通过前置摄像头录制视频 - WP8 - C#

Question

我的 windows phone 应用程序需要从前置摄像头录制视频并通过网络服务将其发送到服务器。

这里，当我尝试从 front-camera 录制视频时，我收到了 mirror inverted video。表示前置摄像头录制180度旋转视频。

我认为可能唯一的解决方案是将录制的视频流向后旋转 180 度。

问题：

在wp8中是否有任何其他解决方案可以通过前置摄像头录制正确的视频？
如果不是，如何将视频流旋转180度？任何 c# API 来做..?

编辑：

这是我正在使用的代码：

XAML VideoBrush

的代码

    <Canvas x:Name="CanvasLayoutRoot" RenderTransformOrigin="0.5 0.5"
            Width="{Binding ActualHeight, ElementName=LayoutRoot}"
            Height="{Binding ActualWidth, ElementName=LayoutRoot}"
            Margin="-160 0 0 0">
        <!--Background="Transparent"-->

        <Canvas.Background>
            <VideoBrush x:Name="videoBrush" />
        </Canvas.Background>
        <Canvas.RenderTransform>
            <RotateTransform x:Name="rt" />
        </Canvas.RenderTransform>

    </Canvas>

正在初始化相机

    public async void InitializeVideoRecorder()
    {
        try
        {
            if (videoCapture == null)
            {
                // below line of code will detect if "Front Camera" is available or not
                // if availble, then open it or it will open "Back Camera"

                videoCapture = await AudioVideoCaptureDevice.OpenAsync(
                    AudioVideoCaptureDevice.AvailableSensorLocations.Contains(CameraSensorLocation.Front) ? CameraSensorLocation.Front : CameraSensorLocation.Back,
                    new Windows.Foundation.Size(640, 480));

                videoCapture.RecordingFailed += videoCapture_RecordingFailed;

                videoCapture.SetProperty(KnownCameraGeneralProperties.EncodeWithOrientation, videoCapture.SensorRotationInDegrees);

                // Initialize the camera if it exists on the phone.
                if (videoCapture != null)
                {
                    videoBrush.SetSource(videoCapture);
                    if (!AudioVideoCaptureDevice.AvailableSensorLocations.Contains(CameraSensorLocation.Front))
                    {
                        rt.Angle = videoCapture.SensorRotationInDegrees;
                    }
                    else
                    {
                        rt.Angle = -(videoCapture.SensorRotationInDegrees);
                    }
                }
                else
                {
                    MessageBox.Show("Unable to load Camera. Please try again later.", App.appName, MessageBoxButton.OK);
                    NavigationService.GoBack();
                }
            }
        }
        catch (Exception ex)
        {
            (new WebServices()).catchExceptions(ex);
            NavigationService.GoBack();
        }
    }

开始视频捕捉

    private async Task StartVideoRecording()
    {
        try
        {
            // Gets the application data folder
            StorageFolder applicationFolder = ApplicationData.Current.LocalFolder;
            StorageFolder transfersFolder = await (await applicationFolder.GetFolderAsync("Shared")).GetFolderAsync("Transfers");

            // Create the file specified in the application data folder
            videoFileName = selectedQue.response.template_id + "_" + selectedQue.response.id + "_" + selectedQue.response.invite_id +".mp4";
            StorageFile storageFile = await transfersFolder.CreateFileAsync(videoFileName, CreationCollisionOption.ReplaceExisting);

            // Open a file stream, ready to write video data
            randomAccessStream = await storageFile.OpenAsync(FileAccessMode.ReadWrite);

            // Video recording to the specified stream
            await videoCapture.StartRecordingToStreamAsync(randomAccessStream);
            isRecordingStarted = true;

            //timer = "0:00";
            tbTimer.Text = "0:00";
            dt.Start();
        }
        catch (Exception ex)
        {
            (new WebServices()).catchExceptions(ex);
        }
    }

Answer 1

这在过去对我有用，它只是我编写代码以满足功能要求的条形码扫描器应用程序。我将变换放在 <VideoBrush> 上。

<Grid x:Name="ContentPanel" Margin="12,0,12,0">
    <Canvas x:Name="cam_canvas" Width="480" Height="480">                
        <Canvas.Background>
            <VideoBrush x:Name="cam_video_brush" Stretch="None">
                <VideoBrush.RelativeTransform>
                    <CompositeTransform Rotation="90" CenterX="0.5" CenterY="0.5" />
                </VideoBrush.RelativeTransform>
            </VideoBrush>
        </Canvas.Background>
    </Canvas>
</Grid>

Answer 2

经过 24 小时的努力，我终于通过以下解决方案解决了我的问题。

下面是导致视频旋转问题的代码行。

videoCapture.SetProperty(KnownCameraGeneralProperties.EncodeWithOrientation, videoCapture.SensorRotationInDegrees);

这里videoCapture是AudioVideoCaptureDevice的对象

使用前置摄像头时，我们需要反转cameraSensor的旋转。

因此，我在 videoCapture.SetProperty 这行代码中使用了上面相同的代码（有问题提到的）并进行了一点小小的修改。正确的代码行如下。

videoCapture.SetProperty(KnownCameraGeneralProperties.EncodeWithOrientation, -(videoCapture.SensorRotationInDegrees));

我只是在 videoCapture.SensorRotationInDegrees 之前加了一个减号 (-) 来反转它。

希望对大家有所帮助..

通过前置摄像头录制视频 - WP8 - C#

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