how to capture and upload videos to the server.

Question

Hi, I'm developing windows phone 8 app. I need to record 12 sec video and upload to the server. Im able to record the video but not able to upload to the server, getting null response or out of memory exception. I'm using restsharp toolkit to upload the files to the server. Also I dont know how to get the thumbnail image for recorded video. Can anyone help? Please help if there is any solution. Thanks.