Question

我的应用程序从另一台计算机的套接字接收USB相机帧流：Windows 10 UWP应用程序从USB相机读取格式为ARGB32的帧。

我想在iPad上显示每一帧，以获得实时取景。

我认为ImageView控件是最好的。

框架的来源是Windows 10上的.NET UWP MediaFrameReader，它来自Logitech HD1080p USB网络摄像头。

有关在Windows计算机上创建框架并将其发送到iPad插槽之前的更多详细信息...

WINDOWS 10上的此代码从相机接收到帧...

        private void Reader_FrameArrived(MediaFrameReader sender, MediaFrameArrivedEventArgs args)
    {

        // Update GUI frame count:
        SDKTemplate.Scenario1_DisplayDepthColorIR.present_frame_count++;

        // TryAcquireLatestFrame will return the latest frame that has not yet been acquired.
        // This can return null if there is no such frame, or if the reader is not in the
        // "Started" state. The latter can occur if a FrameArrived event was in flight
        // when the reader was stopped.
        //using (MediaFrameReference frame = sender.TryAcquireLatestFrame())
        using (MediaFrameReference frame = sender.TryAcquireLatestFrame())
        {
                // Display locally:
                _frameRenderer.ProcessFrame(frame);
        }
    }

此代码准备框架将从WINDOWS发送到IPAD插座...

        public void ProcessFrame( MediaFrameReference frame)
    {
        var softwareBitmap = FrameRenderer.ConvertToDisplayableImage(frame?.VideoMediaFrame);

        if (softwareBitmap != null)
        {
                ++arrived_frames;
            uint frame_size_bytes = frame.BufferMediaFrame.Buffer.Length;
            // Swap the processed frame to _backBuffer and trigger UI thread to render it
            softwareBitmap = Interlocked.Exchange(ref _backBuffer, softwareBitmap);

            // UI thread always reset _backBuffer before using it.  Unused bitmap should be disposed.
            softwareBitmap?.Dispose();

            ////////////////////////   DISPLAY FRAME LOCALLY   /////////////////////////

            // Changes to xaml ImageElement must happen in UI thread through Dispatcher
            var task = _imageElement.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
                async () =>
                {
                    // Don't let two copies of this task run at the same time.
                    if (_taskRunning)
                    {
                        return;
                    }
                    _taskRunning = true;

                    // Keep draining frames from the backbuffer until the backbuffer is empty.
                    SoftwareBitmap latestBitmap;
                    while ((latestBitmap = Interlocked.Exchange(ref _backBuffer, null)) != null)
                    {
                        var imageSource = (SoftwareBitmapSource)_imageElement.Source;
                        await imageSource.SetBitmapAsync(latestBitmap);

                        SDKTemplate.SOURCE.Frames_To_iPad.send_frame_packet( latestBitmap, frame_size_bytes );

                        latestBitmap.Dispose();
                    }

                    _taskRunning = false;
                });

            ////////////////////////////  SEND TO IPAD   //////////////////////////////





        }
    }

Answer 1

您可以尝试在每次接收到新帧时设置UIImageView的Image属性，但是我怀疑这种转换是否能够足够快地进行以使视频流畅显示，因为您需要进行转换您可以将每个帧分配给UIImage属性，然后才能将其分配给Image属性。

我只是使用本地HD大小的图像进行了快速测试，它的跟踪似乎确实非常流畅。图像是存储在应用程序捆绑包中的PNG图像，我不确定从插槽中接收图像时将采用哪种格式。

如何在iPad上的Xamarin iOS ImageView中显示相机镜框？

1 个答案: