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Does anybody know if there is an effective way to catch the streamed output of Silverlight and saving it to the Hard disk (in any format) without using screen capturing tools?

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Might be a duplicate of "Capture specially encoded videos?" at – Arjan Oct 29 '09 at 12:15
Not exactly, the problem there is apparently with the codecs. I don't have to manipulate AVI files, but capture streaming content and save it. – Overflow Oct 29 '09 at 14:21
up vote 4 down vote accepted

If you're familiar with .NET/IL Sourcecode:

  1. Locate the Silverlight .xap file and save it to your computer.
  2. Change the extension from .xap to .zip and open it.
  3. You'll find one or more Dlls. Take them, starting with the one looking like it's just for that Silverlight application. (You can probably skip thirdparty ones.)
  4. Disassemble that Dll with IL DASM or other IL disassembler tools.
  5. Search for the source Uri of the video stream. Theoretically, it could be anywhere in the dump, look out in the main page's source. It will just look like a link to a media file, maybe .asx.
  6. You can not download it as a simple file. Remember it's a stream! Use a program like VLC which is capable of saving and encoding a stream. There you go.


  1. Start your favorite Network Sniffer (like Microsoft Network Monitor).
  2. Look out for the HTTP request which is followed by a massive flood of responses. Thats the Uri for your stream. Continue with 6. in the first section.
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Where is the moov atom? I couldn't find it from the stream. – Joni May 2 '12 at 7:39

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