Change input video from saved video to streaming video for manipulation - matlab

Question

I downloaded this code from MIT's video magnification lab: http://people.csail.mit.edu/mrub/evm/#code
Except it currently only runs on saved videos. We wanted to change it so that we can have a live video set up.
The matlab code is as follows:
dataDir = './data';
resultsDir = 'ResultsSIGGRAPH2012';
mkdir(resultsDir);
inFile = fullfile(dataDir,'face2.mp4');
fprintf('Processing %s\n', inFile);
% Motion
amplify_spatial_lpyr_temporal_butter(inFile,resultsDir,20,80, ...
0.5,10,30, 0);
The amplify_spatial_lpyr_temporal_butter matlab code is:
function amplify_spatial_lpyr_temporal_butter(vidFile, outDir ...
,alpha, lambda_c, fl, fh ...
,samplingRate, chromAttenuation)
[low_a, low_b] = butter(1, fl/samplingRate, 'low');
[high_a, high_b] = butter(1, fh/samplingRate, 'low');
[~,vidName] = fileparts(vidFile);
outName = fullfile(outDir,[vidName '-butter-from-' num2str(fl) '-to-' ...
num2str(fh) '-alpha-' num2str(alpha) '-lambda_c-' num2str(lambda_c) ...
'-chromAtn-' num2str(chromAttenuation) '.avi']);
% Read video
vid = VideoReader(vidFile);
% Extract video info
vidHeight = vid.Height;
vidWidth = vid.Width;
nChannels = 3;
fr = vid.FrameRate;
len = vid.NumberOfFrames;
temp = struct('cdata', ...
zeros(vidHeight, vidWidth, nChannels, 'uint8'), ...
'colormap', []);
startIndex = 1;
endIndex = len-10;
vidOut = VideoWriter(outName);
vidOut.FrameRate = fr;
open(vidOut)
% firstFrame
temp.cdata = read(vid, startIndex);
[rgbframe,~] = frame2im(temp);
rgbframe = im2double(rgbframe);
frame = rgb2ntsc(rgbframe);
[pyr,pind] = buildLpyr(frame(:,:,1),'auto');
pyr = repmat(pyr,[1 3]);
[pyr(:,2),~] = buildLpyr(frame(:,:,2),'auto');
[pyr(:,3),~] = buildLpyr(frame(:,:,3),'auto');
lowpass1 = pyr;
lowpass2 = pyr;
pyr_prev = pyr;
output = rgbframe;
writeVideo(vidOut,im2uint8(output));
nLevels = size(pind,1);
for i=startIndex+1:endIndex
progmeter(i-startIndex,endIndex - startIndex + 1);
temp.cdata = read(vid, i);
[rgbframe,~] = frame2im(temp);
rgbframe = im2double(rgbframe);
frame = rgb2ntsc(rgbframe);
[pyr(:,1),~] = buildLpyr(frame(:,:,1),'auto');
[pyr(:,2),~] = buildLpyr(frame(:,:,2),'auto');
[pyr(:,3),~] = buildLpyr(frame(:,:,3),'auto');
%% temporal filtering
lowpass1 = (-high_b(2) .* lowpass1 + high_a(1).*pyr + ...
high_a(2).*pyr_prev)./high_b(1);
lowpass2 = (-low_b(2) .* lowpass2 + low_a(1).*pyr + ...
low_a(2).*pyr_prev)./low_b(1);
filtered = (lowpass1 - lowpass2);
pyr_prev = pyr;
%% amplify each spatial frequency bands according to Figure 6 of our paper
ind = size(pyr,1);
delta = lambda_c/8/(1+alpha);
% the factor to boost alpha above the bound we have in the
% paper. (for better visualization)
exaggeration_factor = 2;
% compute the representative wavelength lambda for the lowest spatial
% freqency band of Laplacian pyramid
lambda = (vidHeight^2 + vidWidth^2).^0.5/3; % 3 is experimental constant
for l = nLevels:-1:1
indices = ind-prod(pind(l,:))+1:ind;
% compute modified alpha for this level
currAlpha = lambda/delta/8 - 1;
currAlpha = currAlpha*exaggeration_factor;
if (l == nLevels || l == 1) % ignore the highest and lowest frequency band
filtered(indices,:) = 0;
elseif (currAlpha > alpha) % representative lambda exceeds lambda_c
filtered(indices,:) = alpha*filtered(indices,:);
else
filtered(indices,:) = currAlpha*filtered(indices,:);
end
ind = ind - prod(pind(l,:));
% go one level down on pyramid,
% representative lambda will reduce by factor of 2
lambda = lambda/2;
end
%% Render on the input video
output = zeros(size(frame));
output(:,:,1) = reconLpyr(filtered(:,1),pind);
output(:,:,2) = reconLpyr(filtered(:,2),pind);
output(:,:,3) = reconLpyr(filtered(:,3),pind);
output(:,:,2) = output(:,:,2)*chromAttenuation;
output(:,:,3) = output(:,:,3)*chromAttenuation;
output = frame + output;
output = ntsc2rgb(output);
% filtered = rgbframe + filtered.*mask;
output(output > 1) = 1;
output(output < 0) = 0;
writeVideo(vidOut,im2uint8(output));
end
close(vidOut);
end
We are trying to get it to work with a streaming video input, but don't really know where to start. We are somewhat familiar with programming but not so familiar with Matlab and so don't really know where to look for such answers.
Any help would be greatly appreciated.