More than one HDMI over IP sender in the same network?

[eriklanden]

I have an idea for develop our sports streaming setup. Today we have IP-cameras that runs over a PoE network. We cover a Mountainbike track that is over 4km long and we want to add 3-4 videocameras along the track. I have been researching HDMI over IP that seems to be a solution, except that all extenders I can find only works with only one sender and multiples receivers. Guess the main purpose is to distribute one TV signal to a lot of TVs and such, not like I want to do, just send multiples HDMI streams to specifik receivers. Any idea on how to solve this? This is a sketch on how I think.

 

[eriklanden]

Maybe this is a complex solution? If every camera was connected to a Raspberry Pi or similar that just converts the HDMI to a RTMP stream directly over the Network? That will put more load on the CPU in the streaming computer that is all ready struggleing with 12 IP-cameras, but might work ?

 

[Lawrence_SoCal]

If you already have IP PoE camera(s), why go backwards with HDMI to a conversion box to the network? That presumes network cabling, so why not stick with IP PoE?
Is this a case of having electricity distributed around site, but not network? Due to distances involved, you may need/benefit from fiber optics for some of the cable runs. If you have an electricity available nearby the desired camera locations around the track, you could use a PoE injector to power camera, or just run power direct to camera and skip PoE, whichever cabling option is easier. Of course, beware running electricity in parallel, within 12", of typical Ethernet cable (so definitely not in same conduit or even thin trench (without adequate shielding... and I don't know what exactly it would require, and in part it would depend on Watts being run, which could be significant for night riding with large stadium halogen bulbs... ymmv )).
Also, you image shows 120m CAT5e/6 cable, and that may well work, but as I recall the Ethernet cable spec is 100m, and that includes 5m on each end for patch cable. So, you'd have to test, and be aware that if a connection at 120m cable length stops work, it may well still be within spec.
Technically possible but not a good idea, to avoid using Fiber optic cable runs, would be to daisy-chain small PoE switches around the track. A single switch failure, close to home base, would take down the whole network. And you'd need to be careful with latency on the all hops and throughput capability. basically .. beware cheap/consumer grade gear. And I'd want to test all the gear, with actual cable lengths in a room before actually deploying and having to run around the track trying to troubleshoot issues. Fiber cable and fiber transceivers aren't that expensive, and would let you run all cable back to base, meaning a connection problem would only impact 1 camera

 

[eriklanden]

As you say the PoE network is in place, but this is just fixed cameras. We want to add cameras that is controlled by a person to have more than static footage. So my thought was having 3-4 persons around the track operating a simple videocamera with HDMI out and in some way send that signal over the network. This way we can cover a lot more of the races, zooming and panning.

The 120m in the image was just a sample image from the LKV373A V4.0 HDMI extender. Our cables are never longer than 100m. We use switches for some cameras to extend the cable.

Are there any videocameras that can be operated by a person with PoE and that puts out a RTSP stream or simliar that can be fetched from OBS? Or do you refer to a PTZ camera? We are on a budget and all ready have cameras with HDMI out that is not used in this setup so that is why I went this route.

Happy to explore other solutions also, out next race is in may 2023 so :)

 

[eriklanden]

Here is a video of our stream this year, could be improved a lot with some zooming and panning cameras I think.

- YouTube

Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.

youtu.be

But again the problem is distance, some of the cameras in the footage here is 700m from the computer that streams.

 

[eriklanden]

After som more research I think a NDI converter is the way to go. HDMi → NDI. Then I only need that device at the camera and OBS can fetch the NDI signal without a capture card. Less things that can go wrong :)

 

[Lawrence_SoCal]

If PoE network in place and functioning with fixed cameras, then you have already overcome the Ethernet cable length and overall distance issue (right?)

If so, my thinking is the following
- large budget - consider PTZ NDI cameras, all centrally controlled
- if small budget and volunteers available... would simply putting the fixed position cameras on a gimbal/tripod, and having operator move the camera suffice?
the benefit of local camera operator is ability to 'see' (and hear) action outside of camera view and move as appropriate (ex, sound of approaching bikes, or a crash, or ??). The downside is training and skill (muscle motor control for smooth panning motion) of camera

PTZOptics just announced development (Beta) of a PTZ Camare control software that will include motion tracking. Now, whether that could handle motorsport speeds is a separate question (vs person walking across stage). But I could (getting fancy) envision 2 cameras per location (or overlapping fields of view); with a wide-angle lens, and a 2nd PTZ camera, with an operator having option to click on bike as it enters field of view, then click track, and let the camera follow the action/motion? Not sure this is practical... I'm trying to think of a way to overcome the lack of broader situational awareness for central camera operator(s), hence pondering a wide-angle view in addition to PTZ view.

