[mythtv-users] HDMI keep alive, maybe via sending silent audio?

[Simon Hobson]

John Veness <John.Veness.mythtv at pelago.org.uk> wrote:

> The soundbar (a Maxell MXSP-SB3000) was nice and cheap, gives good sound, and has a nice lot of inputs, but is otherwise not very configurable, so unfortunately it doesn't allow configuring to always take the audio from the HDMI ARC socket, independent of the HDMI switching capability. (It also doesn't accept discrete power off and power on commands, which makes programming a universal remote annoying).
> 
> Regardless of the "going to sleep" problem, I wish it could be made to always take audio from HDMI ARC, because something I haven't mentioned is that when it plays the audio directly from the HDMI input socket and passes the picture onto the TV via the HDMI ARC socket, the audio comes out slightly before the picture, presumably due to image processing delays on the TV. When the TV sends the audio out of its HDMI ARC socket, it seems to do so with no delay.

Yes, the TV will be compensating for it's processing delays and outputting the audio at the right time, the switcher cannot have any idea what delays the display has and cannot compensate for them.

> Luckily, with Myth at least (maybe not other sources) the audio can be set to be delayed, to counteract that.


> It may be that one solution would be to ignore the three other HDMI inputs on the soundbar and use a separate HDMI switcher, plugged into a separate HDMI socket on the TV, and use the TV's HDMI ARC output to the soundbar, which experimentation is showing that it would not sleep on silence.
> 
> But that does seem a waste ...

Yes indeed, you've bought an HDMI switch which "doesn't work" (for at least one definition of "work").
I'd be inclined to contact the manufacturer (or perhaps the vendor) first and complain that it a) "doesn't work" (as in turns off when it shouldn't) and b) "doesn't work" (as in "the sound isn't synced - don't tell them that you can adjust for it !). The latter makes the product "not fit for purpose" IMO.

Almost certainly both problems could be fixed by allowing use of ARC while switching HDMI inputs.