<!-- begin embedded WindowsMedia file... -->
<table border='0' cellpadding='0' align="left">
<tr><td>
<OBJECT id='mediaPlayer' width="320" height="285"
classid='CLSID:22d6f312-b0f6-11d0-94ab-0080c74c7e95'
codebase='http://activex.microsoft.com/activex/controls/mplayer/en/nsmp2inf.cab#Version=5,1,52,701'
standby='Loading Microsoft Windows Media Player components...' type='application/x-oleobject'>
<param name='fileName' value="http://www.tudominio.com/ruta/archivo.avi">
<param name='animationatStart' value='true'>
<param name='transparentatStart' value='true'>
<param name='autoStart' value="true">
<param name='showControls' value="true">
<param name='loop' value="true">
<EMBED type='application/x-mplayer2'
pluginspage='http://microsoft.com/windows/mediaplayer/en/download/'
id='mediaPlayer' name='mediaPlayer' displaysize='4' autosize='-1'
bgcolor='darkblue' showcontrols="true" showtracker='-1'
showdisplay='0' showstatusbar='-1' videoborder3d='-1' width="320" height="285"
src="http://www.tudominio.com/ruta/archivo.avi" autostart="true" designtimesp='5311' loop="true">
</EMBED>
</OBJECT>
</td></tr>
<!-- ...end embedded WindowsMedia file -->
<!-- begin link to launch external media player... -->
<tr><td align='center'>
<a href="http://www.tudominio.com/ruta/archivo.avi" style='font-size: 85%;' target='_blank'>Launch in external player</a>
<!-- ...end link to launch external media player... -->
</td></tr>
</table>

http://www.todoexpertos.com/categorias/tecnologia-e-internet/desarrollo-de-sitios-web/macromedia-dreamweaver/respuestas/653514/insertar-avi-o-mov-en-un-swf

Se recomienda energicamente usar Flash porque el plugin de Flash esta mucho más distribuido.

Insertar .avi en documento html con WindowsMedia

HTML