 

[eriklanden]

The PTZ NDI cameras is really interesting put a bit over our budget. Maybe if we get a sponsor for the live feed that we can overlay an all those cameras. The problem with our setup and let a volunteers operate them is that it is IP-cameras (Reolink) with no screen. Here are the cameras we used.

 

[Fbosman]

These reeling camera's supply also a rtsp feed. As you have an ip-network in place you could use OBS's native rtsp receiving or use g-streamer. The latter one will give you less latency.
This way you will not need any converters.

 

[Lawrence_SoCal]

In a MacGuyver vein (ie not recommending, just thinking aloud, so-to-speak) would be to mount a small glass/transparent plate along with the cameras and mark out on that plate the field of view for the camera ... that would/should cover rough 'framing' and I'd think be good enough
I'm thinking some sort of L-bracket with base plate in-between tripod mount and camera base.
Then the tall portion going just up above the camera itself, such that looking through clear plate (plastic, glass, whatever) with markings for field-of-view, (like in a rangefinder camera) would help camera operator point camera in right direction
want to get really fancy and have access to right equipment... have that L bracket point forward, with only arms going up on either side (just wide than lens body).. with a square-ish 'viewfinder'. When not in use, that viewfinder could rotate down 180degress and act as lens cover ;^)

As noted above, those cameras use RTSP, and low/consistent latency is NOT important for such devices/manufacturers. I suspect that won't matter, but something to be aware of. And with budget considerations, I'd recommend against mixing RTSP and NDI.
There are PTZ security cameras that would be much cheaper than NDI (with higher and slightly inconsistent latency, and lower optical quality... but maybe meet your needs??). NDI PTZ cameras cost a lot more, and you get more for that money. just depends on what you need and can afford
Hopefully those security cameras are at least 30fps, not the really cheap 15fps models

 

[eriklanden]

Yes, we use the RTSP stream today from the cameras shown above. Why is it bad to mix RTSP and NDI?

Like the idea of range-find-equip the cameras :) Yes the cameras are 30FPS, I have set the resolution to match as close to 720p as possible then frame it in OBS (they use some odd resolutions). It could work for some of the cameras, but still I think they are best for static shots.

Some scenes could really benefit from a long zoom. We have this hill that takes like 2 min and with a decent zoom-camera we could follow the riders all the way, not just on the top. So we would maybe start with 2 or 3 videocameras to complement the Reolink IP-cameras.

Just need to figure out how to best send the signal via network.

 

[Lawrence_SoCal]

Yes, we use the RTSP stream today from the cameras shown above. Why is it bad to mix RTSP and NDI?

Because you'll have 2 different software receivers on the OBS PC, and the cameras will have mis-matched latency
If computer is powerful enough (RAM, etc), and cameras are seeing same ground/field-of-view, and you have the network and technical expertise to manage both, and the differences... maybe... but otherwise you are just adding complexity

Some scenes could really benefit from a long zoom. We have this hill that takes like 2 min and with a decent zoom-camera we could follow the riders all the way, not just on the top. So we would maybe start with 2 or 3 videocameras to complement the Reolink IP-cameras.

This is where I'm saying there are RTSP-based security cameras with PTZ capability.
Or you could get a 4K camera and use an OBS plugin to create a smooth zoom action?

Just need to figure out how to best send the signal via network.

I guess this is the part I don't get. You already have the network. I'm saying to stick with the network technology you are already using.
I suppose a constraint would be if you only have a 100Mb/s vs 1GbE network?
- realize each camera will add bandwidth, so overall network switch(es) and PC need appropriate capacity (you'll need to monitor)
- NDI cameras will tend to be higher resolution, and therefore more bandwidth (in general, there are options). There are newer video compression algorithms which use less bandwidth, but will require more computation to decompress incoming video feed from cameras [ie a trade-off]

My thinking is that if you have a PoE Ethernet connection at location X, the question is coming up with a small Ethernet switch powered by PoE and pass along to camaras and all of that fitting in PoE budget. You may have to look at PoE+. Then again, you could swap out some come static cameras for RTSP PTZ cameras (after confirming PoE power budget) and be good to go?
What I don't know and am bouncing around is whether you have an AC outlet near the camera location, or if the only power is via PoE/single Ethernet cable

Also, for that long climb view, I suspect you will have riders at different positions, so zooming in to focus on lead group/person, would then exclude group behind. Have you looked at the ReoLink PTZ cameras? like their 4K dual-lens PTZ camera with motion tracking? or maybe their RLC-842A.. lots of options

Keeping to a single camera vendor helps with troubleshooting and vendor support (avoiding finger-pointing)

 

[Fbosman]

We mix fixed Reolink camera’s an Axis ptz camera and a jvc ptz camera, all use rtsp and they have the same latency over the 1G lan and Poe+ switches. It all depends on the quality you want and need. We have full HD at 25fps and that’s good enough. You might need a higher fps.

