Good write up mfino.
The one exception to DVI being pure digital is on a CRT based display which is an analog output. DVI goes thru a Digital to Analog conversion for this type of output.
If I'm not mistaken the original HDTV format was 576p...and this is a PAL/SECAM format not NTSC or ATSC. The USA is standardized on NTSC for analog and ASTC for digital. This makes the current standard HDTV resolutions in the USA 720p and 1080i. the 540 number you saw could be a particular display's native resolution.
The encryption you discuss is present on almost all DVI and HDMI outputs...This is known as HDCP...
HDCP - What is it?
The iScan HD+ offers HDCP compliance and scaling of HD sources over DVI. What does that mean? High-Bandwidth Digital Content Protection (HDCP) is a standard, developed by Intel, designed to protect digital video and audio signals transmitted over
DVI connections between two HDCP-enabled devices.
A digital signal still retains perfect clarity, even after being copied an unlimited number of times. So, in order to protect copyright holders (movie studios, etc.) from having their programs copied and shared, the HDCP standard provides for the secure, encrypted transmission of digital signals. HDCP functions across
DVI connections between two HDCP capable devices. The source device (such as a DVD player or HDTV tuner) encrypts the digital signal using the HDCP standard, then sends that signal over the DVI or HDMI link to the receiving device (HDTV, etc.). The receiving device decodes the signal using HDCP and uses the signal as it is allowed.
If one of your devices is HDCP compliant, but the other is not, then you cannot connect them using DVI or HDMI - you will get an error. However, you can still use the analog signal from the source device (eg: component video signal, S-video signal). HDCP does not apply to analog signals.
The FCC approved HDCP as a "Digital Output Protection Technology" on August 4th, 2004. FCC regulations will require digital output protection technologies on all digital outputs from HDTV signal demodulators as of July 1st, 2005."
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