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Init psycho

master
Apostolos Fanakis 6 years ago
parent
commit
9a44f99a4d
  1. 22
      Level_3/AACoder3.m
  2. 105
      Level_3/psycho.m

22
Level_3/AACoder3.m

@ -73,18 +73,26 @@ function AACSeq3 = AACoder3(fNameIn, fnameAACoded)
if i < 2 if i < 2
% TODO: what happens on the first two frames? % TODO: what happens on the first two frames?
SL = frameF(:, 1);
SR = frameF(:, 2);
continue;
else else
prev1FrameStart = (i - 1) * 1024 + 1; prev1FrameStart = (i - 1) * 1024 + 1;
prev1FrameStop = prev1FrameStart + 2047; prev1FrameStop = prev1FrameStart + 2047;
prev2FrameStart = (i - 2) * 1024 + 1; prev2FrameStart = (i - 2) * 1024 + 1;
prev2FrameStop = prev1FrameStart + 2047; prev2FrameStop = prev2FrameStart + 2047;
SMR = psycho(... SMRL = psycho(...
originalAudioData(currFrameStart:currFrameStop, :), ... originalAudioData(currFrameStart:currFrameStop, 1), ...
frameTypes{i+1}, ... frameTypes{i+1}, ...
originalAudioData(prev1FrameStart:prev1FrameStop, :), ... originalAudioData(prev1FrameStart:prev1FrameStop, 1), ...
originalAudioData(prev2FrameStart:prev2FrameStop, :)); originalAudioData(prev2FrameStart:prev2FrameStop, 1));
[SL, sfcL, GL] = AACquantizer(frameF, frameTypes{i+1}, SMR); SMRR = psycho(...
[SR, sfcR, GR] = AACquantizer(frameF, frameTypes{i+1}, SMR); originalAudioData(currFrameStart:currFrameStop, 2), ...
frameTypes{i+1}, ...
originalAudioData(prev1FrameStart:prev1FrameStop, 2), ...
originalAudioData(prev2FrameStart:prev2FrameStop, 2));
[SL, sfcL, GL] = AACquantizer(frameF, frameTypes{i+1}, SMRL);
[SR, sfcR, GR] = AACquantizer(frameF, frameTypes{i+1}, SMRR);
end end
[streamL, huffcodebookL] = encodeHuff(SL, huffLUT); [streamL, huffcodebookL] = encodeHuff(SL, huffLUT);

105
Level_3/psycho.m

@ -18,6 +18,107 @@ function SMR = psycho(frameT, frameType, frameTprev1, frameTprev2)
% - SMR is the signal to mask ratio array of dimensions 42X8 for % - SMR is the signal to mask ratio array of dimensions 42X8 for
% EIGHT_SHORT_SEQUENCE frames and 69X1 otherwise % EIGHT_SHORT_SEQUENCE frames and 69X1 otherwise
% Declares constant numbers of bands for long and short windows
end LONG_WINDOW_NUMBER_OF_BANDS = 69;
SHORT_WINDOW_NUMBER_OF_BANDS = 42;
% Declares persistent variable holding the TNS tables and initializes if empty
persistent TNSTables spreadingLong spreadingShort hannLong hannShort;
if isempty(TNSTables) || isempty(spreadingLong) || ...
isempty(spreadingShort) || isempty(hannLong) || isempty(hannShort)
TNSTables = load('TableB219.mat');
spreadingLong = zeros(LONG_WINDOW_NUMBER_OF_BANDS);
spreadingShort = zeros(SHORT_WINDOW_NUMBER_OF_BANDS);
% Calculates all possible spreading function results for long
% windows
tmpx = repmat(TNSTables.B219a(:, 5)', LONG_WINDOW_NUMBER_OF_BANDS, 1);
tmpx = tmpx - repmat(TNSTables.B219a(:, 5), 1, LONG_WINDOW_NUMBER_OF_BANDS);
indeces = logical(tril(ones(LONG_WINDOW_NUMBER_OF_BANDS)));
tmpx(indeces) = tmpx(indeces) .* 3;
indeces = ~indeces;
tmpx(indeces) = tmpx(indeces) .* 1.5;
tmpz = 8 * min((tmpx - 0.5) .^ 2 - 2 * (tmpx - 0.5), 0);
tmpy = 15.811389 + 7.5 * (tmpx + 0.474) - 17.5 * sqrt(1 + (tmpx + 0.474) .^ 2);
tmpSum = tmpz + tmpy;
spreadingLong(tmpy >= -100) = 10 .^ (tmpSum(tmpy >= -100) ./ 10);
% Calculates all possible spreading function results for short
% windows
tmpx = repmat(TNSTables.B219b(:, 5)', SHORT_WINDOW_NUMBER_OF_BANDS, 1);
tmpx = tmpx - repmat(TNSTables.B219b(:, 5), 1, SHORT_WINDOW_NUMBER_OF_BANDS);
indeces = logical(tril(ones(SHORT_WINDOW_NUMBER_OF_BANDS)));
tmpx(indeces) = tmpx(indeces) .* 3;
indeces = ~indeces;
tmpx(indeces) = tmpx(indeces) .* 1.5;
tmpz = 8 * min((tmpx - 0.5) .^ 2 - 2 * (tmpx - 0.5), 0);
tmpy = 15.811389 + 7.5 * (tmpx + 0.474) - 17.5 * sqrt(1 + (tmpx + 0.474) .^ 2);
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);
end
if ~strcmp(frameType, 'ESH')
% Applies window to the frames
windowedFrameT = frameT .* hannLong';
windowedFrameTprev1 = frameTprev1 .* hannLong';
windowedFrameTprev2 = frameTprev2 .* hannLong';
% Calculates the FFT of each frame
frameF = fft(windowedFrameT);
frameFMag = 2 * abs(frameF(1:1024));
frameFPhase = angle(frameF(1:1024));
frameFrameFprev1 = fft(windowedFrameTprev1);
frameFrameFprev1Mag = 2 * abs(frameFrameFprev1(1:1024));
frameFrameFprev1Phase = angle(frameFrameFprev1(1:1024));
frameFrameFprev2 = fft(windowedFrameTprev2);
frameFrameFprev2Mag = 2 * abs(frameFrameFprev2(1:1024));
frameFrameFprev2Phase = angle(frameFrameFprev2(1:1024));
% 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
bandEnergy(LONG_WINDOW_NUMBER_OF_BANDS) = 0;
bandPredictability(LONG_WINDOW_NUMBER_OF_BANDS) = 0;
for band = 1:LONG_WINDOW_NUMBER_OF_BANDS
bandEnergy(band) = sumsqr(frameFMag(TNSTables.B219a(band, 2) + 1: ...
TNSTables.B219a(band, 3) + 1));
bandPredictability(band) = sumsqr(frameFMag( ...
TNSTables.B219a(band, 2) + 1:TNSTables.B219a(band, 3) + 1) .* ...
framePredictability(TNSTables.B219a(band, 2) + 1: ...
TNSTables.B219a(band, 3) + 1));
end
% Convolves the partitioned energy and predictability with the
% spreading function
ecb = sum(bandEnergy .* spreadingLong', 2);
ct = sum(bandPredictability .* spreadingLong', 2);
% Renormalizes values
cb = ct ./ ecb;
en = ecb ./ sum(spreadingLong, 1);
% Calculates the tonality index
tb = -0.299 - 0.43 .* log(cb);
end
end

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