Portsdown 4 Camlink 4K HDMI Dongle Support

[G8GKQ]

I have just released a new version of the Portsdown 4 (202209070) which provides limited support for the Elgato Camlink 4K HDMI capture dongle. Simply connect the dongle by USB3 and select the HDMI input. The new functionality that has been tested is:

• LimeSDR Transmit at 1MS FEC 2/3 H264 at 720p definition. Audio either from the HDMI source or an Easycap (to allow for stereo analogue audio input).
• LimeSDR Transmit at 333ks FEC 2/3 H264 at 16:9 (800x448 in this case) definition. Audio either from the HDMI source or an Easycap (to allow for stereo analogue audio input).
• Streaming of HDMI video ONLY to the BATC Streamer at 720p. Audio not yet working.
• Display of incoming HDMI video on the touchscreen for set-up purposes (not during TX). Select M2, HDMI monitor.

The dongle will not work with a Pluto. Neither will other models of HDMI dongle work at all. Don't even ask!

The dongle needs USB3 connectivity, so this enhancement cannot be provided to the Portsdown 2020.

Please let me know here if I have broken anything else in the changes required to make this dongle work.

Note that this enhancement means that the Portsdown 4 is now a very good basis for an HDMI-input repeater transmitter.

Dave, G8GKQ

[G1LPS Terry]

Nice to have this addition Dave
I was watching your github and saw this might be coming so grabbed a bargain price 4K dongle when one came up.
Working here as per your post.

Terry G1LPS

[VK3IE]

Dave
Sweet bit of Kit to add to the mix. Excellent
Thank You Dave

Robert
vk3ie

[G3GJA]

Dave

I have a couple of queries:

Is this capability built into the Portsdown Repeater build yet?

Is there any possibility of a IPTS output from the Portsdown using the dongle as an input?

Could the Pluto be used with further development? The Group has already invested in a Pluto and the Lime Mini if and when it becomes available is now very expensive.

The answers will steer which way GB3EY's analogue signal based logic is changed to an all digital solution. A breadboarded Portsdown Repeater/Pluto (Ethernet connection)/Chinese H265 encoder/HDMI switch system has been assembled and tested. Like others that have tried the H265 coder approach, I've found the results to be unreliable.

Thanks

Clive

[G8GKQ]

Hi Clive

Yes, this is the basis for the latest Portsdown 4 Repeater Build. The repeater card build instructions are here https://wiki.batc.org.uk/Portsdown_4_HD ... Card_Setup.

An IPTS output might be possible - please could you give me more details about how it would be used and the parameters required?

I'm struggling to get the HDMI dongle to work with the Pluto at the moment. Same issue as the stream output - video is OK, but I can't make the audio work.

Dave, G8GKQ

[GI4DOH]

I've been trying to get my Elgato Camlink 4K HDMI dongle to work with my LimeSDR Mini and Portsdown 4 with build 202209280. I note the original post here refers to 202209070 but I assume this functionality has been carried forward.

With a 720p HDMI input from my Repeater Controller and Ryde combination the HDMI Monitor function on the Portsdown 4 is fine regardless of any movement like receiving an animated testcard or camera input. Maybe irrelevant but this HDMI feed I believe is at 60Hz.

If I transmit from the Portsdown 4 with output to LimeDVB, S2QPSK, 1000ks and 2/3 FEC, the received signal with a Minitioune Rx and PC is notionally OK with a static picture at 4:3, 16:9, 720p and 1080p. Any movement is jerky. Any audio on the HDMI input is very broken up.
With the animated testcard, 720p is the best result but it is still very jerky and disjointed.

I haven’t had any joy with the Portsdown 4 HDMI Repeater TX Card Setup when following to the letter.

Using a HDMI to AV converter feeding an EasyCap gives much better results apart from the obvious degradation of quality through the extra conversion stage.

Ultimately what I am trying to achieve is an HDMI-input repeater transmitter. I can already stream to the streamer with a Chinese encoder.

Is there anything obviously wrong in the above or any other advice?

Richard GI4DOH

[G8GKQ]

Hi Richard

Please confirm that you have the HDMI Dongle connected to the RPi through a USB3 lead and that you are using the the USB3 input on the RPi?

Dave

[GI4DOH]

Indeed I have thanks Dave - I learnt that one very quickly - it doesn't like ordinary leads.
But you have raised a good point - my LimeSDR mini which is inside the box with my Portsdown 4 may well not be USB 3 although it goes to the other RPi USB 3 socket.
Richard GI4DOH

[G8YTZ]

Hi Dave,

Camlink works well with RF on a native headless Portsdown and also via the Jetson nano, but for some reason I don't get audio when I use the stream output (native Portsdown Headless).

Is this an expected behavior, my finger trouble or a bug?

Justin.

[G8GKQ]

Expected behaviour. The audio is very difficult to capture.

Dave