New approach to H265 for the Portsdown

Discussion about this major DATV Project. See also https://wiki.batc.org.uk/The_Portsdown_Transmitter
G7JTT
Posts: 152
Joined: Fri Jun 10, 2016 5:05 pm

Re: New approach to H265 for the Portsdown

Post by G7JTT » Sun Dec 08, 2019 11:53 am

Hi Jacinto I think this hi-lights the issue that everyone has a slightly different setup and although this method works well for me, it's needs tweaking to each individual setup. Anyway hope to work you soon via the sat 👍

All best John

CU2ED
Posts: 6
Joined: Thu Jan 17, 2019 11:30 am

Re: New approach to H265 for the Portsdown

Post by CU2ED » Sun Dec 08, 2019 3:48 pm

Hi John,

Your setup is easy, quick and worked at first, as I said I had to go until 275Ks for stability, at 768x576 ou even 480p the image quality from the conversion of h.264 (from OBS) to h.265 it's OK, but I expected better with my C920, still very stable setup !!!
BTW, what is your delay on QO-100? I have about 3 or 4 secs max ...

Now with dvbsdr I have better quality with the same hardware and as I described on my last post, a delay of 4 secs, I wasn't successful with the lime FGA firmware, which can give me better quality, because when in use the delay is too much +- 9 secs, so I may have to tweak with some parameters?

For the moment I can't say the dvbsdr is very stable as your method, I'm doing more local tests, I do want an easy system and stable and the ability to work also with OBS ...
If it fails, I will prefer to use your setup instead of the dvbsdr ...
Again the use of jetson nano is cheaper than a new computer and it can interact with porstdown for h.265 encode without the use of PC, I tried to use
the picam V2 and the quality is acceptable, I can compare to my C920 using your setup, I just have to figure out how to add my call on screen, as we
have on porstdown mpeg2 ...

I still have a lot to learn but I think to have now everything to go on air and try some contacts, maybe we can have a QSO by sat :)

tks again

73

Jacinto
cu2ed

G7JTT
Posts: 152
Joined: Fri Jun 10, 2016 5:05 pm

Re: New approach to H265 for the Portsdown

Post by G7JTT » Sun Dec 08, 2019 7:06 pm

Yes 3 to 4 seconds is about the best I can achieve, I have tried dvbsdr with and without the FPGA but still like the simplicity of the Portsdown. There is nothing worse than just about to hit the TX and someone beats you to the spot hi. I must agree I was hoping for better quality with H265 from this setup, it may still be a wrong parameter somewhere yet. And totally agree still lots to learn but enjoying the journey so far and will continue to enjoy playing with DATV via QO100 for as long as we can.

All best John G7JTT

G7JTT
Posts: 152
Joined: Fri Jun 10, 2016 5:05 pm

Re: New approach to H265 for the Portsdown

Post by G7JTT » Wed Jan 08, 2020 7:12 pm

Looks like the link to the Nginx on the first post is dead here is another link but as yet I have not had a chance to try it
https://blog.100tb.com/how-to-set-up-an ... sing-nginx
All best John G7JTT

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