ivan@138: function [problemData, solutionData] = generateMissingGroupsProblem(xFrame,problemParameters)
ivan@138: %
ivan@138: %
ivan@138: % Usage:
ivan@138: %
ivan@138: %
ivan@138: % Inputs:
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %
ivan@138: % Outputs:
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %          - 
ivan@138: %
ivan@138: % Note that the CVX library is needed.
ivan@138: %
ivan@138: % -------------------
ivan@138: %
ivan@138: % Audio Inpainting toolbox
ivan@138: % Date: June 28, 2011
ivan@138: % By Valentin Emiya, Amir Adler, Maria Jafari
ivan@138: % This code is distributed under the terms of the GNU Public License version 3 (http://www.gnu.org/licenses/gpl.txt).
ivan@138: 
ivan@138: % Generate a clipping problem: normalize and clip a signal.
ivan@138: %
ivan@138: % Usage:
ivan@138: %   [problemData, solutionData] = makeClippedSignal(x,clippingLevel,GR)
ivan@138: %
ivan@138: % Inputs:
ivan@138: %   - x: input signal (may be multichannel)
ivan@138: %   - clippingLevel: clipping level, between 0 and 1
ivan@138: %   - GR (default: false): flag to generate an optional graphical display
ivan@138: %
ivan@138: % Outputs:
ivan@138: %   - problemData.xClipped: clipped signal
ivan@138: %   - problemData.IClipped: boolean vector (same size as problemData.xClipped) that indexes clipped
ivan@138: %   samples
ivan@138: %   - problemData.clipSizes: size of the clipped segments (not necessary
ivan@138: %   for solving the problem)
ivan@138: %   - solutionData.xClean: clean signal (input signal after normalization
ivan@138: %
ivan@138: % Note that the input signal is normalized to 0.9999 (-1 is not allowed in
ivan@138: % wav files) to provide problemData.xClipped and solutionData.xClean.
ivan@138: 
ivan@138: %function [xFrame,xFrameObs,Imiss] = aux_getFrame(xFrame,holeSize,NHoles)%,param,frameParam,kFrame)
ivan@138: 
ivan@138: N = length(xFrame); % frame length
ivan@138: 
ivan@138: % Load frame
ivan@138: % xFrame = wavread(param.wavFiles{frameParam.kFrameFile(kFrame)},frameParam.kFrameBegin(kFrame)+[0,N-1]);
ivan@138: 
ivan@138: % Window
ivan@138: %xFrame = xFrame.*param.wa(N).';
ivan@138: 
ivan@138: % Normalize
ivan@138: xFrame = xFrame/max(abs(xFrame));
ivan@138: 
ivan@138: % Build random measurement matrix with NHoles of length holeSize
ivan@138: [M IMiss] = makeRandomMeasurementMatrix(N,problemParameters.NHoles,problemParameters.holeSize);
ivan@138: xFrameObs = xFrame;
ivan@138: xFrameObs(IMiss) = 0;
ivan@138: 
ivan@138: problemData.x = xFrameObs;
ivan@138: problemData.IMiss = IMiss;
ivan@138: solutionData.xClean = xFrame;
ivan@138: return
ivan@138: 
ivan@138: 
ivan@138: function [M Im] = makeRandomMeasurementMatrix(N,NMissingBlocks,blockSize)
ivan@138: % [M Im] = makeRandomMeasurementMatrix(N,NMissingBlocks,blockSize)
ivan@138: %    Create a random measurement matrix M where NMissingBlocks blocks with 
ivan@138: %    size blockSize each are randomly inserted. The boolean vector Im 
ivan@138: %    indicates the location of the NMissingBlocks*blockSize missing
ivan@138: %    samples.
ivan@138: %    If the number of missing samples is large, there may be very few solutions
ivan@138: %    so that after a few failing attempts, the results is generated in a deterministic
ivan@138: %    way (groups separated by one sample). This happens for example when the number of
ivan@138: %    missing samples is close to half the frame length, for isolated samples (blockSize=1).
ivan@138: 
ivan@138: nTry = 1;
ivan@138: while true
ivan@138:    try
ivan@138:       Im = false(N,1);
ivan@138:       
ivan@138:       possibleStart = 1:N-blockSize+1;
ivan@138:       
ivan@138:       for k=1:NMissingBlocks
ivan@138:          if isempty(possibleStart)
ivan@138:             error('makeRandomMeasurementMatrix:tooMuchMissingSamples',...
ivan@138:                'Too much missing segments');
ivan@138:          end
ivan@138:          I = ceil(rand*(length(possibleStart)-1));
ivan@138:          I = possibleStart(I);
ivan@138:          Im(I+(0:blockSize-1)) = true;
ivan@138:          possibleStart(possibleStart>=I-blockSize & possibleStart<=I+blockSize) = [];
ivan@138:       end
ivan@138:       break
ivan@138:    catch
ivan@138:       fprintf('makeRandomMeasurementMatrix:retry (%d)\n',nTry);
ivan@138:       nTry = nTry+1;
ivan@138:       if nTry>10
ivan@138:             Im = [true(blockSize,NMissingBlocks);false(1,NMissingBlocks)];
ivan@138:             Im = Im(:);
ivan@138:             while length(Im)<N
ivan@138:                N0 = sum(~Im);
ivan@138:                I0 = find(~Im,randi(N0),'first');
ivan@138:                I0 = I0(end);
ivan@138:                Im = [Im(1:I0);false;Im(I0+1:end)];
ivan@138:             end
ivan@138:             Im = circshift(Im,randi(N));
ivan@138:          break;
ivan@138:       end
ivan@138:    end
ivan@138: end
ivan@138: M = eye(N);
ivan@138: M(Im,:) = [];
ivan@138: 
ivan@138: return