Raspberry Pi webcam cannot open video device

Question

Error "Cannot open video device"

I am using an HP Deluxe webcam (EW193AA) with raspberry pi

log lsusb

Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.
Bus 001 Device 006: ID 093a:2621 Pixart Imaging, Inc. PAC731x Trust Webcam
Bus 001 Device 005: ID 413c:2107 Dell Computer Corp.

motion log -n

[0] Processing thread 0 - config file /etc/motion/motion.conf
[0] Motion 3.2.12 Started
[0] ffmpeg LIBAVCODEC_BUILD 3482368 LIBAVFORMAT_BUILD 3478785
[0] Thread 1 is from /etc/motion/motion.conf
[0] httpd bind(): Address already in use
[0] httpd thread exit
[1] Thread 1 started
[1] cap.driver: "gspca_pac7302"
[1] cap.card: "USB Camera (093a:2621)"
[1] cap.bus_info: "usb-bcm2708_usb-1.2"
[1] cap.capabilities=0x85000001
[1] - VIDEO_CAPTURE
[1] - READWRITE
[1] - STREAMING
[1] Config palette index 8 (YU12) doesn't work.
[1] Supported palettes:
[1] 0: PJPG (PJPG)
[1] Unable to find a compatible palette format.
[1] ioctl (VIDIOCGCAP): Inappropriate ioctl for device
[1] Could not fetch initial image from camera
[1] Motion continues using width and height from config file(s)
[1] Resizing pre_capture buffer to 1 items
[1] bind(): Address already in use
[1] Problem enabling stream server in port 8081: Address already in use
[1] Thread exiting
[0] Motion thread 1 restart

I tried to change the width and height to 160 * 140, 320 * 240,640 * 480, but led to the same error .... but cannot find a solution ...

Answer 1

Logfile reports that your port 8081 is already in use ... please also make sure your path is writable by motion.motion: for example. sudo chown motion.motion / home / pi / motion

Answer 2

Try to run:

LD_PRELOAD=/usr/lib/arm-linux-gnueabihf/libv4l/v4l1compat.so motion -n

Answer 3

For me, this ended with a configuration file problem. I set the resolution to 640x360, after a little grunt, I found that the height should be divisible by 16. The initial error message "port is already in use" was incorrect, as evidenced by the fact that the port changes did not fix anything. After I returned to a height of 480, the service reappeared.

I recommend 320x240, 640x480 or 1280x720 (if you have a decent webcam and internet speed).