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
22 #include "../../SDL_internal.h"
23
24 #if SDL_AUDIO_DRIVER_NACL
25
26 #include "SDL_naclaudio.h"
27
28 #include "SDL_audio.h"
29 #include "SDL_mutex.h"
30 #include "../SDL_audio_c.h"
31 #include "../SDL_audiodev_c.h"
32
33 #include "ppapi/c/pp_errors.h"
34 #include "ppapi/c/pp_instance.h"
35 #include "ppapi_simple/ps.h"
36 #include "ppapi_simple/ps_interface.h"
37 #include "ppapi_simple/ps_event.h"
38
39 /* The tag name used by NACL audio */
40 #define NACLAUDIO_DRIVER_NAME "nacl"
41
42 #define SAMPLE_FRAME_COUNT 4096
43
44 /* Audio driver functions */
45 static void nacl_audio_callback(void* samples, uint32_t buffer_size, PP_TimeDelta latency, void* data);
46
47 /* FIXME: Make use of latency if needed */
nacl_audio_callback(void * stream,uint32_t buffer_size,PP_TimeDelta latency,void * data)48 static void nacl_audio_callback(void* stream, uint32_t buffer_size, PP_TimeDelta latency, void* data) {
49 const int len = (int) buffer_size;
50 SDL_AudioDevice* _this = (SDL_AudioDevice*) data;
51 SDL_AudioCallback callback = _this->callbackspec.callback;
52
53 SDL_LockMutex(private->mutex); /* !!! FIXME: is this mutex necessary? */
54
55 /* Only do something if audio is enabled */
56 if (!SDL_AtomicGet(&_this->enabled) || SDL_AtomicGet(&_this->paused)) {
57 if (_this->stream) {
58 SDL_AudioStreamClear(_this->stream);
59 }
60 SDL_memset(stream, _this->spec.silence, len);
61 return;
62 }
63
64 SDL_assert(_this->spec.size == len);
65
66 if (_this->stream == NULL) { /* no conversion necessary. */
67 SDL_LockMutex(_this->mixer_lock);
68 callback(_this->callbackspec.userdata, stream, len);
69 SDL_UnlockMutex(_this->mixer_lock);
70 } else { /* streaming/converting */
71 const int stream_len = _this->callbackspec.size;
72 while (SDL_AudioStreamAvailable(_this->stream) < len) {
73 callback(_this->callbackspec.userdata, _this->work_buffer, stream_len);
74 if (SDL_AudioStreamPut(_this->stream, _this->work_buffer, stream_len) == -1) {
75 SDL_AudioStreamClear(_this->stream);
76 SDL_AtomicSet(&_this->enabled, 0);
77 break;
78 }
79 }
80
81 const int got = SDL_AudioStreamGet(_this->stream, stream, len);
82 SDL_assert((got < 0) || (got == len));
83 if (got != len) {
84 SDL_memset(stream, _this->spec.silence, len);
85 }
86 }
87
88 SDL_UnlockMutex(private->mutex);
89 }
90
NACLAUDIO_CloseDevice(SDL_AudioDevice * device)91 static void NACLAUDIO_CloseDevice(SDL_AudioDevice *device) {
92 const PPB_Core *core = PSInterfaceCore();
93 const PPB_Audio *ppb_audio = PSInterfaceAudio();
94 SDL_PrivateAudioData *hidden = (SDL_PrivateAudioData *) device->hidden;
95
96 ppb_audio->StopPlayback(hidden->audio);
97 SDL_DestroyMutex(hidden->mutex);
98 core->ReleaseResource(hidden->audio);
99 }
100
101 static int
NACLAUDIO_OpenDevice(_THIS,void * handle,const char * devname,int iscapture)102 NACLAUDIO_OpenDevice(_THIS, void *handle, const char *devname, int iscapture) {
103 PP_Instance instance = PSGetInstanceId();
104 const PPB_Audio *ppb_audio = PSInterfaceAudio();
105 const PPB_AudioConfig *ppb_audiocfg = PSInterfaceAudioConfig();
106
107 private = (SDL_PrivateAudioData *) SDL_calloc(1, (sizeof *private));
108 if (private == NULL) {
109 return SDL_OutOfMemory();
110 }
111
112 private->mutex = SDL_CreateMutex();
113 _this->spec.freq = 44100;
114 _this->spec.format = AUDIO_S16LSB;
115 _this->spec.channels = 2;
116 _this->spec.samples = ppb_audiocfg->RecommendSampleFrameCount(
117 instance,
118 PP_AUDIOSAMPLERATE_44100,
119 SAMPLE_FRAME_COUNT);
120
121 /* Calculate the final parameters for this audio specification */
122 SDL_CalculateAudioSpec(&_this->spec);
123
124 private->audio = ppb_audio->Create(
125 instance,
126 ppb_audiocfg->CreateStereo16Bit(instance, PP_AUDIOSAMPLERATE_44100, _this->spec.samples),
127 nacl_audio_callback,
128 _this);
129
130 /* Start audio playback while we are still on the main thread. */
131 ppb_audio->StartPlayback(private->audio);
132
133 return 0;
134 }
135
136 static int
NACLAUDIO_Init(SDL_AudioDriverImpl * impl)137 NACLAUDIO_Init(SDL_AudioDriverImpl * impl)
138 {
139 if (PSGetInstanceId() == 0) {
140 return 0;
141 }
142
143 /* Set the function pointers */
144 impl->OpenDevice = NACLAUDIO_OpenDevice;
145 impl->CloseDevice = NACLAUDIO_CloseDevice;
146 impl->OnlyHasDefaultOutputDevice = 1;
147 impl->ProvidesOwnCallbackThread = 1;
148 /*
149 * impl->WaitDevice = NACLAUDIO_WaitDevice;
150 * impl->GetDeviceBuf = NACLAUDIO_GetDeviceBuf;
151 * impl->PlayDevice = NACLAUDIO_PlayDevice;
152 * impl->Deinitialize = NACLAUDIO_Deinitialize;
153 */
154
155 return 1;
156 }
157
158 AudioBootStrap NACLAUDIO_bootstrap = {
159 NACLAUDIO_DRIVER_NAME, "SDL NaCl Audio Driver",
160 NACLAUDIO_Init, 0
161 };
162
163 #endif /* SDL_AUDIO_DRIVER_NACL */
164
165 /* vi: set ts=4 sw=4 expandtab: */
166