This page is about how to use the Logitech C270 Webcam with Linux, in this case Debian Buster. This is a cheap webcam I bought to play with video but at the time I did not know whether it would be easy to use with Linux or require a lot of hacking. In short, this camera is immediately recognised by V4L2 (Video4Linux) which means it is not difficult to get working.
[ 3451.085375] usb 3-2: new high-speed USB device number 6 using xhci_hcd [ 3451.450828] usb 3-2: New USB device found, idVendor=046d, idProduct=0825, bcdDevice= 0.12 [ 3451.450830] usb 3-2: New USB device strings: Mfr=0, Product=0, SerialNumber=2 [ 3451.450830] usb 3-2: SerialNumber: (redacted) [ 3451.451543] uvcvideo: Found UVC 1.00 device <unnamed> (046d:0825) [ 3451.565876] input: UVC Camera (046d:0825) as /devices/pci0000:00/0000:00:14.0/usb3/3-2/3-2:1.0/input/input32 [ 3452.935792] usb 3-2: set resolution quirk: cval->res = 384
At this stage the camera seems to be working well.
Using ffmpeg for recording images or video seems to be a convenient solution for many tasks.
List v4l devices:
ffmpeg -f v4l2 -list_formats all -i /dev/video0
Change the /dev/video0 part to whatever worked for VLC. We can see the camera supports raw acquisition in YUYV 4:2:2 colour space or you can use the onboard MJPEG encoder:
[video4linux2,v4l2 @ 0x5631fbb20380] Raw : yuyv422 : YUYV 4:2:2 : 640x480 160x120 176x144 320x176 320x240 352x288 432x240 544x288 640x360 752x416 800x448 800x600 864x480 960x544 960x720 1024x576 1184x656 1280x720 1280x960 [video4linux2,v4l2 @ 0x5631fbb20380] Compressed: mjpeg : Motion-JPEG : 640x480 160x120 176x144 320x176 320x240 352x288 432x240 544x288 640x360 752x416 800x448 800x600 864x480 960x544 960x720 1024x576 1184x656 1280x720 1280x960
Grab 4 seconds of webcam as an anim gif:
ffmpeg -f v4l2 -framerate 25 -video_size 640x480 -i /dev/video0 -t 00:00:04 output.gif
Wait 4 seconds then grab a single image:
ffmpeg -ss 4 -f v4l2 -framerate 25 -video_size 640x480 -i /dev/video0 -frames:v 1 output.jpg
Why wait 4 seconds? The camera needs to start and set auto gain.
If you are running a webserver that has PHP access then you can create an online webcam by modifying the following scripts and copying them to suitable locations.
webcam.php
<html>
<head>
<title>My Webcam</title>
<meta http-equiv="refresh" content="5">
</head>
<body>
<?php exec("/path/to/grabframe.sh"); ?>
<h1><?php echo date("Y-m-d H:i:s",time()); ?></h1>
<span style="text-align:center">
<img src="webcamframe.jpeg">
</span>
</body>
</html>
grabframe.sh
#!/bin/bash cd /location/of/above/php/script ffmpeg -y -ss 4 -f v4l2 -framerate 25 -video_size 640x480 -i /dev/video0 -frames:v 1 webcamframe.jpeg
For gstreamer it is assumed you have installed all the necessary codec packages and extensions.
If you know the video device will be /dev/video0 then you can skip this parameter in the following as video0 is the default. The frame rate will probably be a bit choppy without any set up:
gst-launch-1.0 v4l2src device=/dev/video0 ! xvimagesink
Setting some parameters will give better resolution:
gst-launch-1.0 -v v4l2src device=/dev/video0 ! video/x-raw,width=1280,height=720 ! xvimagesink
In raw mode the frame rate is limited unless you drop resolution, like so:
gst-launch-1.0 -v v4l2src device=/dev/video0 ! video/x-raw,framerate=30/1,width=640,height=480 ! xvimagesink
Switching to MJPEG mode allows those higher resolutions:
gst-launch-1.0 -v v4l2src device=/dev/video0 ! image/jpeg,framerate=30/1,width=1280,height=720 ! jpegdec ! videoconvert ! autovideosink