The driver tries to do detect those cases automatically, but
Windows driver), the uvcvideo driver needs to handle that device in a They forgot to implement parts of the specification that are not used by the When a quasi-UVC device exhibits a UVC non-compliance (either because itsĭevelopers have interpreted the UVC specification incorrectly, or because Or even been sold, but the harm is done and we need to find a way to cope They should not have been labelled as UVC-compliant To be fair, most UVC devices are buggy,Īnd some of them are so broken that they will not work with the uvcvideoĭriver out of the box. This will only take effect for newly plugged devices. (either globally or selectively for your device).Įcho -1 > /sys/module/usbcore/parameters/autosuspend
Problem, you should update to a v3.6 or newer kernel, or disable autosuspend If you think your system is affected by the Starting at kernel v3.6 the USB core works around the issue by resetting This results in several different symptoms, such as large stream Including most Logitech UVC webcams, can't resume correctly from USB Unfortunately it turns out that many cameras, Save energy (this should not be confused with system suspend, where the UVC devices that are not in use will be suspended after a delay to Starting at kernel v2.6.37 the uvcvideo driver enables USB autosuspend byĭefault. (on a Linux kernel between v2.3.37 and v3.5 inclusive) My camera produces corrupted images, is very slow to start or is generally You can use a panel application such as qv4l2 or a command lineĪpplication such as yavta to control exposure. Your webcam application doesn't offer a way to access those controls, Through the 'Exposure, Auto' and 'Exposure (Absolute)' controls. You can disable auto-exposure and control the exposure time manually
The environment is too dark, the webcam can automatically raise theĮxposure time and thus lower the frame rate. Why does my webcam only produce 15 frames per second while it isīeside the obvious reason of false advertising, the actual frame The frame rate with: mplayer tv:// -tv fps=25 Older MPlayer version had trouble detecting video frame rates forĭigital video devices such as webcams. V4l2: 0 frames successfully processed, 0 frames dropped. V4l2: ioctl set mute failed: Invalid argument When querying devices for their supported frame rate, MPlayerĮxits with the following message in its log: FPS not specified in the header or invalid, use the -fps option. MPlayer exits with 'FPS not specified in the header or invalid'. Attach dmesg.log (and possibly lsusb.log) to the e-mail.
Luvcview are common test tools for UVC webcams, but feel free to try other V4L2Īpplications as well. You should start with trying several applications. Or broken hardware (cameras, USB cables and USB host controllers can be faulty). Failures are usually caused by buggy applications If your webcam is UVC-compatible, it should be supported out of the box in any I have an UVC webcam but it is not working. If there are no such lines, your device is not a UVC device. In this case the Linux UVC driver should recognize your camera when you plug it in. If your device is a UVC device, you should see a number of lines that look like this:
Linux UVC driver & tools – FAQ Linux UVC driver and tools – FAQ