SDL_emscriptenaudio.c
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/*
Simple DirectMedia Layer
Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include "../../SDL_internal.h"
#if SDL_AUDIO_DRIVER_EMSCRIPTEN
#include "SDL_audio.h"
#include "SDL_log.h"
#include "../SDL_audio_c.h"
#include "SDL_emscriptenaudio.h"
#include "SDL_assert.h"
#include <emscripten/emscripten.h>
static void
FeedAudioDevice(_THIS, const void *buf, const int buflen)
{
const int framelen = (SDL_AUDIO_BITSIZE(this->spec.format) / 8) * this->spec.channels;
EM_ASM_ARGS({
var numChannels = SDL2.audio.currentOutputBuffer['numberOfChannels'];
for (var c = 0; c < numChannels; ++c) {
var channelData = SDL2.audio.currentOutputBuffer['getChannelData'](c);
if (channelData.length != $1) {
throw 'Web Audio output buffer length mismatch! Destination size: ' + channelData.length + ' samples vs expected ' + $1 + ' samples!';
}
for (var j = 0; j < $1; ++j) {
channelData[j] = HEAPF32[$0 + ((j*numChannels + c) << 2) >> 2]; /* !!! FIXME: why are these shifts here? */
}
}
}, buf, buflen / framelen);
}
static void
HandleAudioProcess(_THIS)
{
SDL_AudioCallback callback = this->callbackspec.callback;
const int stream_len = this->callbackspec.size;
/* Only do something if audio is enabled */
if (!SDL_AtomicGet(&this->enabled) || SDL_AtomicGet(&this->paused)) {
if (this->stream) {
SDL_AudioStreamClear(this->stream);
}
return;
}
if (this->stream == NULL) { /* no conversion necessary. */
SDL_assert(this->spec.size == stream_len);
callback(this->callbackspec.userdata, this->work_buffer, stream_len);
} else { /* streaming/converting */
int got;
while (SDL_AudioStreamAvailable(this->stream) < ((int) this->spec.size)) {
callback(this->callbackspec.userdata, this->work_buffer, stream_len);
if (SDL_AudioStreamPut(this->stream, this->work_buffer, stream_len) == -1) {
SDL_AudioStreamClear(this->stream);
SDL_AtomicSet(&this->enabled, 0);
break;
}
}
got = SDL_AudioStreamGet(this->stream, this->work_buffer, this->spec.size);
SDL_assert((got < 0) || (got == this->spec.size));
if (got != this->spec.size) {
SDL_memset(this->work_buffer, this->spec.silence, this->spec.size);
}
}
FeedAudioDevice(this, this->work_buffer, this->spec.size);
}
static void
HandleCaptureProcess(_THIS)
{
SDL_AudioCallback callback = this->callbackspec.callback;
const int stream_len = this->callbackspec.size;
/* Only do something if audio is enabled */
if (!SDL_AtomicGet(&this->enabled) || SDL_AtomicGet(&this->paused)) {
SDL_AudioStreamClear(this->stream);
return;
}
EM_ASM_ARGS({
var numChannels = SDL2.capture.currentCaptureBuffer.numberOfChannels;
for (var c = 0; c < numChannels; ++c) {
var channelData = SDL2.capture.currentCaptureBuffer.getChannelData(c);
if (channelData.length != $1) {
throw 'Web Audio capture buffer length mismatch! Destination size: ' + channelData.length + ' samples vs expected ' + $1 + ' samples!';
}
if (numChannels == 1) { /* fastpath this a little for the common (mono) case. */
for (var j = 0; j < $1; ++j) {
setValue($0 + (j * 4), channelData[j], 'float');
}
} else {
for (var j = 0; j < $1; ++j) {
setValue($0 + (((j * numChannels) + c) * 4), channelData[j], 'float');
}
}
}
}, this->work_buffer, (this->spec.size / sizeof (float)) / this->spec.channels);
/* okay, we've got an interleaved float32 array in C now. */
if (this->stream == NULL) { /* no conversion necessary. */
SDL_assert(this->spec.size == stream_len);
callback(this->callbackspec.userdata, this->work_buffer, stream_len);
} else { /* streaming/converting */
if (SDL_AudioStreamPut(this->stream, this->work_buffer, this->spec.size) == -1) {
SDL_AtomicSet(&this->enabled, 0);
}
while (SDL_AudioStreamAvailable(this->stream) >= stream_len) {
const int got = SDL_AudioStreamGet(this->stream, this->work_buffer, stream_len);
