src/audio/nacl/SDL_naclaudio.c
author Ryan C. Gordon
Sun, 28 Aug 2016 18:52:25 -0400
changeset 10288 d45b253d1174
parent 10281 2a002e96888f
child 10737 3406a0f8b041
permissions -rw-r--r--
nacl: Patched to compile.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2016 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 */
    48 static void nacl_audio_callback(void* samples, uint32_t buffer_size, PP_TimeDelta latency, void* data) {
    49     SDL_AudioDevice* _this = (SDL_AudioDevice*) data;
    50     
    51     SDL_LockMutex(private->mutex);  /* !!! FIXME: is this mutex necessary? */
    52 
    53     if (SDL_AtomicGet(&_this->enabled) && !SDL_AtomicGet(&_this->paused)) {
    54         if (_this->convert.needed) {
    55             SDL_LockMutex(_this->mixer_lock);
    56             (*_this->spec.callback) (_this->spec.userdata,
    57                                      (Uint8 *) _this->convert.buf,
    58                                      _this->convert.len);
    59             SDL_UnlockMutex(_this->mixer_lock);
    60             SDL_ConvertAudio(&_this->convert);
    61             SDL_memcpy(samples, _this->convert.buf, _this->convert.len_cvt);
    62         } else {
    63             SDL_LockMutex(_this->mixer_lock);
    64             (*_this->spec.callback) (_this->spec.userdata, (Uint8 *) samples, buffer_size);
    65             SDL_UnlockMutex(_this->mixer_lock);
    66         }
    67     } else {
    68         SDL_memset(samples, _this->spec.silence, buffer_size);
    69     }
    70     
    71     SDL_UnlockMutex(private->mutex);
    72 }
    73 
    74 static void NACLAUDIO_CloseDevice(SDL_AudioDevice *device) {
    75     const PPB_Core *core = PSInterfaceCore();
    76     const PPB_Audio *ppb_audio = PSInterfaceAudio();
    77     SDL_PrivateAudioData *hidden = (SDL_PrivateAudioData *) device->hidden;
    78     
    79     ppb_audio->StopPlayback(hidden->audio);
    80     SDL_DestroyMutex(hidden->mutex);
    81     core->ReleaseResource(hidden->audio);
    82 }
    83 
    84 static int
    85 NACLAUDIO_OpenDevice(_THIS, void *handle, const char *devname, int iscapture) {
    86     PP_Instance instance = PSGetInstanceId();
    87     const PPB_Audio *ppb_audio = PSInterfaceAudio();
    88     const PPB_AudioConfig *ppb_audiocfg = PSInterfaceAudioConfig();
    89     
    90     private = (SDL_PrivateAudioData *) SDL_calloc(1, (sizeof *private));
    91     if (private == NULL) {
    92         SDL_OutOfMemory();
    93         return 0;
    94     }
    95     
    96     private->mutex = SDL_CreateMutex();
    97     _this->spec.freq = 44100;
    98     _this->spec.format = AUDIO_S16LSB;
    99     _this->spec.channels = 2;
   100     _this->spec.samples = ppb_audiocfg->RecommendSampleFrameCount(
   101         instance, 
   102         PP_AUDIOSAMPLERATE_44100, 
   103         SAMPLE_FRAME_COUNT);
   104     
   105     /* Calculate the final parameters for this audio specification */
   106     SDL_CalculateAudioSpec(&_this->spec);
   107     
   108     private->audio = ppb_audio->Create(
   109         instance,
   110         ppb_audiocfg->CreateStereo16Bit(instance, PP_AUDIOSAMPLERATE_44100, _this->spec.samples),
   111         nacl_audio_callback, 
   112         _this);
   113     
   114     /* Start audio playback while we are still on the main thread. */
   115     ppb_audio->StartPlayback(private->audio);
   116     
   117     return 1;
   118 }
   119 
   120 static int
   121 NACLAUDIO_Init(SDL_AudioDriverImpl * impl)
   122 {
   123     if (PSGetInstanceId() == 0) {
   124         return 0;
   125     }
   126     
   127     /* Set the function pointers */
   128     impl->OpenDevice = NACLAUDIO_OpenDevice;
   129     impl->CloseDevice = NACLAUDIO_CloseDevice;
   130     impl->OnlyHasDefaultOutputDevice = 1;
   131     impl->ProvidesOwnCallbackThread = 1;
   132     /*
   133      *    impl->WaitDevice = NACLAUDIO_WaitDevice;
   134      *    impl->GetDeviceBuf = NACLAUDIO_GetDeviceBuf;
   135      *    impl->PlayDevice = NACLAUDIO_PlayDevice;
   136      *    impl->Deinitialize = NACLAUDIO_Deinitialize;
   137      */
   138     
   139     return 1;
   140 }
   141 
   142 AudioBootStrap NACLAUDIO_bootstrap = {
   143     NACLAUDIO_DRIVER_NAME, "SDL NaCl Audio Driver",
   144     NACLAUDIO_Init, 0
   145 };
   146 
   147 #endif /* SDL_AUDIO_DRIVER_NACL */
   148 
   149 /* vi: set ts=4 sw=4 expandtab: */