Rename and fix getdelay.m to get_latency.m

git-svn-id: http://svn.parisson.org/svn/CNAQ/trunk@130 5fc3e0e6-29bc-4d03-b52b-c088cb822bde

diff --git a/tests/get_latency.m b/tests/get_latency.m
new file mode 100644 (file)
index 0000000..e5d893e
--- /dev/null
+++ b/tests/get_latency.m
@@ -0,0 +1,32 @@
+function [mfv,ecart] = get_latency(device, n)
+% this function allows measuring the latency of the playrecord process
+% where :
+% 'device' is the integer number of the audio card address from the ASIO
+% driver point of view (0 or 1, 2 etc...)
+% 'n' is the number of generation/acquisition operations
+% mfv: most found delay
+% ecart: standard deviation on delay
+
+    if nargin < 1, n = 10; end
+
+    %signal generation
+    f_min=20;
+    f_max=20000;
+    lt=5;  
+    t=0:1/44100:lt;
+    sig=0.9*chirp(t,f_min,lt,f_max,'logarithmic');
+    len_sig = length(sig);
+
+    %playrecord signal
+    for it = 1:n
+        pause(0.1);
+        inputbuffer = pa_wavplayrecord(sig',device,[44100],0,[1],[1],device,['asio']);
+        Co=xcorr(inputbuffer',sig');
+        [Y(it),I(it)] = max(Co);
+        delai(it)=I(it)-len_sig;
+
+    end
+
+    mfv=mode(delai);
+    ecart=std(delai);
+