Add example for listing audio and video devices and their properties

Change-Id: I718bfc799b500ca6b931f3fa237f5199c7b6badc
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

3 files changed, 221 insertions, 0 deletions

diff --git a/examples/multimedia/CMakeLists.txt b/examples/multimedia/CMakeLists.txt
index b829c108c..826c08570 100644
--- a/examples/multimedia/CMakeLists.txt
+++ b/examples/multimedia/CMakeLists.txt
@@ -1,6 +1,7 @@
 # Generated from multimedia.pro.
 
 add_subdirectory(audiodecoder)
+add_subdirectory(devices)
 if(TARGET Qt::Widgets)
     add_subdirectory(spectrum)
     add_subdirectory(audiorecorder)
diff --git a/examples/multimedia/devices/CMakeLists.txt b/examples/multimedia/devices/CMakeLists.txt
new file mode 100644
index 000000000..1236a5b48
--- /dev/null
+++ b/examples/multimedia/devices/CMakeLists.txt
@@ -0,0 +1,38 @@
+# Generated from audiodevices.pro.
+
+cmake_minimum_required(VERSION 3.14)
+project(devices LANGUAGES CXX)
+
+set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_AUTOUIC ON)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+  set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/multimedia/devices")
+
+find_package(Qt6 COMPONENTS Core)
+find_package(Qt6 COMPONENTS Gui)
+find_package(Qt6 COMPONENTS Multimedia)
+
+qt_add_executable(devices
+    main.cpp
+)
+set_target_properties(devices PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+target_link_libraries(devices PUBLIC
+    Qt::Core
+    Qt::Gui
+    Qt::Multimedia
+)
+install(TARGETS devices
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)
diff --git a/examples/multimedia/devices/main.cpp b/examples/multimedia/devices/main.cpp
new file mode 100644
index 000000000..ab10a8a45
--- /dev/null
+++ b/examples/multimedia/devices/main.cpp
@@ -0,0 +1,182 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QTextStream>
+#include <QString>
+#include <QAudioFormat>
+
+#include <QAudioDeviceInfo>
+#include <QCameraInfo>
+#include <qmediadevicemanager.h>
+
+#include <stdio.h>
+
+QString formatToString(QAudioFormat::SampleFormat sampleFormat)
+{
+    switch (sampleFormat) {
+    case QAudioFormat::Unknown:
+    case QAudioFormat::NSampleFormats:
+        return "Unknown";
+    case QAudioFormat::UInt8:
+        return "UInt8";
+    case QAudioFormat::Int16:
+        return "Int16";
+    case QAudioFormat::Int32:
+        return "Int32";
+    case QAudioFormat::Float:
+        return "Float";
+    }
+}
+
+QString positionToString(QCameraInfo::Position position)
+{
+    switch (position) {
+        case QCameraInfo::UnspecifiedPosition:
+            return "Unspecified";
+        case QCameraInfo::BackFace:
+            return "BackFace";
+        case QCameraInfo::FrontFace:
+            return "FrontFace";
+    }
+}
+
+void printAudioDeviceInfo(QTextStream &out, const QAudioDeviceInfo &deviceInfo)
+{
+    const auto isDefault = deviceInfo.isDefault() ? "Yes" : "No";
+    const auto preferredFormat = deviceInfo.preferredFormat();
+    const auto ratesRange = deviceInfo.supportedSampleRates();
+    const auto channelsRange = deviceInfo.supportedChannelCounts();
+    const auto supportedFormats = deviceInfo.supportedSampleFormats();
+    out.setFieldWidth(30);
+    out.setFieldAlignment(QTextStream::AlignLeft);
+    out << "Name: " << deviceInfo.description() << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Id: " <<  QString::fromLatin1(deviceInfo.id()) << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Default: " <<  isDefault << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Preferred Format: " << formatToString(preferredFormat.sampleFormat()) << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Preferred Rate: " << preferredFormat.sampleRate() << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Preferred Channels: " << preferredFormat.channelCount() << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Supported Formats: ";
+    for (auto &format: supportedFormats)
+        out << qSetFieldWidth(0) << formatToString(format) << " ";
+    out << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Supported Rates: " << qSetFieldWidth(0) << ratesRange.minimum << " - " << ratesRange.maximum << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Supported Channels: " << qSetFieldWidth(0) << channelsRange.minimum << " - " << channelsRange.maximum << Qt::endl;
+
+    out << Qt::endl;
+}
+
+void printVideoDeviceInfo(QTextStream &out, const QCameraInfo &cameraInfo)
+{
+    const auto isDefault = cameraInfo.isDefault() ? "Yes" : "No";
+    const auto position = cameraInfo.position();
+    const auto photoResolutions = cameraInfo.photoResolutions();
+    const auto videoFormats = cameraInfo.videoFormats();
+
+    out.setFieldWidth(30);
+    out.setFieldAlignment(QTextStream::AlignLeft);
+    out << "Name: " << cameraInfo.description() << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Id: " <<  QString::fromLatin1(cameraInfo.id()) << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Default: " <<  isDefault << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Position: " << positionToString(position) << qSetFieldWidth(0) << Qt::endl;
+    out.setFieldWidth(30);
+    out << "Photo Resolutions: ";
+    for (auto &resolution: photoResolutions) {
+        QString s = QString("%1x%2").arg(resolution.width()).arg(resolution.height());
+        out << qSetFieldWidth(0) << s << ", ";
+    }
+    out.setFieldWidth(10);
+    out << Qt::endl << Qt::endl;
+    out << "Supported Video Formats: " << qSetFieldWidth(0) << Qt::endl;
+    for (auto &format: videoFormats) {
+        out.setFieldWidth(30);
+        QString s = QString("%1x%2").arg(format.resolution().width()).arg(format.resolution().height());
+        out << "Resolution: " << s << qSetFieldWidth(0) << Qt::endl;
+        out.setFieldWidth(30);
+        out << "Frame Rate: " << qSetFieldWidth(0) << "Min:" << format.minFrameRate() << " Max:" << format.maxFrameRate() << Qt::endl;
+    }
+
+    out << Qt::endl;
+
+}
+
+int main()
+{
+    QTextStream out(stdout);
+
+    auto *deviceManager = QMediaDeviceManager::instance();
+    const auto audioInputDevices = deviceManager->audioInputs();
+    const auto audioOutputDevices = deviceManager->audioOutputs();
+    const auto videoInputDevices = deviceManager->videoInputs();
+
+    out << "Audio devices detected: " << Qt::endl;
+    out << Qt::endl << "Input" << Qt::endl;
+    for (auto &deviceInfo: audioInputDevices)
+        printAudioDeviceInfo(out, deviceInfo);
+    out << Qt::endl << "Output" << Qt::endl;
+    for (auto &deviceInfo: audioOutputDevices)
+        printAudioDeviceInfo(out, deviceInfo);
+
+    out << Qt::endl << "Video devices detected: " << Qt::endl;
+    for (auto &cameraInfo: videoInputDevices)
+        printVideoDeviceInfo(out, cameraInfo);
+
+    return 0;
+}