SDL_assert((got < 0) || (got == stream_len));
if (got != stream_len) {
SDL_memset(this->work_buffer, this->callbackspec.silence, stream_len);
}
callback(this->callbackspec.userdata, this->work_buffer, stream_len); /* Send it to the app. */
}
}
}
static void
EMSCRIPTENAUDIO_CloseDevice(_THIS)
{
EM_ASM_({
if ($0) {
if (SDL2.capture.silenceTimer !== undefined) {
clearTimeout(SDL2.capture.silenceTimer);
}
if (SDL2.capture.stream !== undefined) {
var tracks = SDL2.capture.stream.getAudioTracks();
for (var i = 0; i < tracks.length; i++) {
SDL2.capture.stream.removeTrack(tracks[i]);
}
SDL2.capture.stream = undefined;
}
if (SDL2.capture.scriptProcessorNode !== undefined) {
SDL2.capture.scriptProcessorNode.onaudioprocess = function(audioProcessingEvent) {};
SDL2.capture.scriptProcessorNode.disconnect();
SDL2.capture.scriptProcessorNode = undefined;
}
if (SDL2.capture.mediaStreamNode !== undefined) {
SDL2.capture.mediaStreamNode.disconnect();
SDL2.capture.mediaStreamNode = undefined;
}
if (SDL2.capture.silenceBuffer !== undefined) {
SDL2.capture.silenceBuffer = undefined
}
SDL2.capture = undefined;
} else {
if (SDL2.audio.scriptProcessorNode != undefined) {
SDL2.audio.scriptProcessorNode.disconnect();
SDL2.audio.scriptProcessorNode = undefined;
}
SDL2.audio = undefined;
}
if ((SDL2.audioContext !== undefined) && (SDL2.audio === undefined) && (SDL2.capture === undefined)) {
SDL2.audioContext.close();
SDL2.audioContext = undefined;
}
}, this->iscapture);
#if 0 /* !!! FIXME: currently not used. Can we move some stuff off the SDL2 namespace? --ryan. */
SDL_free(this->hidden);
#endif
}
static int
EMSCRIPTENAUDIO_OpenDevice(_THIS, void *handle, const char *devname, int iscapture)
{
SDL_bool valid_format = SDL_FALSE;
SDL_AudioFormat test_format;
int result;
/* based on parts of library_sdl.js */
/* create context (TODO: this puts stuff in the global namespace...)*/
result = EM_ASM_INT({
if(typeof(SDL2) === 'undefined') {
SDL2 = {};
}
if (!$0) {
SDL2.audio = {};
} else {
SDL2.capture = {};
}
if (!SDL2.audioContext) {
if (typeof(AudioContext) !== 'undefined') {
SDL2.audioContext = new AudioContext();
} else if (typeof(webkitAudioContext) !== 'undefined') {
SDL2.audioContext = new webkitAudioContext();
}
}
return SDL2.audioContext === undefined ? -1 : 0;
}, iscapture);
if (result < 0) {
return SDL_SetError("Web Audio API is not available!");
}
test_format = SDL_FirstAudioFormat(this->spec.format);
while ((!valid_format) && (test_format)) {
switch (test_format) {
case AUDIO_F32: /* web audio only supports floats */
this->spec.format = test_format;
valid_format = SDL_TRUE;
break;
}
test_format = SDL_NextAudioFormat();
}
if (!valid_format) {
/* Didn't find a compatible format :( */
return SDL_SetError("No compatible audio format!");
}
/* Initialize all variables that we clean on shutdown */
#if 0 /* !!! FIXME: currently not used. Can we move some stuff off the SDL2 namespace? --ryan. */
this->hidden = (struct SDL_PrivateAudioData *)
SDL_malloc((sizeof *this->hidden));
if (this->hidden == NULL) {
return SDL_OutOfMemory();
}
SDL_zerop(this->hidden);
#endif
/* limit to native freq */
this->spec.freq = EM_ASM_INT_V({ return SDL2.audioContext.sampleRate; });
SDL_CalculateAudioSpec(&this->spec);
if (iscapture) {
/* The idea is to take the capture media stream, hook it up to an
audio graph where we can pass it through a ScriptProcessorNode
to access the raw PCM samples and push them to the SDL app's
callback. From there, we "process" the audio data into silence
and forget about it. */
/* This should, strictly speaking, use MediaRecorder for capture, but
this API is cleaner to use and better supported, and fires a
callback whenever there's enough data to fire down into the app.
