默认不支持播放flv视频播放的。
修改方法:
1、打开/include/FCKeditor/editor/dialog/dede_media.htm 
if(playtype=="rm"
|| (playtype=="-" && (rurl.indexOf('.rm')>0 || rurl.indexOf('.rmvb')>0 || rurl.indexOf('.ram')>0)) )
{
revalue = "<embed src='"+ rurl +"' quality='hight' wmode='transparent' type='audio/x-pn-realaudio-plugin' autostart='true' controls='IMAGEWINDOW,ControlPanel,StatusBar' console='Clip1' width='"+ widthdd +"' height='"+ heightdd +"'></embed>\r\n";
}
下面添加以下内容:
//播放代码flv开始
else if(playtype=="flv" || (playtype=="-" && (rurl.indexOf('.flv')>0 || rurl.indexOf('.swf')>0)) )
{
revalue = "<object id='player' classid='clsid:D27CDB6E-AE6D-11cf-96B8-444553540000' name='player' width='"+ widthdd +"' height='"+ heightdd +"'> \r\n<param name='movie' value='/plus/player.swf'>\r\n<param name='allowfullscreen' value='true'>\r\n<param name='allowscriptaccess' value='always'>\r\n<param name='flashvars' value='file="+ rurl +"'>\r\n</object>";//播放代码flv开始结束
}
2、上传player.swf到/plus目录,搞定
使用时直接在Fckeditor中使用“插入多媒体”功能,输入flv结尾的视频地址和高宽度即可。