Hi,
I have to setup VOIP service DN with options service type treatment and contact option to stream manager, they i will be able to use the playannouncement treatment. Then just in the prompts in play announcement i should put in the text the path to your video file. Yesss it works, and i understand now, HOW it works.
GREAT! 
Thank you!
ps: and delete the TServer option request-uri from the VoIP Service DN. When this option points to the video_sample file, i cant play an another announcement to the caller from the routing strategy…