Question/Help High latency in streaming over RTSP from multiple sources

[obsjug]

I have been trying to consume multiple TP-Link indoor IP camera feeds as input media sources and displaying them using OBS Studio. It's after an exhaustive trial & error that am now posting on the forum. Each of these cameras streams over RTSP. I have created a few scenes so that I can switch between different layouts using the added cameras. But all cameras start streaming out of sync with considerable output latency after a few seconds. Ideally, I would like to achieve sub-second latency using OBS as a rendering solution. Note that I'm only looking to stream the multicam output for now, not record it.

Here's the list of steps I have tried:

+ Relevant settings for OBS Studio:
+ Advanced Settings -> Enable Browser Source Hardware Acceleration

+ Relevant settings for each input media source:
+ Network Buffering: 0MB
+ Reconnect Delay: 1s
+ Use hardware decoding when available: true
+ ffmpeg options: -avioflags direct -fflags nobuffer discardcorrupt -preset ultrafast -tune zerolatency -r 10 -async 1 -noaudio -nocache -vf setpts=0
+ In addition, as recommended in some previous relevant posts, I've also installed DistroAV on NDI runtime, but this didn't help in reducing the delay either.

Here are system details:
Processor: 13th Gen Intel(R) Core(TM) i7-1355U 1.70 GHz
Installed RAM: 40 GB
System type 64-bit operating system, x64-based processor
OS: Windows 11 Pro
OBS Studio version: 31.0.3

Network details:
All cameras are connected via wired LAN to the same system which is using OBS. I've also tried reducing latency using WiFi first, but got no good results.

Log details:

https://obsproject.com/logs/ZB3Lq3Yp3sE5IX75

Log File Analysis: https://obsproject.com/tools/analyzer?log_url=https://obsproject.com/logs/ZB3Lq3Yp3sE5IX75

https://obsproject.com/logs/bCo0gC8U84lRGAuc

Log File Analysis: https://obsproject.com/tools/analyzer?log_url=https://obsproject.com/logs/bCo0gC8U84lRGAuc

One of the log analysis items complains no output session, but I only want to project the output to a monitor, not stream or record it.

Please recommend any solution(s)/suggestion(s) if you have already faced & overcome this issue, I'd be truly grateful for any pointers. Here are some potential pathways:

1. Playing with ffmpeg options
2. A python script to first process the video stream, then to stdout
3. Can I compose the stream using ffplay & then add just the composed stream to OBS studio? How may I go about implementing this?

Here are some threads & links which I've already referred & tried the solutions therein, to no avail:
The most relevant was this one:

Question / Help - Latency on individual media sources causing sync issue

I am using OBS studio to take in multiple IP cameras as media sources. Occasionally, there's a bit of lag from one (or more) of the sources, and just that source stutters for a fraction of a second. However, my issue isn't that there is occasional lag, my issue is that after every small bit of...

obsproject.com

GitHub - DistroAV/DistroAV: DistroAV (formerly OBS-NDI): NDI integration for OBS Studio

DistroAV (formerly OBS-NDI): NDI integration for OBS Studio - DistroAV/DistroAV

github.com

Streaming via custom output (ffmpeg)

Hello, a few weeks ago I've bought an AMD gpu. The first problem I saw is I couldn't record videos in 120 fps on AMF encoder, both AVC and HEVC. Reason I set that high fps is because Twitch supports this kind of framerate without issues. I found encoder doesn't choke when I setup custom...

obsproject.com

Recording with Custom FFmpeg output: How to Set Parameters

I'm using OBS on Linux. I have tried to record screen by integrated graphics card via VAAPI on ffmpeg with the following command: ffmpeg -vaapi_device /dev/dri/renderD128 -f x11grab -video_size 1920x1080 -i :0 -c:v hevc_vaapi -qp 36 output.mp4 This works perfectly, but in OBS's settings pane...

obsproject.com

RTMP source delay

Hi, I have an external camera with RTMP server and I need it as media source input with the smallest possible latency over local network. I've tried setting it up with network buffering set to 0 and FFMPEG options set to "rtmp_buffer=0" and I still notice it accumulates buffering sometimes...

obsproject.com

Inconsistent latency/lag whether streaming, recording, or previewing

Hi all, When I open OBS, the preview window is lagging about 0.5s behind my real-life movements. When I record something, this lag shows up in the recording and I need to offset the audio in VLC to sync them up. But the weird part is the delay is inconsistent. On one recording I need to delay...

obsproject.com

https://obsproject.com/forum/threads/python-script-to-connect-to-obs-websocket-server-help.173395/stream-over-lan-high-latency-with-custom-output-ffmpeg-vs-using-obs-virtual-camera-standalone-ffmpeg.161244/

Attached: Screenshot of the test and log file with one camera setup instead of the 4.

Sorry for the long post, many thanks in advance!