[mythtv-users] Cable box always on

[Brad DerManouelian]

Brian Wood wrote:
> Maybe, it's certainly an idea.
> 
> Some boxes can mute the audio, so the box could be on and not putting  
> out audio (I know, you should use the mute function of Myth, not the  
> STB, but I'm just pointing out possible problems).

Would you want to record if the audio was off, anyway? So the scenario 
is that the box is muted, you detect no audio and send a power command 
and the box turns off. During the next recording, it detects no audio 
and send the power command and turns the box back on - with audio.

So without the script, you end up with a bunch of recordings with no 
audio. With the script you record black for the first program and audio 
and video for the rest. You're still better off in the end.

Aside from the fact that the odds of a box being on and muted for some 
reason are so slim it's barely worth discussing.

> If the power function is a toggle, you are almost certainly going to  
> get turnoffs when you don't want them.
> 
> How long would you sample the audio? How would you tell the difference  
> between the box being off and an "artistic" silence or a news anchor  
> confronted by a malfunctioning prompter? You might need up to 10  
> seconds to be reasonably sure there was no audio, which would cause  
> long delays in switching.

If you are hooked up with digital audio from the STB to the myth box, 
you can tell if there's a link without having to actually analyze the 
audio coming through. I'm pretty sure all digital STB's have optical 
audio links. Whether or not your myth box is connected to it is another 
matter.

Barring a serial connection to the STB, I would say this is the 
second-best method.

-Brad