Changes between Version 3 and Version 4 of DSP/Interpolation

Timestamp:

Aug 4, 2015, 7:00:27 AM (9 years ago)

Author:

dlambros

Comment:

—

DSP/Interpolation

@@ -53 +53 @@
 Go back to the original .WAV File and listen to the audio. Then listen to the output file and notice the difference and effects of upsampling an audio sample.
 == Interpolation of a Sinusoidal Wave with Octave ==
+To start off make a simple sine wave
+{{{
+signal = sin(2*pi*3.*[0:.01:1]);
+plot(signal);
+}}}
+[[Image(sine.png, 500px)]]
 
+Then continue by entering
+{{{
+signal_zeropadded = [signal;zeros(3,length(signal))];
+signal_zeropadded = signal_zeropadded(:);
+pkg load signal
+b = fir1(10,.12);
+signal_interpolated=filter(b,1,signal_zeropadded);
+plot(signal_interpolated)
+}}}
+[[Image(sine_interpolated.png, 500px)]]
+== Interpolation of a .WAV File with Octave ==
+{{{
+[signal, fs] = auload("island(1).wav");
+signal_zeropadded = [signal;zeros(3,length(fs))];
+signal_zeropadded = signal_zeropadded(:);
+pkg load signal
+b = fir1(10,.12);
+signal_interpolated = filter(b,1,signal_zeropadded);
+plot(signal_interpolated)
+}}}
 
+The plot should look like
+
+[[Image(sig_interpolated.png, 500px)]]
+
+Then to save the interpolated signal as a .WAV file with the following command
+{{{
+wavwrite(signal_interpolated, 'islands.wav');
+}}}
 == Troubleshooting ==
 
@@ -81 +115 @@
 and should see the following
 
-[[Image(pkglist.png, 650px)]]
+[[Image(pkglist.png, 500px)]]
 
 
@@ -93 +127 @@
 If you receive the following error
 
-[[Image(fir1_err.png, 650px)]]
+[[Image(fir1_err.png, 500px)]]
 
 you will need to install the signal package.
@@ -104 +138 @@
 
 If you receive the following error:
-[[Image(signal_err.png, 650px)]]
+
+[[Image(signal_err.png, 500px)]]
+
 you will need to install the control package with the command
 {{{