The Analog Sunset

November 13, 2013 in Tech Talk by Sam Davisson

Waybackmachine3Back around the first of the year, 2012, the original version of this website crashed and I lost a number of articles that at least I had thought were pretty well done. Some, like this article which was originally written in July 2011, may be a bit dated as the analog sunset pretty much has set it did contain information that is still relevant. So, I’m here to re-post it and add it back into the legacy! 😉

What is the Analog Sunset?

The analog sunset is a part of the Advanced Access Content System or AACS license agreement. AACS is the encryption also know as Digital Rights Management System (DRM) adopted by content owners and device manufactures to protect content recorded on blu ray disk from copying or illegal distribution.

Content owners (ie. movie studio’s) want to limit the analog output from blu ray players, mainly the component outputs as they are the only analog outputs that are capable of producing an HD signal. For some reason, they believe that recording analog component video is easier than simply ripping a blu ray disk. As illogical as that argument is, it is a fact that we AV design engineers have to live with.

The AACS agreement implemented a couple of ways to accomplish this. The first is a hardware limitation mandated to be incorporated by the manufacture of players. This is what is known as the analog sunset. The second limitation may be used by content producers,
and comprise mechanisms known as the Image Constraint Token or ICT and the Digital Only Token or DOT.

Something to keep in mind, is the sun has already started setting. According to the final AACS adopter agreement in June of 2009:

Analog Sunset – 2010. With the exception of Existing Models, any Licensed Player manufactured after December 31, 2010 shall limit analog video outputs for Decrypted AACS Content to SD Interlace Modes only [composite video, S-video, 480i component video, and 576i video].

While this is quoted directly from the AACS adopter agreement, it may seem a little confusing to us mere mortal engineers where it tries to explain what the SD interlace modes are. 480i relates to standard NTSC video, 576i to PAL.

But, as you can see, the first part of the analog sunset has been in effect for about 6 months now. For the AV designer, that means that almost all of the pre-sunset blu ray players are out of the distribution cycle and the output limited ones are now being sold.

So, with the sun sitting halfway down in the western sky, when can we expect the it do dip below the horizon? Again, as defined by the final AACS adopter agreement of 2009:

Analog Sunset – 2013. No Licensed Player that passes Decrypted AACS Content to analog video outputs may be manufactured or sold by Adopter after December 31, 2013.

So we still have a couple of years before the analog hardware option is totally gone. But, keep in mind there are additional limitations that are already incorporated in the AACS agreement that are available to content providers now, the Digital Only Token (DOT) and the Image Constraint Token (ICT). While different both affect the blu ray player and the functionality of the analog outputs and both are defined as follows in the adopter agreement:

  • Digital Only Token shall mean the field, as described in the Specifications, used to trigger the limitation of output of Decrypted AACS Content to only-digital outputs.
  • Image Constraint Token shall mean the field, as described in the specification, used to trigger a Constrained Image as set forth in these Compliance Rules.
  • Constrained image is also defined in the agreement as follows:

    Constrained Image shall mean an image having the visual equivalent of no more than 520,000 pixels per frame (e.g., an image with resolution of 960 pixels by 540 pixels for a 16:9 aspect ratio).

    What I find interesting, using the term interesting loosely, is that a constrained image is of higher resolution and different aspect ratio than defined in the 2011 hardware analog sunset. But we will skip this anomaly, at least for now, and work with what DOT and ICT really mean.

    The Digital Only Token may only be set on blu ray disks that released within the first 6 weeks of the theatrical release or if disclosed on the packaging. This also affects cable or satellite TV only in respect to Video on Demand (VOD) services where content (movies) are available prior to the blu ray release.

    The Image Constraint Token can only be set on disks sold after December 31,2010. There seems to be a “gentleman’s agreement” between content producers and equipment manufactures that prohibits the use of this token until 2012 but since it is a “gentleman’s agreement” is there is no guarantee that disks with the token set will not soon show up. Use of the ICT must be disclosed on the packaging.
    What the Analog Sunset is not!

    The analog sunset only governs equipment licensed for AACS-encrypted content playback and has no authority over the playback of non-blu ray Disk media such as unencrypted media files, presentations, or CDs. Other means of content delivery utilizing a combination of software, hardware, and online services may or may not duplicate the licensing requirements or analog sunset features established by AACS for Blu-ray players. While not governed by AACS analog sunset requirements, other services that offer protected content for download or streaming, may require limitations on analog outputs. But this would depend on the policies of the particular service in question, and whatever agreements the service has with content owners such as the Motion Picture Association of America – MPAA.
    Keep in Mind …

    This affects all analog component outputs of a device capable of AACS encoded playback. That means that not only your blu ray disk player it also includes playing back through the analog output of your computer. Below is a simple table that I could have used to explain all this:

    Video Source Device Content Displayed Analog Output Status
    Blu Ray Disk Player Commercial Blu Ray Disk Standard definition only after 2010, disabled after 2013
    PC Commercial Blu Ray Disk Standard definition only after 2010, disabled after 2013
    PC Protected Content Depends on individual agreements between service
    provider and content owner
    PC Non-Protected Content Unaffected
    Satellite TV / Cable Box Subscribed channels May not be disabled in the US
    Satellite TV / Cable Box Video On Demand In the US, only to be disabled for new services offering
    first-run movies for 90 days or before availability on disk
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