Ich verwende seit mehreren Jahren eine Logitech C270-Webcam ohne Probleme auf meinem System mit Ubuntu 20.10. Seit gestern gibt die Webcam jedoch kein Video mehr in Zoom und allen anderen Videoaufnahmeprogrammen aus. Das Licht an der Kamera leuchtet auf und zeigt an, dass sie ein Video aufnimmt. dmesg und lsusb zeigen an, dass die Kamera erkannt wurde, aber es werden keine Fehler angezeigt. Ich wüsste nichts, was ich hätte tun können, was dies verursacht haben könnte, außer Kernel-Updates zu installieren.
Ich habe versucht, ohne Änderungen zu einer älteren Kernel-Version, linux-image-5.8.0-55-generic, zurückzukehren (die neueste, die ich installiert habe, ist linux-image-5.8.0-59-generic).
Das einzige Feedback, das ich finden konnte, stammt von der Ausführung von guvcview. Hier ist die Ausgabe:
GUVCVIEW: version 2.0.6
GUVCVIEW: couldn't open /home/etrochim/.config/guvcview2/video0 for read: No such file or directory
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: No such file or directory
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_dsnoop.c:642:(snd_pcm_dsnoop_open) unable to open slave
ALSA lib pcm_dmix.c:1090:(snd_pcm_dmix_open) unable to open slave
ALSA lib pcm.c:2660:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2660:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2660:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
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
ALSA lib pcm_dmix.c:1090:(snd_pcm_dmix_open) unable to open slave
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
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
V4L2_CORE: Could not grab image (select timeout): Resource temporarily unavailable
GUVCVIEW: (status) saving video to /home/etrochim/my_video-1.mkv
ENCODER: add stream 0 to stream list
ENCODER: add stream 1 to stream list
ENCODER: (matroska) add seekhead entry 0 (max 10)
ENCODER: (matroska) add seekhead entry 1 (max 10)
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
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
V4L2_CORE: Could not grab image (select timeout): Resource temporarily unavailable
Irgendwelche Ideen, was falsch sein könnte?
Antwort1
Nachdem ich die Frage gepostet hatte, habe ich das Problem natürlich behoben. Die Webcam ist über die USB-Anschlüsse an meinem Monitor mit meinem Desktop verbunden. Ich hatte ursprünglich versucht, das USB-Kabel von meinem Monitor zum Desktop zu trennen und wieder anzuschließen, was nicht funktionierte. Aber das Trennen und erneute Anschließen der Webcam an meinen Monitor hat funktioniert. Ich habe keine Ahnung, warum, aber zumindest bin ich wieder im Geschäft.