1 files changed, 130 insertions, 0 deletions
diff --git a/src/multimedia/alsa/qalsamediadevices.cpp b/src/multimedia/alsa/qalsamediadevices.cpp
new file mode 100644
index 000000000..9466fa0cd
--- /dev/null
+++ b/src/multimedia/alsa/qalsamediadevices.cpp
@@ -0,0 +1,130 @@
+// 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 "qalsamediadevices_p.h"
+#include "qmediadevices.h"
+#include "qcameradevice_p.h"
+
+#include "private/qalsaaudiosource_p.h"
+#include "private/qalsaaudiosink_p.h"
+#include "private/qalsaaudiodevice_p.h"
+
+#include <alsa/asoundlib.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace {
+
+struct free_char
+{
+    void operator()(char *c) const { ::free(c); }
+};
+
+using unique_str = std::unique_ptr<char, free_char>;
+
+bool operator==(const unique_str &str, std::string_view sv)
+{
+    return std::string_view{ str.get() } == sv;
+}
+bool operator!=(const unique_str &str, std::string_view sv)
+{
+    return !(str == sv);
+}
+
+} // namespace
+
+QAlsaMediaDevices::QAlsaMediaDevices()
+    : QPlatformMediaDevices()
+{
+}
+
+static QList<QAudioDevice> availableDevices(QAudioDevice::Mode mode)
+{
+    QList<QAudioDevice> devices;
+
+    // Create a list of all current audio devices that support mode
+    void **hints;
+    if (snd_device_name_hint(-1, "pcm", &hints) < 0) {
+        qWarning() << "no alsa devices available";
+        return devices;
+    }
+
+    std::string_view filter = (mode == QAudioDevice::Input) ? "Input" : "Output";
+
+    QAlsaAudioDeviceInfo *sysdefault = nullptr;
+
+    auto makeDeviceInfo = [&filter, mode](void *entry) -> QAlsaAudioDeviceInfo * {
+        unique_str name{ snd_device_name_get_hint(entry, "NAME") };
+        if (name && name != "null") {
+            unique_str descr{ snd_device_name_get_hint(entry, "DESC") };
+            unique_str io{ snd_device_name_get_hint(entry, "IOID") };
+
+            if (descr && (!io || (io == filter))) {
+                auto *infop = new QAlsaAudioDeviceInfo{
+                    name.get(),
+                    QString::fromUtf8(descr.get()),
+                    mode,
+                };
+                return infop;
+            }
+        }
+        return nullptr;
+    };
+
+    bool hasDefault = false;
+    void **n = hints;
+    while (*n != NULL) {
+        QAlsaAudioDeviceInfo *infop = makeDeviceInfo(*n++);
+
+        if (infop) {
+            devices.append(infop->create());
+            if (!hasDefault && infop->id.startsWith("default")) {
+                infop->isDefault = true;
+                hasDefault = true;
+            }
+            if (!sysdefault && infop->id.startsWith("sysdefault"))
+                sysdefault = infop;
+        }
+    }
+
+    if (!hasDefault && sysdefault) {
+        // Make "sysdefault" the default device if there is no "default" device exists
+        sysdefault->isDefault = true;
+        hasDefault = true;
+    }
+    if (!hasDefault && devices.size() > 0) {
+        // forcefully declare the first device as "default"
+        QAlsaAudioDeviceInfo *infop = makeDeviceInfo(hints[0]);
+        if (infop) {
+            infop->isDefault = true;
+            devices.prepend(infop->create());
+        }
+    }
+
+    snd_device_name_free_hint(hints);
+    return devices;
+}
+
+QList<QAudioDevice> QAlsaMediaDevices::audioInputs() const
+{
+    return availableDevices(QAudioDevice::Input);
+}
+
+QList<QAudioDevice> QAlsaMediaDevices::audioOutputs() const
+{
+    return availableDevices(QAudioDevice::Output);
+}
+
+QPlatformAudioSource *QAlsaMediaDevices::createAudioSource(const QAudioDevice &deviceInfo,
+                                                           QObject *parent)
+{
+    return new QAlsaAudioSource(deviceInfo.id(), parent);
+}
+
+QPlatformAudioSink *QAlsaMediaDevices::createAudioSink(const QAudioDevice &deviceInfo,
+                                                       QObject *parent)
+{
+    return new QAlsaAudioSink(deviceInfo.id(), parent);
+}
+
+QT_END_NAMESPACE