Sample : http://code.msdn.microsoft.com/How-to-change-the-content-605b3df5
This code snippet shows how to change the content type of Windows Azure blob storage. In some cases, a lot of media files stored on blob are in different formats - mp4, image file, etc. Sometimes, all these files are set as one content type: application/octet-stream, which causes issues in media playback and progress bar. Many users would like to know how to set the appropriate Content-type for files stored on blob (like - video/mp4, video/ogg, video/webm)—not to do it manually for each file through blob interface. This script will help users easily batch change the content type of blob storage.
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