8 * work_buffer
Definition: SDL_sysaudio.h:151
unsigned long SDL_threadID
Definition: SDL_thread.h:49