Abstract: A system for monitoring the quality of DRM-protected multimedia data streams, the system comprising at least one computer having a network connection to receive at least one said DRM-protected multimedia data stream, program memory, working memory, and a processor coupled to said program memory, working memory, and wherein said program memory stores processor control code for a media player for said multimedia data stream and code to control said processor to: play said DRM-protected multimedia data stream to provide at least a decrypted video data output stream for display on a monitor; capture still image data from a succession of still images from said video data output stream; process said still image data to detect greater than a threshold difference between at least two of said still images; and output fault data identifying a potential video quality fault responsive to absence of detection of said greater than a threshold difference.

Abstract: A system for monitoring the quality of DRM-protected multimedia data streams, the system comprising at least one computer having a network connection to receive at least one said DRM-protected multimedia data stream, program memory, working memory, and a processor coupled to said program memory, working memory, and wherein said program memory stores processor control code for a media player for said multimedia data stream and code to control said processor to: play said DRM-protected multimedia data stream to provide at least a decrypted video data output stream for display on a monitor; capture still image data from a succession of still images from said video data output stream; process said still image data to detect greater than a threshold difference between at least two of said still images; and output fault data identifying a potential video quality fault responsive to absence of detection of said greater than a threshold difference.