 

[eriklanden]

I guess this is the part I don't get. You already have the network. I'm saying to stick with the network technology you are already using.
I suppose a constraint would be if you only have a 100Mb/s vs 1GbE network?

I understand, it is a bit confusing I guess. Since we can get hold of video-cameras from members of the club it would be a cost effective solution and also probably bump the video-quality a whole lot, since Reolink is OK but not great for fast moving cykling.

We have AC near the cameras since PoE switches run of a gasoline generator, so to power a camera a whole day would be no problem. For extend the the signal around the track we use simple Gbit switches 5V that runs of of USB-powerbanks 20 000mh. Hopefully everything is Gbit next year, the last two years the PoE switches are 100Mbit and the extend switches are 1Gbit, since Reolink only is 100Mbit anyways, but I guess it makes sense to have some room in the network when we are adding more things.

 

[eriklanden]

We mix fixed Reolink camera’s an Axis ptz camera and a jvc ptz camera, all use rtsp and they have the same latency over the 1G lan and Poe+ switches. It all depends on the quality you want and need. We have full HD at 25fps and that’s good enough. You might need a higher fps.

We have streamed both 25 and 30 FPS. One year we teamed up with a production company and they used our gear with ours and then we went for 25, but last year when we only used our fixed camera and had a lower budget we went for 30 FPS. Both times at 720, when looking in Youtube studio like 85-90% was viewing the stream in their phone anyways so I guess 720 is ok. Do you have any example from your stream how it can look with PTZ cameras?

 

[Fbosman]

We stream services from our main church, here is an example: https://youtu.be/SR0lexKndj0

 

[Lawrence_SoCal]

When I mentioned my recommendation to avoid mixing technology, I'm referring to NDI vs RTSP. Different RTSP camera vendors is still same video transmissions (and s/w receiver) technology (at least same family vs something completely different requiring a different receiver like NDI)

As for 100Mb/s vs 1000Mb/e (1GbE) - the issue isn't in the camera to network link. Its once you start consolidating links. that is, without a network drawing, you r mention of course size, and cable runs kept within spec.... I'm assuming farthest camera connects to network and cable runs to next closest camera/network drop location, and then 2 video feeds continue down network link to next switch, etc... Depending on resolution, frame rate, and video compression codec (H.264, H.265, or ??) will determine the network bandwidth consumed per camera video feed. You do run the risk of exceeding a 100Mb/s link with too many cameras.

NDI, being designed for higher fidelity use, will typically use more bandwidth that RTSP (though is configurable)

I totally get volunteer/non-profit budget considerations. But buying HDMI (or whatever as not everyone's home video camera will support same output options) to network adapters won't be free. And an upper-end PTZ RTSP Security camera is in the area of ~$200 (and less sophisticated models less, which approaches supported HDMI to RTSP adapter pricing??). I do see cheap HDMI to RTSP adapters, but beware those don't become more hassle than they are worth
Though not common, maybe ask if someone has home PoE PTZ Security camera (that supports at least 25/30 fps) they'd be willing to unplug and bring to event? at least for initial testing?

 

[Tomasz Góral]

If you need run more like one HDMI over IP, you need manged switch with vlan.
Every adapter run in own network.
Simple if know how work network.

 

[Lawrence_SoCal]

I suspect these are simple, unmanaged switches along the cable route, meaning you'd have to upgrade all of them to support VLANs.
VLANs certainly help to isolate traffic, but in this scenario, unless there was a specific problem to solve, with such limited devices, I'd recommend (based on this thread so far) avoiding the complexity of VLANs (even though I have more than a handful of VLANs in my own home). In this case, it really isn't a security concern, so unless doing Quality-of-Service throttling, which you'd want to avoid anyway, I can't see reason for VLANs. *IF* some of the (presumably HDMI to network) adapters were cheap/unmanageable, and you wanted to use VLAN QoS to throttle video feed per camera... then maybe... but then again, considering network switch upgrade/replacement cost, vs simply getting a properly manageable adapter .... which I'd bet would be cheaper

To me this boils down to
1. desiring better video feed options than statically placed RTSP security cameras provide
2. Most likely, Ethernet/IP network would be fine if adding some additional cameras, using approx same bandwidth per camera video feed (keeping any 100Mb/s switches out at the far edge of the network)
for reference, My Panasonic NDI PTZ camera is using under 30Mb/s for a 1080p60 video feed
3. Adding cameras will involve some cost regardless, with cheapest option being to continue to use existing Ethernet network, with additional connections (which I'm assuming 1-2 additional network ports are available per switch?)
possible extra power required for additional PoE devices
4. Mixing video feed technology (away from RTSP) will complicate matters. Might be fine, might not... depends
5. So that leaves

