WebCamHooker

• Web link(Japanese): https://cloud.flect.co.jp/entry/2020/03/31/162537
• Next link: see README2.md

the function using selfie2anime is split to the other repository. if you want to know about this, see https://github.com/dannadori/selfie2anime_webcam_hooker

1. WebCamHooker

Webcamhooker takes the input of a physical webcam and outputs it to a virtual webcam, which can be used to modify images in video chats such as Teams and Zoom.

2. Prerequisite

It should work fine on most Linux systems, but the environment I worked in is a Debian Buster.

$ cat /etc/debian_version
10.3

Also, if you don't seem to have python3 on board, please introduce it.

$ python3 --version
Python 3.7.3

Install related software.

Virtual Webcam Device

This time, we will use a virtual webcam device called v4l2loopback. https://github.com/umlaeute/v4l2loopback

We need to identify the virtual webcam device and the actual webcam, so we first check the device file of the actual webcam. In the example below, it looks like video0 and video1 are assigned to the actual webcam.

$ ls /dev/video*.
/dev/video0 /dev/video1

So, let's introduce v4l2loopback. First of all, please git clone, make and install.

$ git clone https://github.com/umlaeute/v4l2loopback.git
$ cd v4l2loopback
$ make
$ sudo make install

Next, load the module. In this case, it is necessary to add exclusive_caps=1 to make it recognized by chrome. [umlaeute/v4l2loopback#78]

sudo modprobe v4l2loopback exclusive_caps=1

Now that the module is loaded, let's check the device file. In the example below, video2 has been added.

$ ls /dev/video*.
/dev/video0 /dev/video1 /dev/video2

ffmpeg

The easiest way to send data to a virtual webcam device is to use ffmpeg. You can use apt-get and so on to introduce it quickly.

Web camera hooks and video delivery

This time, I'm going to do some image processing once it detects a smile. When a smile is detected, a smile symbol will be displayed on the video.

First, clone the following repository files to install the module.

$ git clone https://github.com/dannadori/WebCamHooker.git
$ cd WebCamHooker/
$ pip3 install -r requirements.txt

Here you will get the cascade file, you can find out more about cascade file in opencv official. https://github.com/opencv/opencv/tree/master/data/haarcascades

$ wget https://raw.githubusercontent.com/opencv/opencv/master/data/haarcascades/haarcascade_frontalface_default.xml -P models
$ wget https://raw.githubusercontent.com/opencv/opencv/master/data/haarcascades/haarcascade_smile.xml -P models

Let's borrow the smile mark from this site.

$ wget https://4.bp.blogspot.com/-QeM2lPMumuo/UNQrby-TEPI/AAAAAAAAI7E/cZIpq3TTyas/s160/mark_face_laugh.png -P images

I hope it has a folder structure like this.

$ ls -1
haarcascade_frontalface_default.xml
haarcascade_smile.xml
mark_face_laugh.png
webcamhooker.py

The execution is as follows. ** --input_video_num should be the actual webcam device number. For /dev/video0, enter a trailing 0. ** --output_video_dev must be the device file of the virtual webcam device. In addition, please use ctrl+c to terminate.

$ python3 webcamhooker.py --input_video_num 0 --output_video_dev /dev/video2

When the above command is executed, ffmpeg starts to run and the video is delivered to the virtual camera device.

Let's have a video chat!

When you want to have a video chat, you should see something called "dummy~" in the list of video devices, so select it.