Projector Render Display Filter - increase maximum allowed delay

jjwyndham

New Member
Good morning,

Our church uses a format where we have picture in picture, with one of the pictures being our slides and the other being an audio/visual feed from our cameras (Marshall CV-630) and sound board (Behringer X32). On our live streams, there is a significant offset between our projector render (instantaneous) and our audio/visual feed (approx. 2-second delay), which causes our on-line viewers to see the slides advancing well before the audio/visual feed is advancing. We have maxed out the "Render Delay" filter on the projector source at 500 ms, but we need for it to be closer to 2000 ms. Could someone please make this change to the filter? Thanks.

Jeremy
admin@stnickshillcountry.org
+1-214-577-5334
 

AaronD

Active Member
At the very least, you could stack up 4 of those filters. They all run in series, one feeding the next, which also means that certain picture adjustments can also depend on the order...

Though if you have *that* much latency, I'd look at getting the slow source closer to real-time. Maybe you need a different device...
 

jjwyndham

New Member
At the very least, you could stack up 4 of those filters. They all run in series, one feeding the next, which also means that certain picture adjustments can also depend on the order...

Though if you have *that* much latency, I'd look at getting the slow source closer to real-time. Maybe you need a different device...
Thanks, Aaron. We'll try the serial filters and see how that works. In terms of the devices, the cameras otherwise perform well, so I think it is related to the fact that the slides are resident on the streaming computer, and the audio and video are coming to that computer via network cables through a switch (video) and via a USB cable (audio). I don't think we'd be able to fix these delays since we want to continue to run the audio/video this way.
 

AaronD

Active Member
Just for reference, we have two SDI cameras, one WiFi camera on stage (phone app), and a separate slides PC. About 1/4 second latency on Ubuntu Studio Linux.

The SDI cameras and the slides PC come into a 4-input PCIe card. The slides PC goes through an HDMI -> SDI converter and a 3-ft coax, just to still use that card.

Originally, that rig converted the cameras to HDMI in the booth, and then had 4x HDMI -> USB captures. Those were random latency, so the cameras never lined up with each other. The 4-input internal card fixed that, *and* reduced the average latency. The Sync Delay on the USB line input from our X32 went from 500ms with the 4 USB's, to 300ms with the internal card.
(The X32's 32-channel USB card is used for multitrack recording on the sound guy's laptop, so it's not available to stream, plus OBS makes a royal mess of that many channels anyway.)
 

jjwyndham

New Member
Thank you for the additional insights, Aaron. While the cameras we use do have the SDI and HDMI outputs (https://marshall-usa.com/cameras/CV630-IP/), I am hesitant to use those since we are trying to keep our space as flexible as possible by using the Ethernet connections. We shift our space around based on the church season and the number of people we are trying to fit into the space. Therefore, the location of the sound booth (and the altar and musicians) moves around, and I don't want to have to reroute SDI or HDMI cables every time we adjust the layout of the worship space. I'll check with my IT guy to see if there is anything we can do to reduce the latency across the Ethernet connections, and I'll try the serial filters.

By the way, I am impressed with your stream. I like how you move around from camera to camera to keep the live feed interesting. I will probably try that as well. I case you are interested in checking out our stream, we are on YouTube (among other platforms) at: https://www.youtube.com/@st.nicholas9163/streams. I'd enjoy continuing to share ideas with you.

Thank you for all you do for Harvest Ridge and this OBS community as well.

Jeremy
 

AaronD

Active Member
I case you are interested in checking out our stream, we are on YouTube (among other platforms) at: https://www.youtube.com/@st.nicholas9163/streams.
Nice! You're coming along pretty well too.

We shift our space around based on the church season and the number of people we are trying to fit into the space. Therefore, the location of the sound booth (and the altar and musicians) moves around, and I don't want to have to reroute SDI or HDMI cables every time we adjust the layout of the worship space.
What *is* your space? When you finally get to the wide shot (good storytelling, by the way: close shots for a while to keep me guessing, then reveal later), I see corrugated siding, two roll-up garage doors with the projector in between, and what look like a permanent-mounted projector and camera together.

For a while, we had a different church meet in our building on Sunday afternoons, that grew up meeting in a school. They had all their own gear, and loaded in and out every Sunday. That included a quite capable A/V rig! The school decided to repaint as the Covid lockdowns were easing up, and kept them out for that.

They never used all of their stuff while they were with us - they used most of ours and added some of theirs to it - but I did see that their "custom closets on wheels" had several large reels of Cat-5 and coax, with RJ-45, Ethercon (RJ-45 inside an XLR-size shield), and BNC. X32 on a cart, and S16 in the portable rack that they put on stage. They also had a formalized and trained setup and teardown team.

