Can you help integrate python-openCV to this

[daljeet-hcl]

Hi there, your project is very interesting, I have a question, can you help me please

I read frames an from python bindings to openCV, then do some processing on the frame, I want to send these frames to WebRTC as video with minimum Latency, How can I do it using your webrtc Streamer.

Any hints?

[mpromonet]

Hi daljeet-hcl,

I think a possible way is to use a v4l2loopback device, using opencv you can write to it and next webrtc-streamer could read from it.

Best Regards,

Michel.

[daljeet-hcl]

Thanks Michel, for thequick answer, I will definitely try that.

Is there a better and direct way to write frames directly ? so that the latency is further reduced.

If I use v4l2loopback, then I can simply use a chrome Browser as a streamer which would send the Stream to the viewer Browser, will that have same efficiency as your project ?

Regards Daljeet

[mpromonet]

Hi Daljeet,

If you like to avoid the v4l2loopback, an other approach could be using a other capturer, for instance using zeromq. There is a fork https://github.com/abhikandoi/webrtc-streamer that experiment this way. One advantage using zeromq is to avoid kernel module, after for performance, it needs to make some tests....

Best Regards,

Michel.

[daljeet-hcl]

I decided to go with the v4l2loopback and created a device named "/dev/video1" the following commands which read data from my webCam and write to /dev/video1 worked with webrtc-streamer :

1. gst-launch-1.0 v4l2src device=/dev/video0 ! v4l2sink device=/dev/video1
2. ffmpeg -re -i /dev/video0 -f v4l2 /dev/video1

However when I write to /dev/Video1 using openCV and ffmpeg, I am able to read the /dev/video1 in VLC but it doe not work with webrtc-streamer :

python3 videoWriter.py | ffmpeg -f rawvideo -pix_fmt bgr24 -s 640x480 -r 30 -i - -f v4l2 /dev/video1

Here is my python code of videoWriter:

https://gist.github.com/daljeet-hcl/cd55af7607c475d6f77731dc63e185dd

[daljeet-hcl]

I got a quick solution to my problem, I created two v4l2 loopback devices modprobe v4l2loopback devices=2

then python3 videoWriter.py | ffmpeg -f rawvideo -pix_fmt bgr24 -s 640x480 -r 30 -i - -f v4l2 /dev/video2

redirected output of device2 to device1 : gst-launch-1.0 v4l2src device="/dev/video2" ! v4l2sink device="/dev/video1"

then was able to /dev/video1 sucessfully with webrtc-streamer.

[daljeet-hcl]

Also I found that https://github.com/jremmons/pyfakewebcam works well with webrtc-streamer.

I was able to writer frames from opencv usng pyfakewebcam to v4l2Loopback device and stream it using webrtc-streamer.

https://gist.github.com/daljeet-hcl/9eee797715ac504e1694846d65eb3f78

[mpromonet]

Hi daljeet-hcl, Maybe piping is not a good idea because v4l2 is expected to read a frame in one read. Did you rty to write to v4l2 device in your python code ? Best Regards, Michel.

[daljeet-hcl]

https://github.com/jremmons/pyfakewebcam this project is working fine for me, thanks for such a great and easy to configure project. Let me know if I can help. I am leaning python, but I know Java and a little nodejs.