Programatically send images to v4l2-device

Question

I have a program that generates jpgs. I would like to send these images to my virtual webcam when they are generated. I can create a virtual webcam using v4l2loopback and have been looking at gstreamer, but can't quite get it to work.

I've tried gst-launch with multifilesrc, but that seems to only work when I have images already generated. I've also tried setting gst-launch to just send one image to the webcam and then just overwrite the image when a new one is generated. This, unfortunately, causes gstreamer to crash.

Does anyone know how I might be able to do this? I don't have to use gstreamer, but I am looking to do implement this in Linux, ideally in Python.

Answer 1

the following script will monitor a directory and pass every newly added image to gstreamer which will send it to the video-device (/dev/video0, but change at will).

call with the path to monitor as the sole argument (e.g. ./pics2v4l2 /tmp/pics)

#!/bin/sh

DIR=$1
DEVICE=/dev/video0

inotifywait -m "${DIR}" \
| awk '$2== "CLOSE_WRITE,CLOSE" {print $1"/"$3; fflush()}' \
| while read f; do
 gst-launch-0.10 uridecodebin uri="file://${f}" \
 ! ffmpegcolorspace \
 ! videoscale \
 ! imagefreeze \
 ! identity error-after=2 \
 ! v4l2sink show-preroll-frame=false device=${DEVICE}
done

Answer 2

Script for gst-launch-1.0

DIR=$1
DEVICE=/dev/video0

inotifywait -m "${DIR}" \
| awk '$2== "CLOSE_WRITE,CLOSE" {print $1"/"$3; fflush()}' \
| while read f; do
 gst-launch-1.0 uridecodebin uri="file://${f}" \
 ! videoconvert \
 ! videoscale \
 ! imagefreeze \
 ! identity error-after=2 \
 ! v4l2sink show-preroll-frame=false device=${DEVICE}
done

Execute using

sh <FILE_NAME>.sh <DIRECTORY_PATH>