Thanks for the great input on the https://discourse.vvvv.org/ thread.
Now it’s time to talk HDMI :)
HDMI’s lovely since it’s a nice compact rugged connector (always hated d-sub), and shifts lossless signal, but is prone to digital interference, causing signal drop outs or lost pixels.
We note that “HDMI is electrically compatible with the CEA-861 signals used by Digital Visual Interface (DVI)”
But cannot presume that we can interchangeably consider HDMI as a single link DVI signal.
Later editions of HDMI (e.g. 1.4 which introduces support for 120Hz/3D) use higher frequency of bandwidth in the cable than a standard DVI connector, but it is noted that HDMI equipment will still provide backwards compatibility with DVI.
HDMI connector B is electronically compatible with DVI dual-link, but as yet is not available in any products (and my guess is that we’re not likely to ever see this connector).
1. Mini DP -> HDMI
Any specific suggestions for active Mini-DP ->HDMI?
Tested at what resolutions?
2. HDMI cables
Length of cable
The specification for DVI notes maximum signal length as 5meters (despite evidence of up to 30meters or more working on occasion).
However, HDMI doesnt specify a maximum signal length.
A cable of about 5 meters (16 ft.) can be manufactured to Category 1 specifications easily and inexpensively by using 28 AWG (0.081 mm²) conductors.
With better quality construction and materials, including 24 AWG (0.205 mm²) conductors, a HDMI cable can reach lengths of up to 15 meters (49 ft.)
This seems to suggest that improments in cable quality could result in even longer lengths (e.g. 30meters), and due to the unidirectional video signal (i.e. unlike USB’s Tx/Rx), we can presume that any waveform effects / delay caused by the cable length is unimportant.
Affordable repeaters such as this one for £20 on Amazon:
promise to extend 1080p over 50meters
Furthermore, cables are popping up with inline extenders (£33 on Amazon for 20meters)
in 20 and 30meter lengths
Speed of cable
According to the HDMI spec, there are:
- Standard cables : 1080i/720p
- High speed cables : 1080p/4K/3D/Deep Color