The downside is that we are spending CPU time silencing a buffer
that the audiocontext uselessly mixes into any output. On the
upside, both of those things are not only run in native code in
the browser, they're probably SIMD code, too. MediaRecorder
feels like it's a pretty inefficient tapdance in similar ways,
to be honest. */
EM_ASM_({
var have_microphone = function(stream) {
//console.log('SDL audio capture: we have a microphone! Replacing silence callback.');
if (SDL2.capture.silenceTimer !== undefined) {
clearTimeout(SDL2.capture.silenceTimer);
SDL2.capture.silenceTimer = undefined;
}
SDL2.capture.mediaStreamNode = SDL2.audioContext.createMediaStreamSource(stream);
SDL2.capture.scriptProcessorNode = SDL2.audioContext.createScriptProcessor($1, $0, 1);
SDL2.capture.scriptProcessorNode.onaudioprocess = function(audioProcessingEvent) {
if ((SDL2 === undefined) || (SDL2.capture === undefined)) { return; }
audioProcessingEvent.outputBuffer.getChannelData(0).fill(0.0);
SDL2.capture.currentCaptureBuffer = audioProcessingEvent.inputBuffer;
Runtime.dynCall('vi', $2, [$3]);
};
SDL2.capture.mediaStreamNode.connect(SDL2.capture.scriptProcessorNode);
SDL2.capture.scriptProcessorNode.connect(SDL2.audioContext.destination);
SDL2.capture.stream = stream;
};
var no_microphone = function(error) {
//console.log('SDL audio capture: we DO NOT have a microphone! (' + error.name + ')...leaving silence callback running.');
};
/* we write silence to the audio callback until the microphone is available (user approves use, etc). */
SDL2.capture.silenceBuffer = SDL2.audioContext.createBuffer($0, $1, SDL2.audioContext.sampleRate);
SDL2.capture.silenceBuffer.getChannelData(0).fill(0.0);
var silence_callback = function() {
SDL2.capture.currentCaptureBuffer = SDL2.capture.silenceBuffer;
Runtime.dynCall('vi', $2, [$3]);
};
SDL2.capture.silenceTimer = setTimeout(silence_callback, ($1 / SDL2.audioContext.sampleRate) * 1000);
if ((navigator.mediaDevices !== undefined) && (navigator.mediaDevices.getUserMedia !== undefined)) {
navigator.mediaDevices.getUserMedia({ audio: true, video: false }).then(have_microphone).catch(no_microphone);
} else if (navigator.webkitGetUserMedia !== undefined) {
navigator.webkitGetUserMedia({ audio: true, video: false }, have_microphone, no_microphone);
}
}, this->spec.channels, this->spec.samples, HandleCaptureProcess, this);
} else {
/* setup a ScriptProcessorNode */
EM_ASM_ARGS({
SDL2.audio.scriptProcessorNode = SDL2.audioContext['createScriptProcessor']($1, 0, $0);
SDL2.audio.scriptProcessorNode['onaudioprocess'] = function (e) {
if ((SDL2 === undefined) || (SDL2.audio === undefined)) { return; }
SDL2.audio.currentOutputBuffer = e['outputBuffer'];
Runtime.dynCall('vi', $2, [$3]);
};
