IVideoFrameObserver

The IVideoFrameObserver class.

You can call RegisterVideoFrameObserver to register or unregister an IVideoFrameObserver object.

OnCaptureVideoFrame

Occurs each time the SDK receives a video frame captured by local devices.

public virtual bool OnCaptureVideoFrame(VIDEO_SOURCE_TYPE sourceType, VideoFrame videoFrame)

You can get raw video data collected by the local device through this callback and preprocess it as needed. Once the preprocessing is complete, you can directly modify videoFrame in this callback, and set the return value to true to send the modified video data to the SDK.

Applicable scenarios

  • Preprocess the locally collected video data before it is processed by the SDK. For example, get video data through this callback and process it with filters, watermarks, cropping, rotation, etc.
  • Get information about the locally collected video data before it is processed by the SDK. For example, the original width, height, frame rate of the video frame, etc.

Trigger timing

After the successful registration of the video data observer, each time the SDK captures a video frame.

Restrictions

  • If the video data type you get is RGBA, the SDK does not support processing the data of the alpha channel.
  • It is recommended that you ensure the modified parameters in videoFrame are consistent with the actual situation of the video frames in the video frame buffer. Otherwise, it may cause unexpected rotation, distortion, and other issues in the local preview and remote video display.

Parameters

sourceType
Video source types, including cameras, screens, or media player. See VIDEO_SOURCE_TYPE.
videoFrame
The video frame. See VideoFrame.

Returns

  • true: Sets the SDK to receive the video frame.
  • false: Sets the SDK to discard the video frame.

OnPreEncodeVideoFrame

Occurs each time the SDK receives a video frame before encoding.

public virtual bool OnPreEncodeVideoFrame(VIDEO_SOURCE_TYPE sourceType, VideoFrame videoFrame)

After you successfully register the video frame observer, the SDK triggers this callback each time it receives a video frame. In this callback, you can get the video data before encoding and then process the data according to your particular scenarios.

After processing, you can send the processed video data back to the SDK in this callback.

Attention:
  • To get the video data captured from the second screen before encoding, you need to set POSITION_PRE_ENCODER (1 << 2) as a frame position through the position parameter of the RegisterVideoFrameObserver method.
  • The video data that this callback gets has been preprocessed, with its content cropped and rotated, and the image enhanced.
  • It is recommended that you ensure the modified parameters in videoFrame are consistent with the actual situation of the video frames in the video frame buffer. Otherwise, it may cause unexpected rotation, distortion, and other issues in the local preview and remote video display.

Parameters

sourceType

The type of the video source. See VIDEO_SOURCE_TYPE.

videoFrame
The video frame. See VideoFrame.

Returns

  • true: Sets the SDK to receive the video frame.
  • false: Sets the SDK to discard the video frame.

OnRenderVideoFrame

Occurs each time the SDK receives a video frame sent by the remote user.

public virtual bool OnRenderVideoFrame(string channelId, uint remoteUid, VideoFrame videoFrame)

After you successfully register the video frame observer, the SDK triggers this callback each time it receives a video frame. In this callback, you can get the video data sent from the remote end before rendering, and then process it according to the particular scenarios.

Note: If you use Unity for development, Agora only supports sending video data in YUV format to SDK. Ensure that you set mode as INTPTR when you call the RegisterVideoFrameObserver method to register a video frame observer.

Parameters

remoteUid
The user ID of the remote user who sends the current video frame.
videoFrame
The video frame. See VideoFrame.
channelId
The channel ID.

Returns

  • true: Sets the SDK to receive the video frame.
  • false: Sets the SDK to discard the video frame.