Thanks for your quick answer.
I made some search by comparing the Viper’s quick tags embed and the oEMBED (described here)
It seems we have just to add the string
?version=3
just after the Youtube video ID ! I made a test with Google Chrome developer tool, it’s working.
But can you put me on the good way ?
The new Youtube player :
<object width="590" height="357"><param name="movie" value="https://www.youtube.com/v/nTDNLUzjkpg?version=3"><param name="allowFullScreen" value="true"><param name="allowscriptaccess" value="always"><embed src="https://www.youtube.com/v/nTDNLUzjkpg?version=3" type="application/x-shockwave-flash" width="590" height="357" allowscriptaccess="always" allowfullscreen="true"></object>
The old Youtube player (Viper’s Video Quick Tags) :
<object type="application/x-shockwave-flash" data="https://www.youtube.com/v/B7WcSd_Ju6o&color1=0x626262&color2=0x6AC8E6&rel=0&fs=1&showsearch=0&showinfo=1" width="590" height="360" id="vvq-6017-youtube-1" style="visibility: visible; "><param name="wmode" value="opaque"><param name="allowfullscreen" value="true"><param name="allowscriptaccess" value="always"></object>
<script type="text/javascript"> swfobject.embedSWF("https://www.youtube.com/v/B7WcSd_Ju6o&color1=0x626262&color2=0x6AC8E6&rel=0&fs=1&showsearch=0&showinfo=1", "vvq-6017-youtube-1", "590", "360", "10", vvqexpressinstall, vvqflashvars, vvqparams, vvqattributes);</script>