SDL2.audio.scriptProcessorNode['connect'](SDL2.audioContext['destination']);
}, this->spec.channels, this->spec.samples, HandleAudioProcess, this);
}
return 0;
}
static int
EMSCRIPTENAUDIO_Init(SDL_AudioDriverImpl * impl)
{
int available;
int capture_available;
/* Set the function pointers */
impl->OpenDevice = EMSCRIPTENAUDIO_OpenDevice;
impl->CloseDevice = EMSCRIPTENAUDIO_CloseDevice;
impl->OnlyHasDefaultOutputDevice = 1;
/* no threads here */
impl->SkipMixerLock = 1;
impl->ProvidesOwnCallbackThread = 1;
/* check availability */
available = EM_ASM_INT_V({
if (typeof(AudioContext) !== 'undefined') {
return 1;
} else if (typeof(webkitAudioContext) !== 'undefined') {
return 1;
}
return 0;
});
if (!available) {
SDL_SetError("No audio context available");
}
capture_available = available && EM_ASM_INT_V({
if ((typeof(navigator.mediaDevices) !== 'undefined') && (typeof(navigator.mediaDevices.getUserMedia) !== 'undefined')) {
return 1;
} else if (typeof(navigator.webkitGetUserMedia) !== 'undefined') {
return 1;
}
return 0;
});
impl->HasCaptureSupport = capture_available ? SDL_TRUE : SDL_FALSE;
impl->OnlyHasDefaultCaptureDevice = capture_available ? SDL_TRUE : SDL_FALSE;
return available;
}
AudioBootStrap EMSCRIPTENAUDIO_bootstrap = {
"emscripten", "SDL emscripten audio driver", EMSCRIPTENAUDIO_Init, 0
};
#endif /* SDL_AUDIO_DRIVER_EMSCRIPTEN */
/* vi: set ts=4 sw=4 expandtab: */
SDL_PrivateAudioData::audio
PP_Resource audio
Definition: SDL_naclaudio.h:38
EMSCRIPTENAUDIO_bootstrap
AudioBootStrap EMSCRIPTENAUDIO_bootstrap
SDL_AudioStreamAvailable
#define SDL_AudioStreamAvailable
Definition: SDL_dynapi_overrides.h:647
SDL_FirstAudioFormat
SDL_AudioFormat SDL_FirstAudioFormat(SDL_AudioFormat format)
Definition: SDL_audio.c:1584
SDL_TRUE
Definition: SDL_stdinc.h:142
result
GLuint64EXT * result
Definition: SDL_opengl_glext.h:9432
e
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 SDL_AssertionHandler void SDL_SpinLock SDL_atomic_t int int return SDL_atomic_t return void void void return void return int return SDL_AudioSpec SDL_AudioSpec return int int return return int SDL_RWops int SDL_AudioSpec Uint8 Uint32 * e
Definition: SDL_dynapi_procs.h:117
SDL_AudioSpec::silence
Uint8 silence
Definition: SDL_audio.h:182
SDL_log.h
available
static int available()
Definition: video.c:356
SDL_AudioStreamGet
#define SDL_AudioStreamGet
Definition: SDL_dynapi_overrides.h:645
SDL_FALSE
Definition: SDL_stdinc.h:141
SDL_AudioDriverImpl::HasCaptureSupport
int HasCaptureSupport
Definition: SDL_sysaudio.h:91
SDL_AudioDriverImpl::ProvidesOwnCallbackThread
int ProvidesOwnCallbackThread
Definition: SDL_sysaudio.h:89
SDL_AudioSpec::samples
Uint16 samples
Definition: SDL_audio.h:183
SDL_AudioFormat
Uint16 SDL_AudioFormat
Audio format flags.
