我使用可启动的 USB 驱动器格式化我的整个笔记本电脑（当我的笔记本电脑变得卡顿时我就这么做）。在此之前，我的网络摄像头工作正常，但格式化之后，它就停止工作了，所以我认为这不是硬件问题。我不知道如何调试这个问题，任何帮助都很有帮助！
打开 cheese 后，屏幕一片空白，注意所有按钮都已禁用。我的网络摄像头旁边的手电筒已打开。
输出ls /dev/video*
/dev/video0 /dev/video1
输出lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal
输出lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 005: ID 0cf3:e009 Qualcomm Atheros Communications
Bus 001 Device 004: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 001 Device 003: ID 1bcf:0b09 Sunplus Innovation Technology Inc. SPCA2085 PC Camera
Bus 001 Device 002: ID 046d:c534 Logitech, Inc. Unifying Receiver
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
运行时输出gucview。再次，我的网络摄像头旁边的手电筒亮了。
V4L2_CORE: Unable to find parent usb device.GUVCVIEW: version 2.0.6
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
ALSA lib pcm.c:2642:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2642:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2642:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
ALSA lib pcm_route.c:869:(find_matching_chmap) Found no matching channel map
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
ALSA lib pcm_oss.c:377:(_snd_pcm_oss_open) Unknown field port
ALSA lib pcm_oss.c:377:(_snd_pcm_oss_open) Unknown field port
ALSA lib pcm_usb_stream.c:486:(_snd_pcm_usb_stream_open) Invalid type for card
ALSA lib pcm_usb_stream.c:486:(_snd_pcm_usb_stream_open) Invalid type for card
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
V4L2_CORE: Could not grab image (select timeout): Resource temporarily unavailable
V4L2_CORE: Could not grab image (select timeout): Resource temporarily unavailable
V4L2_CORE: Could not grab image (select timeout): Resource temporarily unavailable
输出cat /etc/modprobe.d/blacklist.conf
# This file lists those modules which we don't want to be loaded by
# alias expansion, usually so some other driver will be loaded for the
# device instead.
# evbug is a debug tool that should be loaded explicitly
blacklist evbug
# these drivers are very simple, the HID drivers are usually preferred
blacklist usbmouse
blacklist usbkbd
# replaced by e100
blacklist eepro100
# replaced by tulip
blacklist de4x5
# causes no end of confusion by creating unexpected network interfaces
blacklist eth1394
# snd_intel8x0m can interfere with snd_intel8x0, doesn't seem to support much
# hardware on its own (Ubuntu bug #2011, #6810)
blacklist snd_intel8x0m
# Conflicts with dvb driver (which is better for handling this device)
blacklist snd_aw2
# replaced by p54pci
blacklist prism54
# replaced by b43 and ssb.
blacklist bcm43xx
# most apps now use garmin usb driver directly (Ubuntu: #114565)
blacklist garmin_gps
# replaced by asus-laptop (Ubuntu: #184721)
blacklist asus_acpi
# low-quality, just noise when being used for sound playback, causes
# hangs at desktop session start (Ubuntu: #246969)
blacklist snd_pcsp
# ugly and loud noise, getting on everyone's nerves; this should be done by a
# nice pulseaudio bing (Ubuntu: #77010)
blacklist pcspkr
# EDAC driver for amd76x clashes with the agp driver preventing the aperture
# from being initialised (Ubuntu: #297750). Blacklist so that the driver
# continues to build and is installable for the few cases where its
# really needed.
blacklist amd76x_edac
答案1
许多设备访问问题可以通过组成员身份变更来解决。
做ls -l /dev/video*
具体来说，如果ls -l 显示组权限（第二个“ rwx”三元组）为“ rw”（例如“ -rw-rw----”），那么将自己添加到拥有该设备的组将授予rw访问权限。
就是这样：
device="/dev/video0"
sudo adduser $USER $(stat -c "%G" $device)
rw这允许您成为可以使用该设备的群组的成员，但还有一步。
要使所有进程成为新组的成员，请注销并登录。组成员资格是按时设置的login。
答案2
在 GRUB 中的 quiet splash 后添加 nomodeset 可以暂时解决这个问题（回顾性答案）。
保存文件并使用 update-grub 使更改永久生效。
另外，关闭安全启动，因为它可能会阻止在启动时加载必要的驱动程序。
这是一个帮助您禁用安全启动的链接
答案3
我在 ubuntu - 20.04 上使用 cheese 时遇到了同样的问题。摄像头闪烁，cheese 中完全是黑屏。尝试以下操作：虚拟机设置 -> Usb 控制器 -> 将连接下的 Usb 兼容性更改为 USB 3.1/1.1。这两种方法都对我有用。最初，它默认设置为 USB 2.0
答案4
另一件需要检查的傻事是，打开 cheese 后，进入“首选项”，检查“亮度”、“对比度”、“饱和度”和“色相”的滑块。
若位置不对，请将滑块移至中间的参考位置。