1 files changed, 56 insertions, 0 deletions
diff --git a/src/multimedia/wasm/qwasmaudiodevice.cpp b/src/multimedia/wasm/qwasmaudiodevice.cpp
new file mode 100644
index 000000000..c87a0ad54
--- /dev/null
+++ b/src/multimedia/wasm/qwasmaudiodevice.cpp
@@ -0,0 +1,56 @@
+// Copyright (C) 2021 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qwasmaudiodevice_p.h"
+#include <emscripten.h>
+#include <emscripten/val.h>
+#include <emscripten/bind.h>
+
+#include <AL/al.h>
+#include <AL/alc.h>
+
+QT_BEGIN_NAMESPACE
+
+QWasmAudioDevice::QWasmAudioDevice(const char *device, const char *desc, bool isDef, QAudioDevice::Mode mode)
+    : QAudioDevicePrivate(device, mode)
+{
+    description = QString::fromUtf8(desc);
+
+    isDefault = isDef;
+    minimumChannelCount = 1;
+    maximumChannelCount = 2;
+    minimumSampleRate = 8000;
+    maximumSampleRate = 96000; // js AudioContext max according to docs
+
+    // native openAL formats
+    supportedSampleFormats.append(QAudioFormat::UInt8);
+    supportedSampleFormats.append(QAudioFormat::Int16);
+
+    // Browsers use 32bit floats as native, but emscripten reccomends checking for the exension.
+    if (alIsExtensionPresent("AL_EXT_float32"))
+        supportedSampleFormats.append(QAudioFormat::Float);
+
+    preferredFormat.setChannelCount(2);
+
+    // FIXME: firefox
+    // An AudioContext was prevented from starting automatically.
+    // It must be created or resumed after a user gesture on the page.
+    emscripten::val audioContext = emscripten::val::global("window")["AudioContext"].new_();
+    if (audioContext == emscripten::val::undefined())
+        audioContext = emscripten::val::global("window")["webkitAudioContext"].new_();
+
+    if (audioContext != emscripten::val::undefined()) {
+        audioContext.call<void>("resume");
+        int sRate = audioContext["sampleRate"].as<int>();
+        audioContext.call<void>("close");
+        preferredFormat.setSampleRate(sRate);
+    }
+
+    auto f = QAudioFormat::Float;
+
+    if (!supportedSampleFormats.contains(f))
+        f = QAudioFormat::Int16;
+    preferredFormat.setSampleFormat(f);
+}
+
+QT_END_NAMESPACE