Definition: SDL_audio.h:64
SDL_AudioDriverImpl::OnlyHasDefaultCaptureDevice
int OnlyHasDefaultCaptureDevice
Definition: SDL_sysaudio.h:93
SDL_zerop
#define SDL_zerop(x)
Definition: SDL_stdinc.h:417
SDL_PrivateAudioData
Definition: SDL_alsa_audio.h:33
SDL_NextAudioFormat
SDL_AudioFormat SDL_NextAudioFormat(void)
Definition: SDL_audio.c:1596
spec
SDL_AudioSpec spec
Definition: loopwave.c:31
SDL_emscriptenaudio.h
AudioBootStrap
Definition: SDL_sysaudio.h:175
SDL_AudioDriverImpl::OnlyHasDefaultOutputDevice
int OnlyHasDefaultOutputDevice
Definition: SDL_sysaudio.h:92
SDL_AudioSpec::freq
int freq
Definition: SDL_audio.h:179
handle
EGLImageKHR EGLint EGLint * handle
Definition: eglext.h:937
stream
GLuint GLuint stream
Definition: SDL_opengl_glext.h:1776
SDL_AudioCallback
void(* SDL_AudioCallback)(void *userdata, Uint8 *stream, int len)
Definition: SDL_audio.h:162
SDL_AudioSpec::channels
Uint8 channels
Definition: SDL_audio.h:181
_THIS
#define _THIS
Definition: SDL_alsa_audio.h:31
SDL_free
#define SDL_free
Definition: SDL_dynapi_overrides.h:377
SDL_AUDIO_BITSIZE
#define SDL_AUDIO_BITSIZE(x)
Definition: SDL_audio.h:75
SDL_AudioDriverImpl
Definition: SDL_sysaudio.h:65
SDL_AudioStreamPut
#define SDL_AudioStreamPut
Definition: SDL_dynapi_overrides.h:644
j
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int int in j)
Definition: SDL_x11sym.h:50
c
const GLubyte * c
Definition: SDL_opengl_glext.h:11093
callback
static Uint32 callback(Uint32 interval, void *param)
Definition: testtimer.c:34
paused
int paused
Definition: testoverlay2.c:147
SDL_AudioDriverImpl::SkipMixerLock
int SkipMixerLock
Definition: SDL_sysaudio.h:90
SDL_CalculateAudioSpec
void SDL_CalculateAudioSpec(SDL_AudioSpec *spec)
Definition: SDL_audio.c:1605
buf
GLenum GLuint GLenum GLsizei const GLchar * buf
Definition: SDL_opengl_glext.h:2480
enabled
GLenum GLenum GLsizei const GLuint GLboolean enabled
Definition: SDL_opengl_glext.h:2479
SDL_AudioSpec::size
Uint32 size
Definition: SDL_audio.h:185
SDL_assert
#define SDL_assert(condition)
Definition: SDL_assert.h:169
SDL_AudioDriverImpl::OpenDevice
int(* OpenDevice)(_THIS, void *handle, const char *devname, int iscapture)
Definition: SDL_sysaudio.h:68
NULL
#define NULL
Definition: begin_code.h:164
SDL_OutOfMemory
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
SDL_bool
SDL_bool
Definition: SDL_stdinc.h:139
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:30
SDL_AudioDriverImpl::CloseDevice
void(* CloseDevice)(_THIS)
Definition: SDL_sysaudio.h:79
SDL_audio.h
SDL_AudioSpec::format
SDL_AudioFormat format
Definition: SDL_audio.h:180
SDL_AtomicSet
#define SDL_AtomicSet
Definition: SDL_dynapi_overrides.h:67
SDL_AudioStreamClear
#define SDL_AudioStreamClear
Definition: SDL_dynapi_overrides.h:646
SDL_AtomicGet
#define SDL_AtomicGet
Definition: SDL_dynapi_overrides.h:68
SDL_malloc
#define SDL_malloc
Definition: SDL_dynapi_overrides.h:374
AUDIO_F32
#define AUDIO_F32
Definition: SDL_audio.h:114
SDL_memset
#define SDL_memset
Definition: SDL_dynapi_overrides.h:386
SDL_assert.h