BATC Forum

I think I know the answer to this one ....

When on tx at 333ksps, H264 and FEC 7/8 and being decoded by MiniTuniouner the video suffers from lag and random freezes.

Using the same settings on my DATV express but with the audio bit rate set to zero to conserve bandwidth for video everything works 100% leading me to believe it is a Portsdown problem.

This issues only shows at low SR and I suspect it's related to not having turned the audio off on the Portsdown at low symbol rates.

Question - how do I disable the audio on low symbol rates and has anyone else had this 'problem' ?

73 Tim

Hi Tim

If you are really transmitting H264 on the Portsdown, then there is no audio (it doesn't add audio to H264).

If you are using the bouncing balls test card, then the occasional freezes are normal - a known problem that I have been unable to fix. However, the CAMH264 mode should be good and not freeze. If it does, the first suspect has to be your RPi power supply or cable. Put a scope on the 5v pin on the GPIO connector to check it.

The MPEG-2 modes (with or without audio) do not work well below 1000KS. That's where H264 comes into its own.

Dave

Hi Dave,

thanks for explanation - and yes it's only a problem on the test generator bounding balls - the Picam and H264 works as well as can be expected at 333ksps - noted about no audio on H264.

Just getting the final bugs out of my system and Gb3FT - looks like a few of the locals up this way are making the shift from Analog to digital.

73 Tim