Hi Jean-Marc<br><br>I'm looking at the 1.0.5 source, and I'm not seeing an _spx_lpc(). There's an _spx_autocorr(), which is in lpc.c and is called near the start of the encoder function in nb_celp.c.<br><br>The encoder seems to call the autocorr() function, then calls wld() to do something called Levinson-Durbin. Am I right in thinking that after the call to wld(), the st->lpc[] array contains the coefficients?
<br><br>Later on it computes "interpolated" LPCs -- are these what I want?<br><br>Thanks again for the help -- it's appreciated!<br><br><br><br><div><span class="gmail_quote">On 2/2/07, <b class="gmail_sendername">
Jean-Marc Valin</b> <<a href="mailto:jean-marc.valin@usherbrooke.ca">jean-marc.valin@usherbrooke.ca</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
> I'm interested in doing phoneme extraction, and one of the first steps in<br>> the algorithm I'm planning to use is to get the LPC coefficients for an<br>> input frame. Since Speex is CELP-based, the coefficients must be generated
<br>> in there somewhere. I've tried digging around in the source code, but I'm<br>> finding it slow going. Does anyone know if there's an easy way to get at<br>> the data?<br><br>The coefficients are generated by _spx_lpc(), but they're not stored
<br>directly in the bit-stream. However, if you look at the beginning of the<br>encoder function in nb_celp.c, you'll see it's not too much trouble to<br>get that code.<br><br> Jean-Marc<br></blockquote></div>
<br><br clear="all"><br>-- <br> Bernie Roehl<br> Software Consultant<br> Mail: <a href="mailto:broehl@gmail.com">broehl@gmail.com</a><br> Voice: (519) 577-8494<br>