在 .NET 核心项目中使用来自 UWP api 的 Miracast 无法接收视频帧

Question

我们设法使用 UWP 创建了一个可用的 Miracast 接收器，我们希望在 .NET Core 应用程序中使用此功能。 所以我们按照本指南在 .NET Core 项目中使用 UWP api：

Using UWP apis with WPF and .NET Core

项目运行，我们获得了从智能手机到应用程序的连接，但是我们没有收到来自 MediaPlayer 对象的任何视频帧（与正常工作的原始 UWP 项目不同）

我们观察到在 MediaSource 对象中我们获得了一个 mcrecv url （示例-> mcrecv://192.168.137.247:7236/h-0000000c/192.168.137.1）

但随后使用它的 MediaPlayer 不会触发任何 VideoFrameAvailable 事件。

我们如何解决这个问题？ 以下是我们使用的基本实现：

using System;
using System.Diagnostics;
using System.Windows;
using Windows.Graphics.Imaging;
using Windows.Media.Miracast;
using Windows.Media.Playback;

namespace Miracast_GUI
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MiracastReceiver receiver;
        public MiracastReceiverSession session;
        public MediaPlayer mp;
        public SoftwareBitmap frameServerDest;
        public MiracastReceiverConnection connection;

        public MainWindow()
        {
            InitializeComponent();
            // Starts service
            StartMiracastService();
        }

        public void StartMiracastService()
        {
            receiver = new MiracastReceiver();
            receiver.StatusChanged += Receiver_StatusChanged;
            MiracastReceiverSettings settings = receiver.GetDefaultSettings();

            settings.FriendlyName = "Miracast-Service-Test";
            settings.AuthorizationMethod = MiracastReceiverAuthorizationMethod.None;
            settings.ModelName = receiver.GetDefaultSettings().ModelName;
            settings.ModelNumber = receiver.GetDefaultSettings().ModelNumber;
            settings.RequireAuthorizationFromKnownTransmitters = receiver.GetDefaultSettings().RequireAuthorizationFromKnownTransmitters;

            receiver.DisconnectAllAndApplySettings(settings);

            session = receiver.CreateSession(/*CoreApplication.MainView*/ null);
            session.AllowConnectionTakeover = true;

            session.ConnectionCreated += Session_ConnectionCreated;
            session.MediaSourceCreated += Session_MediaSourceCreated;
            session.Disconnected += Session_Disconnected;

            MiracastReceiverSessionStartResult result = session.Start();
            Debug.WriteLine("Status: " + result.Status);
        }

        private void Session_Disconnected(MiracastReceiverSession sender, MiracastReceiverDisconnectedEventArgs args)
        {
            session.Dispose();
        }

        private void Receiver_StatusChanged(MiracastReceiver sender, object args)
        {
            Debug.WriteLine(receiver.GetStatus().ListeningStatus);
        }

        private void Session_ConnectionCreated(MiracastReceiverSession sender, MiracastReceiverConnectionCreatedEventArgs args)
        {
            connection = args.Connection;
            connection.InputDevices.Keyboard.TransmitInput = true;
            connection.InputDevices.GameController.Mode =
                MiracastReceiverGameControllerDeviceUsageMode.AsMouseAndKeyboard;

            Debug.WriteLine("CONNECTION CREATED");
        }

        private void Session_MediaSourceCreated(MiracastReceiverSession sender, MiracastReceiverMediaSourceCreatedEventArgs args)
        {
            mp = new MediaPlayer
            {
                IsVideoFrameServerEnabled = true,
                AutoPlay = true,
                Source = args.MediaSource,
                RealTimePlayback = true
            };

            mp.VideoFrameAvailable += Mp_VideoFrameAvailable;
            Debug.WriteLine(mp.PlaybackSession.PlaybackState);
            mp.Play();

            Debug.WriteLine("MEDIA SOURCE CREATED");
        }

        private void Mp_VideoFrameAvailable(MediaPlayer sender, object args)
        {
            Console.WriteLine("Received frame...");
        }
    }
}

Answer 1

如果未使用“Internet（客户端和服务器）”功能，UWP 应用的 MediaPlayer 不会触发 VideoFrameAvailable 事件。也许 WPF 项目没有任何能力？因此，wpf 应用程序无法使用其他需要此功能的服务。我不知道如何在 wpf 中使用 uwp 功能。