Video & audio halting

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
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g3yjr
Posts: 82
Joined: Sat May 23, 2020 1:37 pm

Video & audio halting

Post by g3yjr » Sat May 14, 2022 4:34 pm

I tuned to a 1000 kS signal from QO100. Clicking 'Receive' it locked and decoded, but the audio was halting from time to time and similarly, the video decode would collapse & recover.

Clicking 'Play to UDP Stream' gave solid play on VLC on a PC.

'Info' does complain the the voltage is low. Might a slightly low voltage cause this effect. My DVM says I'm feeding 5.13V to the RasPi4.

Graham

g0mjw
Posts: 2311
Joined: Sat Sep 20, 2014 9:15 am

Re: Video & audio halting

Post by g0mjw » Sun May 15, 2022 7:16 am

It could, but so could the format of the TS, not all transmissions are completely compliant, or it might be the codec being used, especially if high definition. The PI is not as powerful as current a desktop computers, it has limits. Help it with a proper power supply and ensure sufficient cooling so the CPU doesn't throttle.

Driving through the West Midlands last year avoiding an accident on the M6, this car was in front of me. It said G3YJR on the back. There was a problem with the local transport stream as it kept stopping and starting too, mostly to avoid collisions. Lack of bandwidth capacity on the link.

Mike

g3yjr
Posts: 82
Joined: Sat May 23, 2020 1:37 pm

Re: Video & audio halting

Post by g3yjr » Sun May 15, 2022 1:52 pm

I did find a 0V line off the Pi so I clipped it back on, retrieving 0.1 V.

Yes possibly the TS format. The beacon decoded fine on PD4.

OK about the YJR car. I've seen a number of callsigns on cars, but not that one. Perhaps it was a yorkshire jam roll provider's car? I like your traffic analogy.

Graham

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