[mythtv-users] Hardware configuration and capabilities of MythTV

Raymond Wagner raymond at wagnerrp.com
Mon Feb 7 21:37:40 UTC 2011

On 2/7/2011 15:51, Reynolds, Brian wrote:
> I have been browsing the wiki since I sent my last message and see now
> that the ATI cards are not well supported in Linux.  I thought I read
> somewhere that there is a Windows version of Myth?

We have a frontend only build for Windows.  There is neither support for 
VfW or BDA, which are the primary capture APIs on Windows.

> Hmmm... that really blows if I wouldn't be able to watch/record the
> premium channels with either the HDHomeRun Prime or the Cable
> Box/firewire.  What's the point of the cablecard if I can't watch/record
> all the channels I paid for?

That is exactly what cablecard is for.  It allows access to any content 
you have subscribed to.

In a sane world, the tuner card would decide whether you had right to 
the content, and if so, decrypt it, and pass it onto the system 
unencumbered.  After all, you paid for the right to access that 
content.  That's how conditional access systems like CI cards with DVB 
systems work.  Sadly, they are moving to CI+, which is a scheme similar 
to CableCard.

CableCard is a DRM scheme, which means it must maintain control over the 
content at all times.  There are three levels: copy freely, copy once, 
and copy never.  Copy freely content is uncontrolled, meaning any 
content flagged as such is passed to the system unencumbered.  This is 
content we are allowed to access through MythTV.

Copy once content is not allowed to be duplicated, so in order to ensure 
this, the tuner card will only pass the content onto a Cable Labs 
certified device.  That means certified hardware, running a certified 
operating system, and certified media center software, and certified 
video hardware.  All together... that means Windows Media Center 7 and 
an HDMI/HDCP capable video card.  In this mode, content is captured, 
decrypted, encrypted, passed to the system, stored, read, passed back 
through the tuner card, authorized, decrypted, passed through a 
protected channel to the video card, decoded, encrypted, passed to the 
tv, decrypted, and displayed.  It reads like something out of 
Hitchhikers Guide.  Content cannot be removed from the system, must be 
authorized for playback at time of playback by the cable company 
(meaning they can lock you out of your recordings at any time) and can 
only be streamed to other compatible Cable Labs certified devices, 
meaning Media Center Extenders.

Copy never content is even more restrictive, and usually reserved for 
on-demand content, and other premium channels that offer on-demand 
services.  Content can be recorded and paused like with a normal DVR, 
but it has a enforced 90 minute rolling window.  After 90 minutes, the 
content is locked and deleted.

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