<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=gb2312">
<META NAME="Generator" CONTENT="MS Exchange Server version 6.0.6603.0">
<TITLE>[asterisk-dev] Suggestion on Packet Loss Concealment Algorithm</TITLE>
</HEAD>
<BODY>
<!-- Converted from text/rtf format -->
<P><FONT SIZE=2 FACE="Arial">Hi all,</FONT>
</P>
<P> <FONT SIZE=2 FACE="Arial">The current PLC algorithm uses only one pitch period, and therefore behaves bad during burst lost (Beeps in background),</FONT></P>
<P><FONT SIZE=2 FACE="Arial">I have prolonged the pitch period under burst loss situation and tested it using a small utility of ITU STL2005. As for the music files</FONT></P>
<P><FONT SIZE=2 FACE="Arial">(which were produced using VLC's file output module), the modified plc can handle 50% and 50ms long loss, although it might be that</FONT></P>
<P><FONT SIZE=2 FACE="Arial">the music wave doesn't vary very fast, i think the modification still improve the performance very much.</FONT>
</P>
<P> <FONT SIZE=2 FACE="Arial">The attachment is the rar of the modified files, very little change<FONT FACE="SimSun" SIZE=2 COLOR="#000000"> <<asteriskplc.rar>> </FONT>.<SPAN LANG="zh-cn"></SPAN></FONT><SPAN LANG="zh-cn"></SPAN>
</P>
<P><SPAN LANG="zh-cn"><FONT SIZE=2 FACE="Arial">Sincerely,</FONT></SPAN>
<BR><SPAN LANG="zh-cn"><FONT SIZE=2 FACE="Arial">Colin</FONT></SPAN>
</P>
</BODY>
</HTML>