diff yetilab/stream/framer.yeti @ 285:be39f21456a1

More on overlap-add for frames

--- a/yetilab/stream/framer.yeti	Wed May 29 22:59:23 2013 +0100
+++ b/yetilab/stream/framer.yeti	Thu May 30 17:34:35 2013 +0100
@@ -94,11 +94,25 @@
         close = \(),
     });
 
+overlapAdd channels framesize hop frames =
+   (ola fr acc =
+        if empty? fr then
+           [acc]
+        else
+            frameSized = mat.resizedTo
+               { columns = framesize, rows = channels };
+            extended = frameSized
+               (mat.columnSlice acc hop (mat.width acc));
+            added = mat.sum (frameSized (head fr)) extended;
+           (mat.columnSlice acc 0 hop) :: ola (tail fr) added;
+        fi;
+    mat.concat (Horizontal ()) (ola frames (mat.zeroSizeMatrix ())));
+
 streamOverlapping rate framesize hop frames =
    (var remaining = frames;
     var buffered = mat.zeroSizeMatrix ();
     var position = 0;
-    w = win.hann framesize;
+    w = win.windowFunction (Hann ()) [ Symmetric true ] framesize;
     channels = mat.height (head frames); // so we don't need to keep a head ptr
     filt.delayedBy (- (framesize - hop))
         {
@@ -125,7 +139,9 @@
                         remaining := tail remaining;
                         framesFor (samples - hop) (acc ++ [this])
                     fi;
-                source = mat.concat (Horizontal ()) (framesFor count [buffered]);
+                source = overlapAdd channels framesize hop
+                   (framesFor count [buffered]);
+//                println "source = \(source)";
                 toReturn = mat.columnSlice source 0 count;
                 buffered := mat.columnSlice source count (mat.width source);
                 toReturn),
@@ -169,6 +185,8 @@
     frequencyDomainFramesOfFile parameters filename = 
         frequencyDomainFrames parameters (af.open filename),
 
+    overlapAdd,
+
     streamed,
 }