MediaFrameReader MediaFrameReader MediaFrameReader MediaFrameReader Class

Prerelease. Gets or sets a value that specifies the way that the system should manage frames acquired from a MediaFrameReader when a new frame arrives before the app has finished processing the previous frame.

public : MediaFrameReaderAcquisitionMode AcquisitionMode { get; set; }public MediaFrameReaderAcquisitionMode AcquisitionMode { get; set; }Public ReadWrite Property AcquisitionMode As MediaFrameReaderAcquisitionMode// You can use this property in JavaScript.

Remarks

If this property is set to Realtime, frames that arrive while the app's FrameArrived event handler is executing are dropped. This mode works well for scenarios where processing the most current frame is prioritized, such as real-time computer vision applications.

If this property is set to [Buffered]((https://docs.microsoft.com/uwp/api/windows.media.capture.frames.mediaframereaderacquisitionmode), frames that arrive while the app's FrameArrived event handler is executing are buffered in memory by the system. The FrameArrived event is raised for each buffered frame when the event handler for the previous frame has completed. This mode is intended for apps for which the sequence of frames is critical and for which dropped frames will break the scenario. Note that once the system's memory limit for buffered frames has been reached, no more frames will be acquired until the app processes buffered frames, freeing memory for the acquisition of additional frames.

See Also

MediaFrameReaderAcquisitionMode

Disposes of the object and associated resources.

public : void Close()This member is not implemented in C#This member is not implemented in VB.Net// You can use this method in JavaScript.

Remarks

The Close method is used by Universal Windows app using JavaScript. For apps written using the .NET Framework 4.5 in C# and VB.NET, the Close method is exposed as the Dispose() method on the MediaFrameReader object. For apps written in C++, the Close method will be called when using the delete keyword on the object.

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

This member is not implemented in C++void Dispose()Sub Disposevoid Dispose()

Asynchronously starts the reading of frames from a MediaFrameSource.

public : IAsyncOperation<MediaFrameReaderStartStatus> StartAsync()public IAsyncOperation<MediaFrameReaderStartStatus> StartAsync()Public Function StartAsync() As IAsyncOperation( Of MediaFrameReaderStartStatus )// You can use this method in JavaScript.

Asynchronously stops the reading of frames from a MediaFrameSource.

public : IAsyncAction StopAsync()public IAsyncAction StopAsync()Public Function StopAsync() As IAsyncAction// You can use this method in JavaScript.

Attempts to obtain a MediaFrameReference object representing the latest frame from the MediaFrameSource.

public : MediaFrameReference TryAcquireLatestFrame()public MediaFrameReference TryAcquireLatestFrame()Public Function TryAcquireLatestFrame() As MediaFrameReference// You can use this method in JavaScript.

Remarks

Each MediaFrameReader maintains a circular buffer of MediaFrameReference objects obtained from TryAcquireLatestFrame. After all of the MediaFrameReference objects in the buffer have been used, subsequent calls to TryAcquireLatestFrame will cause the system to call Close (or Dispose in C#) on the oldest buffer object in order to reuse it. Once the object has been disposed, you can no longer use it to access the frame data. For this reason, you should not store the MediaFrameReference object longer than you actually need to process the frame. If your app scenario requires you to keep a reference to the data for longer, you should use one of the APIs provided to get the underlying data. These methods include:

• BufferMediaFrame.Buffer
• VideoMediaFrame.SoftwareBitmap
• VideoMediaFrame.GetVideoFrame
• VideoMediaFrame.CameraIntrinsics It is the responsibility of the app to call Close (or Dispose) on the objects returned by these APIs when they are no longer being used.

Occurs when a new frame arrives from the media frame source associated with the MediaFrameReader.

public : event TypedEventHandler FrameArrived<MediaFrameReader,  MediaFrameArrivedEventArgs>public event TypedEventHandler FrameArrived<MediaFrameReader,  MediaFrameArrivedEventArgs>Public Event FrameArrived<MediaFrameReader,  MediaFrameArrivedEventArgs>// You can use this event in JavaScript.

Remarks

In the handler for the FrameArrived event, call TryAcquireLatestFrame to get a MediaFrameReference representing the latest frame from the media frame source.