<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<META NAME="Generator" CONTENT="MS Exchange Server version 6.5.7036.0">
<TITLE>Audio transcoding/ASF mmsh Streaming WMP compatibility issue, current subversion</TITLE>
</HEAD>
<BODY>
<!-- Converted from text/rtf format -->
<P><FONT SIZE=2 FACE="Arial">I placed a file, shaunclip2.mp4 on my ftp. It was encoded as 128 kbps mp4v, 96K/channel mpga. The clip is a bit over 6 MB.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Using a current subversion VLC build, built by me on 1/20 at 10:00 EST. It includes asf.c 9792 2005-01-20 14:30:17Z</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">-->WMP10</FONT>
<BR><FONT SIZE=2 FACE="Arial">If I use:</FONT>
<BR><FONT SIZE=2 FACE="Arial">vlc shaunclip.mp4 :sout=#transcode{vcodec=DIV3,vb=128,scale=1.0,acodec=mp3,ab=96,channels=2}:duplicate{dst=std{access=mmsh,mux=ASFH,url=:1234}} </FONT></P>
<P><FONT SIZE=2 FACE="Arial">The resulting stream is OK for a WMP10 connection</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">If I instead use:</FONT>
<BR><FONT SIZE=2 FACE="Arial">vlc shaunclip.mp4 :sout=#transcode{vcodec=DIV3,vb=128,scale=1.0,acodec=mp3,ab=64,channels=2}:duplicate{dst=std{access=mmsh,mux=ASFH,url=:1234}} </FONT></P>
<P><FONT SIZE=2 FACE="Arial">(the only change is ab=64)</FONT>
<BR><FONT SIZE=2 FACE="Arial">WMP10 generates a CODEC message after the initial buffering:</FONT>
<BR><FONT SIZE=2 FACE="Arial">"An audio codec is needed to play this file. To determine if this codec is available to download from the Web, click Web Help."</FONT></P>
<P><FONT SIZE=2 FACE="Arial">It cannot find any CODEC, doesn't play the video.</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">A similar problem arises using a raw Directshow audio input. If I stream it using mp3 ab=96, the audio gets through to WMP10. If I try ab=64 I get the audio codec message.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Finally, if I start with a video that was originally encoded with 96K mp3, it does work OK doing a transcode to 64K/channel mp3. In other words:</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Vlc afile_with_96k_mp3.asf :sout=#transcode{vcodec=DIV3,vb=128,scale=1.0,acodec=mp3,ab=64,channels=2}:duplicate{dst=std{access=mmsh,mux=ASFH,url=:1234}} </FONT></P>
<P><FONT SIZE=2 FACE="Arial">The above will successfully output a stream with 64K mp3 to WMP10.</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">-->WMP9</FONT>
<BR><FONT SIZE=2 FACE="Arial">Also, there is currently a general WMP incompatibility. The above only holds for WMP10 -- in WMP9 the 96K mp3 will also not play properly, will generate a missing codec error.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">I cannot tell if the two things are directly related or if there are separate problems (audio transcoding and ASF muxing)</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Mark</FONT>
</P>
</BODY>
</HTML>