prototype undersampling code

git-svn-id: https://svn.code.sf.net/p/freetel/code@929 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/codec2-dev/octave/undersample.m b/codec2-dev/octave/undersample.m
new file mode 100644 (file)
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+++ b/codec2-dev/octave/undersample.m
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+% undersample.m
+% David Rowe 5 Nov 2012
+% Testing algorithms for plotting undersampled data for fdmdv2 waveform displays
+
+fs=fopen("../raw/hts1a.raw","rb");
+s = fread(fs,Inf,"short");
+
+Fs1=8000;
+Fs2=200;
+
+M=Fs1/Fs2;
+
+samples=length(s)/M;
+s1=zeros(1,2*samples);
+for b=1:samples
+    st = (b-1)*M + 1;
+    en = b*M;
+    s1(2*b-1) = max(s(st:en));
+    s1(2*b) = min(s(st:en));
+end
+
+subplot(211)
+plot(s)
+subplot(212)
+plot(s1);
+