filepath = 'C:\\bf4 2013-12-07 02-22-08-62.avi';

clc;
try
    v_handle = VideoReader(filepath);
%     video_frames = read(v_handle);
catch err
    error('prog:input', 'Invalid filepath! Enter as ''C:\\filelocation\\file.avi'' ');
end
numFrames = v_handle.NumberOfFrames;

tic;

%Big as possible that can still run in your memory
PartitionSize = 500;

total = zeros(v_handle.Height, v_handle.Width, 3);

for n=1:PartitionSize:numFrames

    stop = n+PartitionSize - 1;
    if(stop > numFrames)
        stop = numFrames;
    end

    A = read(v_handle, [n stop]);

    %Automatically converted to double by MATLAB
    B = sum(A,4);

    total = total + B;

end

total = total./numFrames;

toc