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<TITLE>A question about "-lm" and "-output-ctm" when using lattice-tool</TITLE>
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<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Hi,</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> I generated a lattice file</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, htk.slf,</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> using a LM (lm1) in HTK. This LM has also been converted to SRI-LM format (lm2). </FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> Then, I tried using lattice-tool to decode the lattice.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> W</FONT><FONT FACE="Calibri">/o using</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">“</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">–</FONT><FONT FACE="Calibri">lm</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">, the following command generates the lm1.ctm with an WER identical to</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">the WER obtained in HTK</FONT></SPAN><SPAN LANG="en-us">.</SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> “</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">lattice-tool -read-htk -in-lattice</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">htk.slf</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">–</FONT><FONT FACE="Calibri">viterbi-decode</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> -output-ctm ></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">lm1</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">.ctm</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> However, when using “ -lm lm2”, the obtained lm2.ctm has a much worse W</FONT><FONT FACE="Calibri">ER compared to HTK</FONT><FONT FACE="Calibri">’</FONT><FONT FACE="Calibri">s result.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> “</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">lattice-tool -lm</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">lm2</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"> -no-expansion</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">-read-htk -in-lattice</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">htk.slf</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">–</FONT><FONT FACE="Calibri">viterbi-decode</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> -output-ctm ></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">lm2</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">.ctm</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">”</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> </FONT></SPAN><SPAN LANG="en-us"> </SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">For my understanding, since many parameters</FONT> <FONT FACE="Calibri">(e.g.,</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">LM weight and word</FONT> <FONT FACE="Calibri">penalty</FONT><FONT FACE="Calibri">)</FONT> <FONT FACE="Calibri">were</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">stored at the header of lattice file, we</FONT><FONT FACE="Calibri"> don</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">t need to specify them in the command line.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> I have studied manual of</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">lattice-tool for</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">a</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">while but cannot</FONT> <FONT FACE="Calibri">solve this problem</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">. Will you please help on this.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"></FONT> <FONT FACE="Calibri">T</FONT><FONT FACE="Calibri">hanks</FONT> <FONT FACE="Calibri">very much.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Lei</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<BR>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> </FONT></SPAN></P>
<BR>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri"> </FONT></SPAN></P>
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