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authMultimediaAssignment2018
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Add psycho for ESH frames

master
Apostolos Fanakis 6 years ago
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e520bcf0ac
commit
eab66a670d
2 changed files with 96 additions and 8 deletions
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  1. 1
      Level_3/AACoder3.m
  2. 103
      Level_3/psycho.m

1
Level_3/AACoder3.m
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@ -103,6 +103,7 @@ function AACSeq3 = AACoder3(fNameIn, fnameAACoded)
frameTypes{i+1}, ...
originalAudioData(prev1FrameStart:prev1FrameStop, 2), ...
originalAudioData(prev2FrameStart:prev2FrameStop, 2));
continue;
[SL, sfcL, GL] = AACquantizer(frameF, frameTypes{i+1}, SMRL);
[SR, sfcR, GR] = AACquantizer(frameF, frameTypes{i+1}, SMRR);
end

103
Level_3/psycho.m
View File

@ -64,9 +64,9 @@ function SMR = psycho(frameT, frameType, frameTprev1, frameTprev2)
tmpSum = tmpz + tmpy;
spreadingShort(tmpy >= -100) = 10 .^ (tmpSum(tmpy >= -100) ./ 10);
hannLong = 0.5 - 0.5 * cos((pi * (0:2047 + 0.5)) / 1024);
hannShort = 0.5 - 0.5 * cos((pi * (0:255 + 0.5)) / 128);
hannLong = 0.5 - 0.5 * cos(pi * ((0:2047) + 0.5) / 1024);
hannShort = 0.5 - 0.5 * cos(pi * ((0:255) + 0.5) / 128);
clearvars tmpx tmpz tmpy
end
@ -122,24 +122,111 @@ function SMR = psycho(frameT, frameType, frameTprev1, frameTprev2)
% Renormalizes values
bandPredictabilityConv = bandPredictabilityConv ./ bandEnergyConv;
bandEnergyConv = bandEnergyConv ./ sum(spreadingLong, 1)';
% Calculates the tonality index
tonalIndex = -0.299 - 0.43 .* log(bandPredictabilityConv);
tonalIndex(tonalIndex < 0) = 0;
tonalIndex(tonalIndex > 1) = 1;
% Calculates SNR and converts from dB to power ratio
signalToNoiseRatio = tonalIndex .* TONE_MASKING_NOISE + ...
(1 - tonalIndex) .* NOISE_MASKING_TONE;
powerRatio = 10 .^ (-signalToNoiseRatio ./ 10);
% Calculates the energy threshold
energyThreshold = bandEnergyConv .* powerRatio;
% Calculates the noise level
qThrN = eps() * 1024 .* 10 .^ (TNSTables.B219a(:, 6) ./ 10);
noiseLevel = max(energyThreshold, qThrN);
SMR = bandEnergy ./ noiseLevel';
else
% Splits the frame into sub-frames
[subFramesT, ~] = buffer(frameT(449:end-448), 256, 128, 'nodelay');
[subFramesTprev1, ~] = buffer(frameTprev1(449:end-448), 256, 128, 'nodelay');
bandEnergy(SHORT_WINDOW_NUMBER_OF_BANDS) = 0;
bandPredictability(SHORT_WINDOW_NUMBER_OF_BANDS) = 0;
qThrN = eps() * 128 .* 10 .^ (TNSTables.B219b(:, 6) ./ 10);
SMR(SHORT_WINDOW_NUMBER_OF_BANDS, 8) = 0;
for subFrameIndex = 1:8
% Applies window to the frames
windowedFrameT = subFramesT(:, subFrameIndex) .* hannShort';
if subFrameIndex == 1
windowedFrameTprev1 = subFramesTprev1(:, 8) .* hannShort';
windowedFrameTprev2 = subFramesTprev1(:, 7) .* hannShort';
elseif subFrameIndex == 2
windowedFrameTprev1 = subFramesT(:, subFrameIndex - 1) .* hannShort';
windowedFrameTprev2 = subFramesTprev1(:, 8) .* hannShort';
else
windowedFrameTprev1 = subFramesT(:, subFrameIndex - 1) .* hannShort';
windowedFrameTprev2 = subFramesT(:, subFrameIndex - 1) .* hannShort';
end
% Calculates the FFT of each frame
frameF = fft(windowedFrameT);
frameFMag = abs(frameF(1:128));
frameFPhase = angle(frameF(1:128));
frameFrameFprev1 = fft(windowedFrameTprev1);
frameFrameFprev1Mag = abs(frameFrameFprev1(1:128));
frameFrameFprev1Phase = angle(frameFrameFprev1(1:128));
frameFrameFprev2 = fft(windowedFrameTprev2);
frameFrameFprev2Mag = abs(frameFrameFprev2(1:128));
frameFrameFprev2Phase = angle(frameFrameFprev2(1:128));
% Calculates the predicted magnitude and phase compontents of each
% frequency
magPred = 2 .* frameFrameFprev1Mag - frameFrameFprev2Mag;
phasePred = 2 .* frameFrameFprev1Phase - frameFrameFprev2Phase;
% Calculates this frame's predictability
framePredictability = sqrt((frameFMag .* cos(frameFPhase) - ...
magPred .* cos(phasePred)) .^ 2 + ...
(frameFMag .* sin(frameFPhase) - ...
magPred .* sin(phasePred)) .^ 2) ./ ...
(frameFMag + abs(magPred));
% Calculates the energy and weighted predictability in the
% threshold calculation partitions
for band = 1:SHORT_WINDOW_NUMBER_OF_BANDS
bandEnergy(band) = sumsqr(frameFMag(TNSTables.B219b(band, 2) + 1: ...
TNSTables.B219b(band, 3) + 1));
bandPredictability(band) = sum(frameFMag( ...
TNSTables.B219b(band, 2) + 1:TNSTables.B219b(band, 3) + 1) .^ 2 .* ...
framePredictability(TNSTables.B219b(band, 2) + 1: ...
TNSTables.B219b(band, 3) + 1));
end
% Convolves the partitioned energy and predictability with the
% spreading function
bandEnergyConv = sum(bandEnergy .* spreadingShort', 2);
bandPredictabilityConv = sum(bandPredictability .* spreadingShort', 2);
% Renormalizes values
bandPredictabilityConv = bandPredictabilityConv ./ bandEnergyConv;
bandEnergyConv = bandEnergyConv ./ sum(spreadingShort, 1)';
% Calculates the tonality index
tonalIndex = -0.299 - 0.43 .* log(bandPredictabilityConv);
tonalIndex(tonalIndex < 0) = 0;
tonalIndex(tonalIndex > 1) = 1;
% Calculates SNR and converts from dB to power ratio
signalToNoiseRatio = tonalIndex .* TONE_MASKING_NOISE + ...
(1 - tonalIndex) .* NOISE_MASKING_TONE;
powerRatio = 10 .^ (-signalToNoiseRatio ./ 10);
% Calculates the energy threshold
energyThreshold = bandEnergyConv .* powerRatio;
% Calculates the noise level
noiseLevel = max(energyThreshold, qThrN);
SMR(:, subFrameIndex) = bandEnergy ./ noiseLevel';
end
end
end

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