USB camera not working with uv4l Video4Linux

Question

I would like to install a babycam with my Pi so I need video and sound.

After searching I found that Video4Linux might be the best. So I installed a fresh copy of Raspbian Jessie on my Pi 3, attached a Logitech C525 uvc compatible camera.

I installed the following components:

sudo apt-get install uv4l uv4l-raspicam uv4l-server uv4l-uvc uv4l-xscreen uv4l-mjpegstream uv4l-dummy uv4l-raspidisp uv4l-webrtc

dmesg prints out:

[ 6682.548676] uvcvideo: Found UVC 1.00 device HD Webcam C525 (046d:0826)
[ 6682.561664] input: HD Webcam C525 as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3:1.2/input/input4
[ 6688.964105] usb 1-1.3: reset high-speed USB device number 7 using dwc_otg
[ 8940.910267] usb 1-1.3: USB disconnect, device number 7
[ 8945.495112] usb 1-1.3: new high-speed USB device number 8 using dwc_otg
[ 8945.859701] usb 1-1.3: New USB device found, idVendor=046d, idProduct=0826
[ 8945.859722] usb 1-1.3: New USB device strings: Mfr=0, Product=2, SerialNumber=1
[ 8945.859735] usb 1-1.3: Product: HD Webcam C525
[ 8945.859748] usb 1-1.3: SerialNumber: 4D903B20
[ 8946.138421] usb 1-1.3: set resolution quirk: cval->res = 384
[ 8946.139756] uvcvideo: Found UVC 1.00 device HD Webcam C525 (046d:0826)
[ 8946.152736] input: HD Webcam C525 as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3:1.2/input/input5

When I try to start uv4l with this:

uv4l -–driver uvc -–device-id 046d:0826

I'm getting this error:

<alert> [core] No device detected

What am I missing? Or what am I'm doing wrong? The camera works great with mjpeg-streamer on the same Pi.

Answer 1

mjpg-streamer uses the kernel support for V4L2 (/dev/video0). You could probably stream to web with that or gstreamer, but it's understandable that uv4l is simpler to configure for web streaming. (uv4l automatically opens a page on port 8080 if uv4l-server is installed.)

Troubleshooting via tools like v4l-ctl or guvcview would default to using /dev/video0, so those wouldn't be helpful in figuring out what is failing with userspace UVC. I have an Ausdom camera (says "Microdia Camera" when I run lsusb) and it works fine with your command and the corresponding VID:PID, but that doesn't guarantee other cameras work. In truth most userspace libraries for UVC are not without bugs, but uv4l is much harder to debug being closed-source.

For something that sets up a WebRTC stream with the simplicity of uv4l-server and works with the kernel V4L2 driver, try webrtc-streamer. What's more, it comes with source code!

Note: If others here have trouble installing uv4l-server on Stretch, here is a workaround for dealing with older (jessie) dependencies and issues with lrkey.asc:

sudo apt install uv4l uv4l-uvc
sudo apt-get download --allow-unauthenticated uv4l-server
sudo dpkg --install --ignore-depends=libssl1.0.0 uv4l-server_1.1.103_armhf.deb