Read 2 frames simultaneously from same video

I want to do some video processing, and i need two frames contiously. the two frames need be right after each other, so i am able to compare them, either being subtracting or else.

clc; clear all;

Video = VideoReader('VID_1.mp4','CurrentTime',11);

opticFlow = opticalFlowLK('NoiseThreshold',0.009);

h = figure;
movegui(h);
hViewPanel = uipanel(h,'Position',[0 0 1 1],'Title','Plot of Optical Flow Vectors');
hPlot = axes(hViewPanel);

while hasFrame(Video)
    frameRGB = readFrame(Video); 
    frameGray = rgb2gray(frameRGB); 
  
    frameRGB2 = readFrame(Video,CurrentTime+1); % I need help here...
     
    flow = estimateFlow(opticFlow,frameGray);
    
   
    imshow(frameRGB2)
    hold on
    plot(points.selectStrongest(50));
    plot(flow,'DecimationFactor',[5 5],'ScaleFactor',100,'Parent',hPlot);
   
    hold off
    pause(10^-3)
end

Answer 1

[Walter Roberson]

frameRGB = readFrame(Video);
while hasFrame(Video)
    frameRGB2 = readFrame(Video);
    %now process like you did
    frameRGB = frameRGB2;   %make current frame the previous frame
end