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: 194
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: 11
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: 194
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: 194
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

M0YDH
Posts: 193
Joined: Sat Dec 31, 2016 5:59 pm

Re: New approach to H265 for the Portsdown

Post by M0YDH » Sat Mar 28, 2020 6:28 pm

Hi John,
My Lenovo Mini-PC is supposed to be the home of the video for streaming and OBS in this arrangement. It fails to display video from YouTube and crashes to the :( blue screen. VLC media player open video command is the same. I'm not too hopeful about it streaming a film with OBS on the local Portsdown LAN without crashing. Audio, regular programs and Minitouine are fine. It's a bit of an Achilles Heal!

Do you know if the Linux version of OBS would run on the Jetson Nano and would streaming to IPTSIN on Portsdown still be possible without a PC?
I've a perfectly good screen on my rack (as you know from mending it) which could use its HDMI input from the Nano. Another keyboard and mouse would be tolerable.

Now I've installed LAN cables to my workshop and streamed to my M0YDH channel on the BATC streamer, I can resume my Jetson Nano to Portsdown streaming experiments - if the PC plays ball.

73

David M0YDH

G7JTT
Posts: 194
Joined: Fri Jun 10, 2016 5:05 pm

Re: New approach to H265 for the Portsdown

Post by G7JTT » Sat Mar 28, 2020 7:46 pm

Hi David I've not tried OBS on the Jetson, but if and when I get locked down like most of the population I'll give it a try. Still very busy at work at the moment and I seem to have less and less time to play 😪 my front lawn is the only one not cut and my car still needs a wash hi.

All the best and stay safe John

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

Re: New approach to H265 for the Portsdown

Post by CU2ED » Mon Mar 30, 2020 12:30 pm

Hi John and David,

>> Do you know if the Linux version of OBS would run on the Jetson Nano and would streaming to IPTSIN on Portsdown still be possible without a PC?

I tried OBS in Jetson board and it works (H264), you must apply a patch to an old version, but it's limited, you can read more, the reason, in this links:

https://obsproject.com/forum/threads/bu ... h64.85875/
https://imgur.com/a/XqsTDRf

73

Jacinto
cu2ed

M0YDH
Posts: 193
Joined: Sat Dec 31, 2016 5:59 pm

Re: New approach to H265 for the Portsdown

Post by M0YDH » Wed Apr 01, 2020 6:44 pm

Hello both
Yes I found independently that Jetson Nano and OBS Studio are incompatible.
However I have updated a Dell Latitude D630 laptop from Linux Mint 17.2 up to 19.3 Tricia XFCE via an overwrite with the Live DVD. This does permit OBS and FFMPEG and it was at zero cost to me :D . Now I have to follow the OBS for windows settings in CQ-TV 265 and any from this article. There are two experiments to try
1) CQ-TV 265 style - make some Bash scripts that do what the Windows batch file did for H264 transport stream straight to Portsdown.
2) carry out the OBS export to the Jetson Nano per this article in order to make H265 in a 3 computer chain.

Hopefully the 2008 vintage laptop will perform adequately

73

David M0YDH

KA5BBC
Posts: 63
Joined: Thu Jun 28, 2018 6:59 pm

Re: New approach to H265 for the Portsdown

Post by KA5BBC » Thu Jun 11, 2020 2:46 pm

If I were to want to change from H264/265 encoding to GSE encoding what would I change in the encoder parameters part of the script as listed on the wiki?

I am experimenting to see if the Portsdown, with or without Jetson Nano, can be successfully used with a DVB-S2X/DVB-GSE system.
Andy, KA5BBC/MM0BQV

G8GKQ
Site Admin
Posts: 1601
Joined: Sun Mar 22, 2009 1:21 pm

Re: New approach to H265 for the Portsdown

Post by G8GKQ » Thu Jun 11, 2020 5:25 pm

Hi Andy

The best answer I can think of to your question is that if I was trying to generate DVB-S2 I would start looking at the modifications required in the C and C++ code that generates the TS in the Jetson Nano. It can't be done simply by changing the encoder parameters.

However, that would not be the approach that I would take - I would start by getting one of the open source GNU Radio implementations of the protocol working first on a PC.

Dave

Post Reply

Return to “The Portsdown Digital ATV System”