Init AACquantizer for non ESH frames

Level_3/AACoder3.m

@@ -39,16 +39,6 @@ function AACSeq3 = AACoder3(fNameIn, fnameAACoded)
 
     % Declares constant window type
     WINDOW_TYPE = 'SIN';
-    
-    % Declares constant numbers of bands for long and short windows
-    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;
-    if isempty(TNSTables)
-        TNSTables = load('TableB219.mat');
-    end
 
     % Reads the audio file
     [originalAudioData, ~] = audioread(fNameIn);
@@ -74,8 +64,6 @@ function AACSeq3 = AACoder3(fNameIn, fnameAACoded)
     % Encodes audio file
     huffLUT = loadLUT();
     AACSeq3(length(frameTypes)) = struct;
-    TL(LONG_WINDOW_NUMBER_OF_BANDS) = 0;
-    TR(LONG_WINDOW_NUMBER_OF_BANDS) = 0;
     for i = 0:length(frameTypes) - 1
         currFrameStart = i * 1024 + 1;
         currFrameStop = currFrameStart + 2047;
@@ -103,19 +91,10 @@ function AACSeq3 = AACoder3(fNameIn, fnameAACoded)
                 frameTypes{i+1}, ...
                 originalAudioData(prev1FrameStart:prev1FrameStop, 2), ...
                 originalAudioData(prev2FrameStart:prev2FrameStop, 2));
+            [SL, sfcL, GL] = AACquantizer(frameF(:, 1), frameTypes{i+1}, SMRL);
+            [SR, sfcR, GR] = AACquantizer(frameF(:, 2), frameTypes{i+1}, SMRR);
             continue;
-            [SL, sfcL, GL] = AACquantizer(frameF, frameTypes{i+1}, SMRL);
-            [SR, sfcR, GR] = AACquantizer(frameF, frameTypes{i+1}, SMRR);
         end
-
-        for band = 1:LONG_WINDOW_NUMBER_OF_BANDS
-            TL(band) = sumsqr(frameF((TNSTables.B219a(band, 2) + 1: ...
-                TNSTables.B219a(band, 3) + 1), 1));
-            TR(band) = sumsqr(frameF((TNSTables.B219a(band, 2) + 1: ...
-                TNSTables.B219a(band, 3) + 1), 2));
-        end
-        TL = TL ./ SMRL;
-        TR = TR ./ SMRR;
         
         [streamL, huffcodebookL] = encodeHuff(SL, huffLUT);
         [streamR, huffcodebookR] = encodeHuff(SR, huffLUT);
@@ -136,6 +115,8 @@ function AACSeq3 = AACoder3(fNameIn, fnameAACoded)
         AACSeq3(i + 1).chr.stream = streamR;
         AACSeq3(i + 1).chl.codebook = huffcodebookL;
         AACSeq3(i + 1).chr.codebook = huffcodebookR;
+        
+        clearvars TL TR;
     end
 
     save(fnameAACoded,AACSeq3);

Level_3/AACquantizer.m

@@ -21,6 +21,62 @@ function [S, sfc, G] = AACquantizer(frameF, frameType, SMR)
 %        - G is the global gain stored in an array of dimensions 1X8 for
 %        EIGHT_SHORT_SEQUENCE frames and a single value otherwise
 
+    % Declares constant numbers of bands for long and short windows
+    LONG_WINDOW_NUMBER_OF_BANDS = 69;
+    SHORT_WINDOW_NUMBER_OF_BANDS = 42;
 
-end
+    % Declares persistent variable holding the TNS tables and initializes if empty
+    persistent TNSTables;
+    if isempty(TNSTables)
+        TNSTables = load('TableB219.mat');
+    end
+
+    if ~strcmp(frameType, 'ESH')
+        T(LONG_WINDOW_NUMBER_OF_BANDS, 1) = 0;
+        quantCoeff(LONG_WINDOW_NUMBER_OF_BANDS, 1) = 0;
+        sfc(LONG_WINDOW_NUMBER_OF_BANDS, 1) = 0;
+        for band = 1:LONG_WINDOW_NUMBER_OF_BANDS
+            frameWlow = TNSTables.B219a(band, 2) + 1;
+            frameWhigh = TNSTables.B219a(band, 3) + 1;
+            subFrameF = frameF(frameWlow:frameWhigh);
+
+            T(band) = sumsqr(subFrameF) ./ SMR(band);
+
+            % Calculates an initial quantization coefficient and attempts
+            % quantization
+            quantCoeff(band) = 16 * log2(max(frameF) ^ (3 / 4) / 8191) / 3;
+            S(frameWlow:frameWhigh, 1) = sign(subFrameF) .* floor(( ...
+                abs(subFrameF) .* 2 ^ (-quantCoeff(band) / 4)) ...
+                .^ (3 / 4) + 0.4054);
+
+            % Calculates current quantization error
+            quantErr = sumsqr(subFrameF - S(frameWlow:frameWhigh));
 
+            % Gradually increases the quantization coefficient
+            while quantErr < T(band) && (band > 1 || ...
+                    (quantErr(band) - quantErr(band - 1) + 1) <= 60)
+                quantCoeff(band) = quantCoeff(band) + 1;
+
+                S(frameWlow:frameWhigh) = sign(subFrameF) .* round(( ...
+                    abs(subFrameF) .* 2 ^ (-quantCoeff(band) / 4)) ...
+                    .^ (3 / 4) + 0.4054);
+
+                quantErr = sumsqr(subFrameF - S(frameWlow:frameWhigh));
+            end
+
+            if band == 1
+                sfc(band) = quantCoeff(band);
+            else
+                sfc(band) = quantCoeff(band) - quantCoeff(band - 1);
+            end
+        end
+        G = quantCoeff(1);
+    else
+        T(SHORT_WINDOW_NUMBER_OF_BANDS) = 0;
+        for band = 1:SHORT_WINDOW_NUMBER_OF_BANDS
+            T(band) = sumsqr(frameF((TNSTables.B219b(band, 2) + 1: ...
+                TNSTables.B219b(band, 3) + 1), 1));
+        end
+        T = T ./ SMR;
+    end
+end