- Source: Janus (DRM)
Janus was the codename of a version of Windows Media DRM primarily for portable devices, whose marketing name was Windows Media DRM for Portable Devices (or in short form WMDRM-PD). It was introduced by Microsoft in 2004 for use on portable media devices which store and access content offline. Napster To Go was the first online music store to require the Janus technology. Supporting Janus often implies that the device also makes use of Media Transfer Protocol (MTP).
Janus initially required supporting devices to not support non-Microsoft audio formats such as Ogg Vorbis, but this requirement was later removed.
Characteristics
To support Janus, devices must support:
Secure time
License storage for content items
Meters
All of these are supported by way of challenge–response authentication commands.
Stores that required Janus on portable devices
Devices that used Janus
Most BlackBerry OS devices
Audiovox SMT 5600 smartphone
Toshiba Gigabeat S
Cowon iAudio X5 (as of firmware 2.11b1)
Cowon iAudio U3
Creative Zen portable players (except Stone and Stone Plus)
Dell DJ 20GB (Gen 2)
Dell DJ 30GB
Dell Pocket DJ
iriver Clix
iriver H10 series (with MTP firmware only)
iriver H320 (US version only; after upgrading to EU/KR/JP firmware, DRM capabilities are lost)
iriver H340 (US version only; after upgrading to EU/KR/JP firmware, DRM capabilities are lost)
iriver PMC-120 (Portable Media Center)
Samsung YH-925 (not Australian or European version as onboard radio is lost if firmware is upgraded)
Samsung YH-999 Portable Media Center
Samsung YP-T7Z
Samsung YP-U2JXB/W
Palm OS devices running Pocket Tunes Deluxe software
Archos 404
Archos 504
Archos 604
Archos 604 Wi-Fi
Archos AV700
Archos AV500
Archos Gmini402
Archos Gmini500
All Windows Mobile devices running Windows Media Player 10
Nokia N72
Nokia N91
TrekStor vibez
Microsoft Zune (though incompatible with the PlaysForSure stores)
Sandisk Sansa
Popcorn Hour C-200
All Roku DVP devices
References
External links
U.S. patent 7,010,808
Nokia N72