Making the most out of HDMI

[thatgui]

As far as I know, we are pretty much stuck with an HDMI, so lets make the best out of it:

The HDMI standard contains a little more than just the specifications to transfer audio and video data. My intention while creating this thread was to gather additional features that come with HDMI 1.4a, discuss usecases, gather information wether they need additional hardware and wether there is already open source code to utilize it.

The current list is based on what HDMI 1.4a offers as its what the OMAP5 support, other SoC (that are still candidates) may offer a higher version ( V.20):

• CEC - Consumer eletronic control
  - Control various functions of a connected device
  - Don't know if additional hardware is required
  - Don't know the effort on software side, XBMC can support it per plugin, raspberry pi has this functionality, so someone could lard there if the OS needs some adjustments to support it.
  - Usecase I see: You are somewhere (like a hotel romm) were you want to watch a movie on a bigger screen and instead of going back and forth, to choose the movie, and to play/pause etc. just fire up a software that supports it (like XBMC) and use the TV remote
  I personally use a USB - CEC adapter from pulseeight, to control my XBMC box > I just works great and the WAF - factor is extraordinary
• HEC  - HDMI Ethernet Channel
  - Share an ethernet connection with a connected device, sounds like a nice addition, but can't think of a "valid" usecase
  - http://www.hdmi.org/manufacturer/hdmi_1_4/hec.aspx
  
• ARC - Audio return channel
  - As far as I did understand it, it can be utilized to be more "flexible" in distributing / redirecting audio data in a more complex device setup (like an extra amplifier)
  - http://www.hdmi.org/manufacturer/hdmi_1_4/arc.aspx
• ACS - Automotive connection System
  - Don't know anything, may be usefull for people that want to use the Pyra as a car entertainment system
  - http://www.hdmi.org/manufacturer/hdmi_1_4/automotive_connection.aspx
   

 

[levi]

Interesting, I only knew about using CEC for simulating the old SCART status pin (for switching inputs).


HEC could be an interesting way to do hard networking, though I can't immediately find a box that takes HDMI and splits out the ethernet on sale, and I don't know how hard it would be to wire it in to the board.


ARC could be useful if the Pyra has as good audio hardware as the Pandora, so you could use it as a headphone amp while watching TV


That ACS page just talks about a new chunky connector for use in car. Pyra's going for microHDMI I assume.

 

[mcobit]

I guess that all those features are part of the soc and only need to be exposed in software?


Would be great to have them though to use the Pandora as a mobile mediacenter.

 

[thatgui]

I guess that all those features are part of the soc and only need to be exposed in software?

Don't know for sure, my HTPC box (some Shuttle barebone) has HDMI out, but I need the USB - CEC adapter (which is connected "inbetween" the HTPC and the TVs HDMI connection) to create the necessary signals - but then again, that may be due to the HTPC not supporting a HDMI 1.2a.

 

[Puppetmaster]

Perhaps could HEC be useful in a Pyra Dock to provide an Ethernet connection to the device.

 

[thatgui]

Perhaps could HEC be useful in a Pyra Dock to provide an Ethernet connection to the device.

This would mean that a Ethernet - HDMI "converter" needs to be made that at least partially reimplements the HDMI protocoll, maybe to much hassle for a dock (which will certainly be the niche in a niche).

 

[Trezker]

I am mosly interested in CEC.

May certainly be useful in many situations.