• creating range finder for existing cameras to assist in framing shot
• volunteer provided camera (hopefully a common 1080p30 HDMI video output) but risk of needing different adapters for different cameras
• Assuming #3 above, and further presuming HDMI to RTSP adapters [as a quick search seemed to result in HDMI to NDI adapters at 2x on the low-end (no name, questionable if any support) to 4X price (for reputable companies)] of HDMI to RTSP adapters?? ymmv.. more research justifiable
  • which to get would depend on technical expertise of person/people setting the system up.. ie, with greater expertise, possibly ok to get lower-cost (self-supported) devices
• At that point, I'd recommend comparing cost of chosen adapters vs cost of desired PoE RTSP PTZ camera.
  • My thinking is I'd rather get a $150-200 IP PoE PTZ camera than borrow a video camera and get a $100-150 adapter
  • As for RTSP / Security camera video feed quality ... that would require testing... not all RTSP/IP Security cameras are the same (and even the cameras you have may have optimizations available)
  • My Panasonic NDI camera with 22X optical zoom is a US ~$2,000 camera, with dynamic range, color fidelity, low-light capability, latency, focus time, smooth motor movement, etc to match.. But outdoors, many of that may not be important for this use case. Oh, and my Panasonic NDI camera is an indoor model, easily damaged by moisture. There are however, so no-name knock-off similar cameras for around 1/2 price

As I type all of the above, I suspect it comes down to
1. Is there an IP PoE Security camera that provides a video feed with quality to match your desires/needs/expectations?
If yes, then
- that should be cheaper than NDI (by a lot), your primary other option
- get/use such cameras as budget allows, and move existing cameras to shots/angles where they suffice
just recognize that security camera design is NOT for quality color video feed live watching (ie 'broadcast')
Unfortunately, especially in today's world of online purchasing, there are few places to go and see different NDI and IP Security cameras setup in same environment, and be able to directly compare them... any near-term trips planned to NYC (B&H) or Tokyo (Yodobashi)? ;^)

2. A consideration with PTZ cameras is who will control them. I mention as controlling multiple cameras is its own skill. Fortunately, there are many options for this, and I've read of options where you can have multiple people controlling different cameras (for example from tablets.. ie Person A controlling Cameras 1 &@, Person B for #3 &4, etc... or whatever.. mix 'n match). The downside to a PTZ camera is that local control (as a home video camera would have) is not part of the local physical controls. You could have a person standing by the PTZ camera with control device (but... adds a whole can of worms with type of control, being able to know the camera framing, etc)

anyway.. thanks for the distraction.. fun to contemplate and think through

 

[eriklanden]

When I mentioned my recommendation to avoid mixing technology, I'm referring to NDI vs RTSP. Different RTSP camera vendors is still same video transmissions (and s/w receiver) technology (at least same family vs something completely different requiring a different receiver like NDI)

As for 100Mb/s vs 1000Mb/e (1GbE) - the issue isn't in the camera to network link. Its once you start consolidating links. that is, without a network drawing, you r mention of course size, and cable runs kept within spec.... I'm assuming farthest camera connects to network and cable runs to next closest camera/network drop location, and then 2 video feeds continue down network link to next switch, etc... Depending on resolution, frame rate, and video compression codec (H.264, H.265, or ??) will determine the network bandwidth consumed per camera video feed. You do run the risk of exceeding a 100Mb/s link with too many cameras.

NDI, being designed for higher fidelity use, will typically use more bandwidth that RTSP (though is configurable)

I totally get volunteer/non-profit budget considerations. But buying HDMI (or whatever as not everyone's home video camera will support same output options) to network adapters won't be free. And an upper-end PTZ RTSP Security camera is in the area of ~$200 (and less sophisticated models less, which approaches supported HDMI to RTSP adapter pricing??). I do see cheap HDMI to RTSP adapters, but beware those don't become more hassle than they are worth
Though not common, maybe ask if someone has home PoE PTZ Security camera (that supports at least 25/30 fps) they'd be willing to unplug and bring to event? at least for initial testing?

This event is now coming closer and again starting to look into it. We might have the possibility to get sponsored with high end cameras (only HDMI). The ideal solution would be something like Panasonic HC-X2000 that would stream directly to RTSP. But if we only can get hold of HDMI out cameras. You mention that cheap HDMI → RTSP can become more hassle then they are worth, do you have any suggestion on higher end HDMI → RTSP converters, preferable that could power over PoE so only the camera battery is the issue when considering power.