Portsdown 4 Repeater TX and Stream

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G3GJA
Posts: 337
Joined: Sun Nov 20, 2011 3:44 pm

Re: Portsdown 4 Repeater TX and Stream

Post by G3GJA » Tue Apr 12, 2022 12:36 pm

Hi Rob

Is your firmware version different to mine?

firmware.jpg
firmware.jpg (20.53 KiB) Viewed 6951 times

Mine also has an audio on/off control on the video tab:

audio.jpg
audio.jpg (20.54 KiB) Viewed 6951 times
I've set the sub-stream to 1280 x 720; does it needs to be manually forced and if so how did you do it?

Thanks

Clive

M0DTS
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Joined: Sun Feb 24, 2008 9:03 pm

Re: Portsdown 4 Repeater TX and Stream

Post by M0DTS » Tue Apr 12, 2022 1:56 pm

My boxes have older firmware.... could be something to do with it. V1.60.190919

The reason i use the old firmware is that the analog audio input is actually stereo which we needed at KM, not mono on future firmware versions.
I think i have a copy somewhere of an older firmware (which allows stereo audio) but not that 1.6 version.

The streaming settings are controlled from a python script, i found i could manually force 1280x720 on stream2 without it breaking, instead of the lesser quality options.

My python bits n bobs: https://github.com/m0dts/HDMI-Encoder-Tools


Rob

GI4DOH
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Joined: Mon Mar 26, 2018 8:44 pm

Re: Portsdown 4 Repeater TX and Stream

Post by GI4DOH » Tue Aug 09, 2022 9:31 pm

Going back to the original post in this thread, I too would like to stream and feed a Pluto - ultimately to produce a repeater but as Noel has suggested, start with streaming.
I understand from this thread and from https://wiki.batc.org.uk/Repeater_Controller that I need an HDMI encoder. To that end I have a Cam Link and one of the H264/H265 encoders that I have seen other people produce.
Unfortunately I hit a brick wall here. The Cam Link has a USB interface and the other encoder has an Ethernet connection - indeed this is the WiFi one from Ali Express although that doesn't help in any way. Ultimately I want the encoded stream to go to rtmp://rtmp.batc.org.uk/live/streamname-xxxx.
I have looked at the menus on my Portsdown 4 and while there are things to do with streaming I don't see anything that seems to relate to setting up such a path. I already use a Pluto on Thursday nights driven from my PC.
I see the Jetson getting a mention from time to time but no specific detail to let me build a picture in my mind of what I might specifically want one for.
There seems to be a missing link between encoding the HDMI input and sending it out to the streamer. I'm not stupid, just a bit thick at times. Can anyone point me in the right direction please?
Richard GI4DOH

GI4DOH
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Re: Portsdown 4 Repeater TX and Stream

Post by GI4DOH » Wed Aug 10, 2022 12:30 pm

I've made a bit of progress in that I can now stream to the BATC streamer with OBS - I'm trying to break this down into bite sized chunks.
That still leaves the question of can I do this from a Portsdown 4 as part of a repeater prototype or do I need an independant method to handle the streaming from a copy of the HDMI input?
I see references to HDMI splitters and the LKV373A. I know there is more than one way to skin a cat but I am looking for the simplest approach.
Any advice would be greatfully received.
Richard

GI4DOH
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Re: Portsdown 4 Repeater TX and Stream

Post by GI4DOH » Wed Aug 10, 2022 2:08 pm

Starting to see the wood as I fell the trees. My H.264/H.265 Encoder can go straight to the BATC Streamer with rtmp://rtmp.batc.org.uk/live/gi4doh-xxxx in the 'Video push' setting. No additional platform needed - now to investigate HDMI splitters.

G8GKQ
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Re: Portsdown 4 Repeater TX and Stream

Post by G8GKQ » Wed Aug 10, 2022 5:06 pm

Hi Richard

I'm also working on this problem. However, I am not using one of the Chinese H264/H265 encoder boxes as there seems to be no configuration control of them, and there are lots of slightly different models needing different settings.

For the input device, I am now using the CamLink 4K. Note that this simply captures the HDMI, it does not encode it.

There are 2 options for encoding:
  • A Raspberry Pi (4?) using ffmpeg will encode in H264 for transmission or streaming. I have a few tweaks to make, but this looks as though it will be good enough for 720p in 1MS FEC 2/3 with a LimeSDR. Alternatively, it should also stream OK at about 1Mb/sec to the BATC Streamer.
  • The Jetson Nano using GStreamer looks hopeful for H265 encoding for transmission. It should manage 1080p in 1MS FEC 2/3 with a LimeSDR.
The problem that I am having is that I can make these solutions work reliably with relatively noise-free input images, but if I try to digitise a noisy HDMI image, as would be output by an analogue FM receiver, the bitrate increases (doubles) even in CBR modes.

I have not found a single capture/processor solution that is able to transmit and stream at the same time, so an HDMI splitter and 2 capture devices may be required.

I am not using the Pluto as I am not confident in its reliability, although things have improved now that I have found out that it likes a 4.90v supply, and dislikes a 5.20v supply (the reverse of the LimeSDR's preferences!).

There are lots of cheaper (eBay) HDMI capture dongles and I plan to evaluate those once I have a working solution based on the CamLink 4K. The LKV373A was a reasonable solution for HDMI capture, but is no longer available in the quantities required for a recommended solution. I want a solution that is reproducible and likely to be available to purchase for a reasonable period of time!

I'll post more here once I have code good enough for experimental use.

Dave, G8GKQ

GI4DOH
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Joined: Mon Mar 26, 2018 8:44 pm

Re: Portsdown 4 Repeater TX and Stream

Post by GI4DOH » Wed Aug 10, 2022 6:34 pm

Hi Dave
Thanks for your reply. Fortunately I am only interested in DATV as we don't have an active analogue following over here.
The idea of having independant paths for streaming and for transmission seems logical enough. The only issue I noted with the cheap and chearful HDMI splitters on eBay is that both outputs would be the same resolution and I don't see a problem with that - I'll find out soon enough when mine arrives but I didn't see a lot of point in going for more expensive ones at the moment.
I got a Cam Link 4K on the strength of your recommendation and I see that as a simple way of getting HDMI into the Portsdown. I haven't tried connecting a Pluto to a Portsdown 4 yet but it's on my list of things to do.
My H.264/H.265 Encoder has video settings like H264/H265, Resolution, VBR/CBR, Framerate, Gop (whatever that is), Bitrate and a Quality field that is permanently set at 4. Audio settings have a few parameters too. Probably just a front end cover for FFmpeg but not as frightening to look at. I'll try streaming the output of my Ryde later and see how it gets on - if that works I don't need to look any further for a Streamer option - I know some day I will get a Jetson Nano but I'm not quite ready to start the steep learning curve on another branch of the big tree.
I'll check the voltage of the Buck Converter that I use for my QO-100 Pluto too although it has been very reliable on the Thursday night net. I was planning to use a Pluto with this project as I have one spare but the first step is to get a pair of Rydes streaming under a repeater controller.
I'm ready to try things out when you have somethings.
Richard

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