Android phone as a Webcam on Linux

In this guide, we’ll learn how to create a virtual webcam on a Linux device using an Android device’s camera. We’ll go through the installation of key packages like adb, v4l2loopback, and scrcpy, allowing us to utilize an Android device’s camera as a virtual webcam.

Pre-requisites

An Android phone (Android 12+)
Linux Desktop (scoping to any Debian-based distro for this guide)

Installing required packages

1. `adb`

adb, which stands for Android Debug Bridge, is a versatile command-line tool used for communicating with Android devices directly from your computer. ¹

$ sudo apt install adb

2. `v4l2loopback`

v4l2loopback is a kernel module (software program) for Linux that allows you to create virtual video devices. ²

$ sudo apt install v4l2loopback-dkms

Load the kernel module, setting the exclusive_caps option to 1, and label it as “Virtual Webcam.”

Note: Setting exclusive_caps to 1 is important for Chromium/WebRTC-based tools like Google Meet or Zoom, which requires a webcam device with only capture capabilities

# Load the `v4l2loopback` kernel module
# and set `exclusive_caps` option to `1`
# (important for Chromium/WebRTC-based tools like Google Meet or Zoom,
# which require a webcam device with only capture capabilities)
$ sudo modprobe -v v4l2loopback exclusive_caps=1 card_label="Virtual Webcam"

Verify the creation of the virtual webcam device:

$ v4l2-ctl --list-devices    # or you may `ls /dev/video*`
Dummy video device (0x0000) (platform:v4l2loopback-000):
  /dev/video0

3. `scrcpy`

scrcpy stands for “screen copy” and is a free and open-source tool that allows you to mirror and control your Android device from your computer. It works on Linux, Windows, and macOS, making it a cross-platform solution. ³

# Install pre-requisites for Debian/Ubuntu
sudo apt install ffmpeg libsdl2-2.0-0 adb wget \
                 gcc git pkg-config meson ninja-build libsdl2-dev \
                 libavcodec-dev libavdevice-dev libavformat-dev libavutil-dev \
                 libswresample-dev libusb-1.0-0 libusb-1.0-0-dev

$ git clone --depth 1 --branch v2.3.1 https://github.com/Genymobile/scrcpy
$ cd scrcpy
$ ./install_release.sh  # may ask for your sudo password

Connecting your phone via with `adb`

Enable Developer options using this guide from developer.android.com
Enable USB debugging using this guide from developer.android.com
Connect your Android phone to your Linux computer.
When prompted on your Android device, click on ALLOW to grant USB debugging access.

Verify that your device is detected (device ID may vary):

$ adb devices
List of devices attached
978a27c9  device

Using `scrcpy`

Now that our device is connected properly we can list the cameras ⁴ we can utilize:

$ scrcpy --list-cameras

Example output:

scrcpy 2.3.1 <https://github.com/Genymobile/scrcpy>
INFO: ADB device found:
INFO:     -->   (usb)  978a27c9                        device  DEVICEX
/usr/local/share/scrcpy/scrcpy-server: 1 file pushed. 0.6 MB/s (66007 bytes in 0.100s)
[server] INFO: Device: [make] make DEVICEX (Android 12)
[server] INFO: List of cameras:
    --camera-id=0    (back, 4608x3456, fps=[10, 15, 28, 30])
    --camera-id=1    (front, 3264x2448, fps=[15, 30])
    --camera-id=2    (back, 3264x2448, fps=[15, 28, 30])
    --camera-id=3    (back, 1600x1200, fps=[15, 30])
    --camera-id=4    (back, 1600x1200, fps=[15, 27])
    --camera-id=5    (back, 4608x3456, fps=[10, 15, 28, 30])
    --camera-id=6    (back, 4608x3456, fps=[10, 15, 28, 30])

Start scrcpy with the desired camera source and output to the virtual webcam device:

$ scrcpy --video-source=camera --no-audio --camera-facing=front \
    --v4l2-sink=/dev/video0

v4l2-sink outputs the received video stream into v4l2 device /dev/video0, which we had created earlier.
You may check more available options here scrcpy - camera mirroring

Example output:

scrcpy 2.3.1 <https://github.com/Genymobile/scrcpy>
INFO: Video orientation is locked for v4l2 sink. See --lock-video-orientation.
INFO: Camera video source: control disabled
INFO: ADB device found:
INFO:     -->   (usb)  978a27c9                        device  DEVICEX
/usr/local/share/scrcpy/scrcpy-server: 1 file pushed. 6.9 MB/s (66007 bytes in 0.009s)
[server] INFO: Device: [make] make DEVICEX (Android 12)
INFO: Renderer: opengl
INFO: OpenGL version: 4.6 (Compatibility Profile) Mesa 23.3.2-blah-blah
INFO: Trilinear filtering enabled
[server] INFO: Using camera '1'
INFO: v4l2 sink started to device: /dev/video0
INFO: Texture: 3264x2448
# A new window will pop up which will serve as a viewfinder.

We can now use our newly added Virtual Webcam for video calls and conferences. 🎉

Pre-requisites#

Installing required packages#

1. adb#

2. v4l2loopback#

3. scrcpy#

Connecting your phone via with adb#

Using scrcpy#