[mythtv] [mythtv-commits] mythtv/master commit: e090e9969 by Mark Kendall (mark-kendall)

[Martin Ellis]

Sorry it's late, but the reason for GPU vendors not including this
because of the minefield of support issues with the CEC protocol and
standard,

First thing, the CEC bus is a serial bus, all HDMI ports supporting
CEC must be interconnected, this is easy to achieve and comply with on
boards with embedded graphics and no expansion slot, but then how do
you connect an embeded graphics card CEC wire to an external graphics
CEC (i.e. via a USB - HDMI adapter) or via the PCI-Express slot.

Intel have already launched a board that exposes the CEC pin directly
on their board, and we are building a daughter card for that slot,
they are soon to release another, it is hoped other vendors will pick
up this HTPC Header and more widespread support will become available.

With Intel exposing the CEC wire, it proves they are aware of it and
had the opportunity to do something with it directly on the board, but
also shows their unwillingness to jump into that boat.

My view on why this is the case is fairly simple. If you advertise a
motherboard that is 100 euros as supporting CEC, and then the customer
purchasing that board connects it to an old TV that claims CEC support
but in fact its support is non standard, or even on modern TVs which
do support the standard v1.3 spec, but then extend it with custom
commands and then that customer finds they don't get the interactivity
they wanted, they have reason to return the board as faulty.

That's an expensive return for what in reality is no fault of the
Intel. It's far more sensible to expose the header, and then get a
company like us (Pulse-Eight) to take up that fight.

P.S Thanks for adding support, if any mythtv developers need or want
an adapter, please email support at pulse-eight.com and we will set you
up with a discount code.

Thanks

Martin

On Thu, Oct 27, 2011 at 4:07 PM, Dan Wilga
<mythtv-dev2 at dwilga-linux1.amherst.edu> wrote:
> On 10/26/11 10:47 PM, Tom Lichti wrote:
>> On Wed, Oct 26, 2011 at 10:23 PM, Robert McNamara
>> <robert.mcnamara at gmail.com <mailto:robert.mcnamara at gmail.com>> wrote:
>>
>>     On Wed, Oct 26, 2011 at 7:22 PM, Tom Lichti
>>     <tom at redpepperracing.com <mailto:tom at redpepperracing.com>> wrote:
>>
>>     >> Add libCEC support.
>>     >>
>>     >> This adds initial support for CEC HDMI devices which allow
>>     bidirectional
>>     >> communication and control between CEC capable devices.
>>     >>
>>     >
>>     > Am I correct in assuming you need the Pulse-Eight box to do this?
>>     > Tom
>>
>>     Yes.
>>
>>
>> Cool, but disappointing. Too bad nVidia hasn't gotten off their duff
>> and added it into their cards directly.
>>
> Based on what I've read, almost all video cards lack the hardware to
> interface between the nVidia chipset and the appropriate pin on the HDMI
> port. So if nVidia were to do this, it would only serve a very small
> portion of the users.
>
> Of course, nVidia could have encouraged vendors to include the hardware,
> but the horse has already left the gate on that one.
>
> --
> Dan Wilga                                                        "Ook."
>
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