Don't know if that would fit your mold or not, but based on what I saw from them, if you're running cords anyway, you might as well run the good stuff.

By the way, I am impressed with your stream. I like how you move around from camera to camera to keep the live feed interesting. I will probably try that as well.
My major technique is to minimize camera movements while live. *Sometimes* I'll break that rule, like to follow someone or to make minor framing tweaks, or on a rare occasion, gently pull or push, but that's about it. I especially don't like zipping to a new center while the zoom isn't anywhere near caught up yet. I have before, manually set the zoom and then hit the preset while the zoom is still running, just to give it a head start. That looks a *little* bit better to me, but still not great.

---

I'd enjoy continuing to share ideas with you.
:-)

Our audio is compressed hard! In several stages. Then brought up to full-scale as the USB line input sees it. You might make a valid argument for killing the "live" feel, but that's the broadcast standard that viewers expect. Here's the scene file that gets pushed into our X32 when it appears on the network. (after a 2-hour timeout of being off, so a brief power hiccup doesn't wreck it!) And one of the Sunday morning scenes that builds heavily on it.

You might notice that the final output level is about -12dBFS peak, according to the settings, and that's because our line input uses the consumer standard whereas the X32 uses the pro standard line level. About 11dB difference between those. So it *is* actually full-scale coming into OBS...or -1dBFS, which is pretty close.

Matrix 1-2 are our Broadcast Master.
Matrix 3 is our Lobby and Hearing Assistance. (broadcast minus room mics)
Matrix 4 is our PA Center. The 60Hz highpass is for woofer protection without subs. Set by ear with pink noise, right on the edge of making an audible difference.
Matrix 5-6 are reserved for a possible PA Left-Right that we don't have yet.
Matrix 5 is temporarily a stage fill that is normally kept off/muted.

FX 4 is an approximation to this trick to try and avoid feedback on a speaking mic:
About 17 cents seems to be about right for our specific room; your room might need something slightly different. DO NOT USE IT FOR SINGING!!! ;-)
It's really for special events run by people who have no idea how to handle a mic, and they're not going to learn now. It allows an extra 5dB or so before feedback, in exchange for a slightly odd sound if you pay attention, but still easily intelligible. We don't use it for Sunday service at all.
It's only an approximation because the pitch shifter that the X32 actually has, is a multiplier, while the linked analog project is an adder like it really should be.
FX 1,2,3,5,6 are available for general use

---

Thank you for all you do for Harvest Ridge and this OBS community as well.

Jeremy
:-)
 

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jjwyndham

New Member
Hi, Aaron. Much of what you mentioned above is over my head, but I am going to share it with our A/V team to see what we can earn from your setup. In terms of the space, we (the Episcopal Diocese of West Texas) bought us (we are still considered a church plant so we are part of the diocese) a building that was a bar and grill in Bulverde, TX. Hence the corrugated metal and glass garage doors. As we reconfigured the space, I hired an IT person to put in a network so that all of the A/V could be digital. During parts of the year, we configure the space so that the altar and screen are between the garage doors, and the seats are arranged in a sort of semi-circle (not very efficient, but very inviting and informal). Other times of year, when we either need to fit more people in (Easter and Christmas), or when we want a more formal environment (Lent), we move the altar and screen to the short wall of the space, and arrange the chairs in straight rows using the full length of the space. Because of this desired flexibility, I need to be able to plug the stage box into a network port and also plug the A/V booth into a network port. This allows us to control sound levels, 2 PTZ cameras and the projector through the network. The main issue seems to be that the slides advance instantly on the feed, and the sound/video are delayed due to having to travel through the network to the streaming computer. I've been playing with adding additional Render Delay filters on the projector source, and it does seem to be working better. We'll give that a try on Sunday and see if it works better. We'll also have a look at the files you sent for additional ideas. Thanks again for all of your help. - Jeremy
 

AaronD

Active Member
Ah! That makes sense! Good for you!

I like new and creative stuff too. My favorite services to run were during Covid, and we never did it the same way twice! I loved that!

Anyway, I'd be sorely tempted to run some TV antenna cable or something similar, so you can use SDI from the cameras in each configuration. BNC jack, of course, instead of F-type. Yes, that's more cords to plug in (and an opportunity to swap the cameras by accident), but much more usable I think! Keep the network for control, but not for high-quality low-latency video.
 

jjwyndham

New Member
Thanks again, Aaron. We'll have a look into how we can do that with the video feeds to get better and faster video.
 
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