[mythtv-users] Channel change script, PVR-150, and tinny audio

Paul Fine pfine at comcast.net
Tue Dec 12 15:16:29 UTC 2006

I have set up my MythTV so that the composite input is from a second 
video source (the first source is analog cable), which I call VCR.  This 
video source has 1 channel (chennel 0).  I can now set up a manual 
recording on channel 0, start my VCR, and capture my Rocky and 
Bullwinkle collection onto my MythTV.

I used


to set up this configuration.

Unfortunately, I have the tinny audio problem.  I found I could correct 
the PVR-150 audio capture problem by issuing the v4l2-ctl command

[root at oscar ~]# v4l2-ctl -d /dev/video1 --set-ctrl=audio_emphasis=2

This worked both times I tried it.

I am looking for a way to automatically issue the v4l2-ctl command when 
I start recording on my "VCR" input.  I was thinking that perhaps the 
channel changing script will do this for me.  In my configuration for 
this video source, the channel change script is set to "/bin/true".  If 
I changed the value to point at a script that ran the v4l2-ctl command, 
and then returned true, would that do what I wanted it to do?

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