VideoEncoder.finishSubframe

If multiple subframes are produced for one input frame then use this method for each subframe, except for the last one. Before calling this function, you need to fill frame->output_buffer with the encoded buffer to push.

You must call #[gstvideo.video_encoder.VideoEncoder.finishFrame] for the last sub-frame to tell the encoder that the frame has been fully encoded.

This function will change the metadata of frame and frame->output_buffer will be pushed downstream.