[BUG] Multi cam not working on main image

[Rylan-Meilutis]

Describe the bug
Multiple webcams do not work when the CAMERA_DEV variable contains more than 1 entry

Container Details

2024-06-18T08:11:07.371Z

To Reproduce
Steps to reproduce the behavior:

1. add multiple camera devices to the container and to the CAMER_DEV variable
2. run the image

Expected behavior
multiple camera streams are created

Additional context
docker compose file

  octoprint:
    image: octoprint/octoprint
    restart: always
    ports:
      - 8080:80
    devices:
      - /dev/ttyACM0:/dev/ttyACM0
      - /dev/video2:/dev/video0
      - /dev/video0:/dev/video1
    volumes:
     - ./octoprint:/octoprint
     - /etc/localtime:/etc/localtime:ro

    environment:
      - ENABLE_MJPG_STREAMER=true
      - CAMERA_DEV=/dev/video0, /dev/video1

I see this in the logs

MJPG Streamer Version.: 2.0
[services.d] done.
 i: Using V4L2 device.: (null)
 i: Desired Resolution: 640 x 480
 i: Frames Per Second.: -1
 i: Format............: JPEG
 i: TV-Norm...........: DEFAULT
 i: init_VideoIn failed
MJPG Streamer Version.: 2.0
 i: Using V4L2 device.: (null)
 i: Desired Resolution: 640 x 480
 i: Frames Per Second.: -1
 i: Format............: JPEG
 i: TV-Norm...........: DEFAULT
 i: init_VideoIn failed

[darderik]

That's because the way that the mjpg launch command gets formatted is just wrong. I don't know what happened there but there was a commit (#245) that tried to fix this, which was reverted. One must launch a mjpg streamer instance for each camera device. I use this code which copies the unaccepted pull request
(mjpg-streamer/run)

#!/usr/bin/with-contenv bash

# Check if the deprecated environment variable MJPEG_STREAMER_INPUT is set
if [ -n "$MJPEG_STREAMER_INPUT" ]; then
  echo "Deprecation warning: the environment variable '$MJPEG_STREAMER_INPUT' was renamed to '$MJPG_STREAMER_INPUT'"
  MJPG_STREAMER_INPUT=$MJPEG_STREAMER_INPUT
fi

# Ensure MJPG_STREAMER_INPUT contains a valid entry
if ! echo "$MJPG_STREAMER_INPUT" | grep -q "..so."; then
  MJPG_STREAMER_INPUT="input_uvc.so $MJPG_STREAMER_INPUT"
fi

# Split the CAMERA_DEV variable into an array of devices
IFS=',' read -ra CAMERA_DEVS <<<"$CAMERA_DEV"
PORT=8080  # Initial port

# Start mjpg_streamer for each camera
for CAMERA in ${CAMERA_DEVS[*]}; do
  echo "Starting mjpg_streamer for camera ${CAMERA} on port ${PORT}"
  mjpg_streamer -i "/usr/local/lib/mjpg-streamer/${MJPG_STREAMER_INPUT} -d ${CAMERA}" \
                -o "/usr/local/lib/mjpg-streamer/output_http.so -w /usr/local/share/mjpg-streamer/www -p ${PORT}" &
  PORT=$((PORT + 1))  # Increment the port for the next camera
done

# Wait for all background processes to complete
wait