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How Media Player redirection and audio redirection works at the RDP Protocol level in Win2008R2 ? RRS feed

  • Question

  • Hi i am new to RDS and want to use its desktop and application sharing capabilities.

    Can anyone provide me with some document describing how RDP can be used to create its own RDP client.I mean any open specification document for RDP.

    Also can anyone provide me the details about how Windows Media Player redirection and similarly audio redirection works at the RDP protocol level.

    If i want to make my own RDP client then what shall i take care of to support audio and video redirection at the client side.



    Monday, October 8, 2012 2:43 PM

Answers

All replies

  • Hi Davinder,

    Thank you for your question.  A colleague will follow up with you soon to investigate this issue.

    Regards,

    Mark Miller | Escalation Engineer | Protocol Documentation Team

    Monday, October 8, 2012 6:09 PM
  • Hi Davinder,

    The base RDP protocol is [MS-RDPBCGR] “Remote Desktop Protocol: Basic Connectivity and Graphics Remoting Specification” available at http://msdn.microsoft.com/en-us/library/cc240445(prot.20).aspx.  You would also be interested in the Remote Desktop Services Protocols Overview [MS-RDSOD] at http://msdn.microsoft.com/en-us/library/gg454391(prot.20).aspx.. It lays the framework of the RDP protocol family.

    Regarding Windows Media Player, it uses [MS-RDPEV] “Remote Desktop Protocol: Video Redirection Virtual Channel Extension” for both audio and video playback.  See http://msdn.microsoft.com/en-us/library/dd342975(prot.20).aspx.  [MS-RDPEA] “Remote Desktop Protocol: Audio Output Virtual Channel Extension” is also available for audio redirection.  See http://msdn.microsoft.com/en-us/library/cc240933(prot.20).aspx.

    You may be interested in my blog at http://msdn.microsoft.com/en-us/library/cc240933(prot.20).aspx that describes how to capture, decrypt and parse Windows-to-Windows RDP traffic.  Using the technique described there will enable you to observe RDP traffic.  The latest Network Monitor Parsers, which includes the latest RDP parsers, are available at https://connect.microsoft.com/site216/Downloads.


    Bryan S. Burgin Senior Escalation Engineer Microsoft Protocol Open Specifications Team

    Monday, October 8, 2012 10:02 PM
    Moderator
  • Hi Bryan,

    Thanks for your quick reply.I will surely have a look at those provided links for more clarification.

    In the mean time can you clear my doubt regarding my perception that this Video redirection is only possible for Window Media Player via WMC through RDS at Win2008R2 or this video redirection feature can be made possible for some other media players like "VLC" and others, installed at Win2008R2 ?

     

    Regards,

    Davinder

    Tuesday, October 9, 2012 12:30 PM
  • Hi Davinder,

    From my casual use of VLC, it appears to use the same family of RDP protocols, including RDPEA and RDPEV for audio and video.  Your mention of WMC (Windows Media Center) needs a bit more explanation of the scenario you are referencing.  Are you probing Media Center Extenders or “Play To” technologies or something else.  “Play To” uses RTSP (Real Time Streaming Protocol).

    With the information I provided in my blog, you should be able to capture and analyze traffic yourself to discover the protocols involved in any-given situation.


    Bryan S. Burgin Senior Escalation Engineer Microsoft Protocol Open Specifications Team

    Tuesday, October 9, 2012 4:24 PM
    Moderator
  • Hi Bryan,

    My intend was that i want to know whether video redirection in Win2008R2 is possible only for Window Media Player or it can be made possible for other players like VLC ?

    I have Win2008R2 and when i play a video through Window Media Player then the content and audio at the client side is smooth and synchronized, i can clearly experience the video redirection feature of Win2008R2.

    But when i play the same video through VLC i am not having a better user experience at the client side.Both the video and audio content are not good and not in sync.Clearly the video redirection is not working in case for VLC.

    Are there any settings at the server side or by some means i can achieve the same user experience if i play any video apart from Windos Media Player ?

    If i make my own RDP client and i want to support video redirection for any type of player or device then what capabilities of the client i need to communicate to the server so that it initiates the video redirection for the client.?

    Regards,

    Davinder

    Wednesday, October 10, 2012 7:03 AM
  • I’m not sure why you have a poor experience with VLC.  From my casual experience with VLC, my impression was they were using RDPEA for audio whereas WMP is using RDPEV.  What codecs are used will also make a difference; I don’t recall what codecs they support.

    Let’s turn our discussion away from VLC as the focus of your question is really “If I make my own RDP client and I want to support video redirection for any type of player or device then what capabilities of the client I need to communicate to the server so that it initiates the video redirection for the client?”.  I believe my post of 8 October addressed that question.


    Bryan S. Burgin Senior Escalation Engineer Microsoft Protocol Open Specifications Team

    Monday, October 15, 2012 5:55 PM
    Moderator