Raw video processing

In certain scenarios, it may be necessary to process raw video captured through the camera and microphone to achieve desired functionality or enhance the user experience. Video SDK provides the capability to pre-process and post-process the captured video data, allowing for the implementation of custom playback effects.

Video SDK enables you to pre-process the captured video frames before sending the data to the encoder or perform post-processing on the received video frames after sending the data to the decoder.

The following figure shows the video data processing flow in the SDK video module.

• Position (2) corresponds to the onCaptureVideoFrame callback.
• Position (3) corresponds to the onPreEncodeVideoFrame callback.
• Position (4) corresponds to theonRenderVideoFrame callback.

Ensure that you have implemented the SDK quickstart in your project.

To implement raw video data functionality in your project, refer to the following steps:

1. Before joining the channel, create an IVideoFrameObserver object and register the video observer by calling the registerVideoFrameObserver method.

   
   

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   int ret = engine.registerVideoFrameObserver(iVideoFrameObserver);

   
   

2. Implement the onCaptureVideoFrame and onRenderVideoFrame callbacks. After obtaining the video data, you can process it according to your specific scenario.

   Caution

   When modifying parameters in a VideoFrame, ensure that the updated parameters match the actual video frame in the buffer. Failure to do so may result in unexpected rotation or distortion in both the local preview and the remote video.

   
   

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   private final IVideoFrameObserver iVideoFrameObserver = new IVideoFrameObserver() {

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   @Override

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   public boolean onCaptureVideoFrame(VideoFrame videoFrame) {

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   Log.i(TAG, "OnEncodedVideoImageReceived" + Thread.currentThread().getName());

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   if (isSnapshot) {

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   isSnapshot = false;

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   // Get the image bitmap

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   VideoFrame.Buffer buffer = videoFrame.getBuffer();

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   VideoFrame.I420Buffer i420Buffer = buffer.toI420();

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   int width = i420Buffer.getWidth();

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   int height = i420Buffer.getHeight();

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   ByteBuffer bufferY = i420Buffer.getDataY();

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   ByteBuffer bufferU = i420Buffer.getDataU();

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   ByteBuffer bufferV = i420Buffer.getDataV();

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   byte[] i420 = YUVUtils.toWrappedI420(bufferY, bufferU, bufferV, width, height);

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   Bitmap bitmap = YUVUtils.NV21ToBitmap(getContext(),

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   YUVUtils.I420ToNV21(i420, width, height),

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   width,

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   height);

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   Matrix matrix = new Matrix();

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   matrix.setRotate(270);

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   // Rotate around the center

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   Bitmap newBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, false);

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   // Save to file

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   saveBitmap2Gallery(newBitmap);

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   bitmap.recycle();

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   i420Buffer.release();

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   }

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   return false;

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   }

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   @Override

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   public boolean onScreenCaptureVideoFrame(VideoFrame videoFrame) {

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   return false;

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   }

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   @Override

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   public boolean onMediaPlayerVideoFrame(VideoFrame videoFrame, int i) {

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   return false;

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   }

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   @Override

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   public boolean onRenderVideoFrame(String s, int i, VideoFrame videoFrame) {

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   return false;

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   }

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   @Override

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   public int getVideoFrameProcessMode() {

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   return 0;

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   }

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   @Override

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   public int getVideoFormatPreference() {

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   return 1;

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   }

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   @Override

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   public int getRotationApplied() {

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   return 0;

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   }

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   @Override

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   public boolean getMirrorApplied() {

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   return false;

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   }

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   };

   
   

This section contains information that completes the information in this page, or points you to documentation that explains other aspects to this product.

Agora provides an open source sample project ProcessRawData on GitHub. Download it or view the source code for a more detailed example.

• registerVideoFrameObserver
• registerVideoEncodedFrameObserver
• onCaptureVideoFrame
• onRenderVideoFrame
• getVideoFrameProcessMode
• onEncodedVideoFrameReceived