BATC Forum

GB3FT is back on the air and working quite well, however there is a minor issue with the audio channel.
It uses the BATC repeater controller running on a RPI 4 but from time to time the audio form the H265 encoder box drops out resulting in tota loss of audio.
I note there is a config setting for keep alive audio noise, but it seems to do nothing and no noise can be heard in the audio channel - maybe I've got a setting wrong in the config file ?
I'm also wondering if instead of noise the repeater could insert a .wav file of licence free music ? This would be a better indication of normal operation when the repeater is not in use.

73 Tim

Hi Tim

What method of audio switching are you using? i2C switching of analog audio, or hdmi?

If hdmi, do you have any non-Raspberry Pi sources feeding the hdmi switch?

73

Dave

Hi Dave
thanks for replying promptly.
FC is quite simple - it relies on the Portta HDMI switch to handle video and audio (carried in hdmi), all four ports of the HDMI switch are fed from RPI's as follows
1. BATC controller
2. RYDE rx
3. RYDE as composite to HDMI converter
4. RPI 3, SRT stream rx to hdmi

The portta switch is driven by IR commands and seems ok, also seems to switch audio ok, but the controller as far as I can tell does not generate noise to keep the H265 AF encoder path happy.

No I2C audio switching at this time.
In FC the output of Portta switch goes to Chinese H265 box.

The problem is more freqent with the off air stream rx which has HDMI directly to the H265 encoder, ie no portta switch in the way.

The off air stream rx needs to be started / reset in a particular sequence, ryde up and running first generating AF then reset the H265 box so it correctly detects the audio signal (and video).
If the off air ryde rx is not generating af then the h265 box tends to get screwed up - thus if FC is quiet on the AF channel it messes with the off air audio signal as well.

Thus I suspect the root cause is a quiet audio channel - hence investigating noise or music to keep it alive.

Hope this makes things a little clearer.

73 Tim