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Virtual Webcam Setup

Turn your webcam into an ASCII art camera. Glif processes each frame through its rendering pipeline and outputs to a virtual camera device that other apps (Zoom, Google Meet, OBS) can see.

Output Modes

Flag Description Use case
--pipe-ppm PPM frames to stdout (with headers) Pipe to ffmpeg -f image2pipe
--pipe-raw Raw RGB24 to stdout (no headers) Pipe to ffmpeg -f rawvideo, lower overhead
--v4l2 <dev> Write directly to v4l2loopback device Linux only, eliminates output ffmpeg process

Linux — v4l2loopback (recommended)

Install v4l2loopback

# Debian/Ubuntu
sudo apt install v4l2loopback-dkms

# Arch
sudo pacman -S v4l2loopback-dkms

# Fedora
sudo dnf install v4l2loopback

Create virtual camera

sudo modprobe v4l2loopback video_nr=10 card_label="Glif ASCII Cam" exclusive_caps=1

Direct mode (recommended, 2 processes)

ffmpeg -f v4l2 -i /dev/video0 -f rawvideo -pix_fmt rgb24 -s 640x480 - 2>/dev/null | \
  ./glif --video 640 480 -f fonts/SFNSMono.ttf --v4l2 /dev/video10 --dark -s 2

Pipe mode (fallback, 3 processes)

ffmpeg -f v4l2 -i /dev/video0 -f rawvideo -pix_fmt rgb24 -s 640x480 - 2>/dev/null | \
  ./glif --video 640 480 -f fonts/SFNSMono.ttf --pipe-raw --dark -s 2 | \
  ffmpeg -f rawvideo -pix_fmt rgb24 -video_size 1280x960 -framerate 30 -i - \
    -vf format=yuv420p -f v4l2 /dev/video10

One-liner with script

./scripts/glif-webcam.sh
./scripts/glif-webcam.sh --src /dev/video2 --dst /dev/video10 --scale 3

Use it

Open Zoom / Google Meet / Discord — select "Glif ASCII Cam" as your camera.

macOS — ffmpeg + OBS Virtual Camera

macOS doesn't have v4l2loopback. Use OBS as a virtual camera bridge:

  1. Install OBS Studio and enable its Virtual Camera
  2. Create a named pipe and feed glif output through it:
mkfifo /tmp/glif_cam
ffmpeg -f avfoundation -i "0" -f rawvideo -pix_fmt rgb24 -s 640x480 - 2>/dev/null | \
  ./glif --video 640 480 -f fonts/SFNSMono.ttf --pipe-ppm --dark -s 2 | \
  ffmpeg -f image2pipe -framerate 30 -i - -f mpegts /tmp/glif_cam
  1. In OBS: add a "Media Source" pointing to /tmp/glif_cam, then Start Virtual Camera

Or use the web demo (works everywhere):

make wasm && cd web && python3 -m http.server 8000

Open in browser, click Webcam, share the browser tab.

Windows — ffmpeg + OBS Virtual Camera

ffmpeg -f dshow -i video="Webcam Name" -f rawvideo -pix_fmt rgb24 -s 640x480 - | ^
  glif.exe --video 640 480 -f fonts/SFNSMono.ttf --pipe-ppm --dark -s 2 | ^
  ffmpeg -f image2pipe -framerate 30 -i - -f mpegts udp://localhost:1234

In OBS: add Media Source with udp://localhost:1234, then Start Virtual Camera.

Or use the web demo (works on all platforms).

Troubleshooting

"Cannot open v4l2 device" — check that v4l2loopback is loaded (lsmod | grep v4l2loopback) and the device exists (ls /dev/video*).

Low FPS — reduce resolution (--width 320 --height 240) or scale (-s 1). The pipeline is fast (~1ms/frame), but ffmpeg decode/encode and v4l2 writes add overhead.

Black output — make sure exclusive_caps=1 is set when loading v4l2loopback. Some apps won't show the feed without it.