EVP Toolbox
	
	video_read_frame - read a frame from a opened video file
	
Calling Sequence
	im = video_read_frame( opened_handle );

Parameters
	* opened_handle: a return handle from video_open.
	* im : a RGB image NxMx3

Description
	We use FFmpeg. FFmpeg is a complete solution to record, convert and stream audio and video. It includes libavcodec, the leading audio/video codec library. FFmpeg is a charming library. Now we can open almost all type of video file under both Linux and windows. For more information, go to  http://ffmpeg.mplayerhq.hu/
	For each time, you read a frame, the file pointor is moved to next frame.
	video_read_frame will return the last frame if reach end fo file.

Examples
	Here is a example: a simple video player
	
	in = video_open( 'ww.mpg');
	[frame, num ] = video_info(in)
	for i=1:num
		im = video_read_frame(in);
		sleep(30);
		imdraw(im, 0, 0,0,352, 288);
	end
	video_close(in);