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问题[webcam](ubuntu)

Martin Hope
Craig Howard
Asked: 2023-10-21 07:40:21 +0800 CST
  • 6

我有一个 nexigo 高清网络摄像头，可以在我的工作笔记本电脑（运行 Ubuntu）上运行，但在我的台式机（也运行 Ubuntu）上失败。我确信我的桌面上有一些配置错误，但我不知道下一步要检查什么。

我尝试过各种网络浏览器、cheese、qv4l2、obs-studio 和 gst-launch-1.0。这是带有 USB 网络摄像头的标准台式机，因此无需按特殊按键即可启用摄像头，也没有物理开关。这只是在测试之间在我的笔记本电脑和台式机之间拔出/插入。这不太可能相关，但我的台式机使用的是 AMD 显卡。这是在裸机上，没有虚拟化、docker、snap、flatpak 等。至少，我看不到。

以下全部来自我的桌面，网络摄像头无法正常工作。我在视频组：

└──> ls -l /dev/video*
crw-rw----+ 1 root video 81, 0 Oct 20 16:10 /dev/video0
crw-rw----+ 1 root video 81, 1 Oct 20 16:10 /dev/video1
└──> groups | grep -o video
video

发现设备：

└──> v4l2-ctl --list-devices
NexiGo N60 FHD Webcam: NexiGo N (usb-0000:0c:00.3-3.1.2):
        /dev/video0
        /dev/video1
        /dev/media0

这是一个相对标准的uvcvideo设备：

└──> v4l2-dbg -D -d /dev/video0   
Driver info:
        Driver name   : uvcvideo
        Card type     : NexiGo N60 FHD Webcam: NexiGo N
        Bus info      : usb-0000:0c:00.3-3.1.2
        Driver version: 6.2.16
        Capabilities  : 0x84A00001
                Video Capture
                Streaming
                Extended Pix Format
                Device Capabilities

但我无法分配缓冲区。我认为问题与其他程序相同，但我不能总是得到好的日志。

└──> GST_DEBUG="v4l2*:3" gst-launch-1.0 v4l2src device=/dev/video0 ! videoscale ! videoconvert ! autovideosink
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
0:00:00.079505628 31240 0x564e88fc6800 ERROR         v4l2bufferpool gstv4l2bufferpool.c:706:gst_v4l2_buffer_pool_streamon:<v4l2src0:pool0:src> error with STREAMON 5 (Input/output error)
0:00:00.079591570 31240 0x564e88fc6800 WARN                 v4l2src gstv4l2src.c:759:gst_v4l2src_decide_allocation:<v4l2src0> error: Failed to allocate required memory.
0:00:00.079597662 31240 0x564e88fc6800 WARN                 v4l2src gstv4l2src.c:759:gst_v4l2src_decide_allocation:<v4l2src0> error: Buffer pool activation failed
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Failed to allocate required memory.
Additional debug info:
../sys/v4l2/gstv4l2src.c(759): gst_v4l2src_decide_allocation (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
Buffer pool activation failed
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Internal data stream error.
Additional debug info:
../libs/gst/base/gstbasesrc.c(3127): gst_base_src_loop (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
streaming stopped, reason not-negotiated (-4)
Execution ended after 0:00:00.059204336
Setting pipeline to NULL ...
Freeing pipeline ...

看看上面的 strace，我正在EIO从ioctlfor得到VIDIOC_STREAMON。

34265 ioctl(7, VIDIOC_REQBUFS, {type=V4L2_BUF_TYPE_VIDEO_CAPTURE, memory=V4L2_MEMORY_MMAP, count=2 => 2}) = 0
34265 ioctl(7, VIDIOC_QUERYBUF, {type=V4L2_BUF_TYPE_VIDEO_CAPTURE, index=0, memory=V4L2_MEMORY_MMAP, m.offset=0, length=1843200, bytesused=0, flags=V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC|V4L2_BUF_FLAG_TSTAMP_SRC_SOE, ...}) = 0
34265 ioctl(7, VIDIOC_QUERYBUF, {type=V4L2_BUF_TYPE_VIDEO_CAPTURE, index=1, memory=V4L2_MEMORY_MMAP, m.offset=0x1c2000, length=1843200, bytesused=0, flags=V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC|V4L2_BUF_FLAG_TSTAMP_SRC_SOE, ...}) = 0
34265 ioctl(7, VIDIOC_EXPBUF, 0x7f0445e3da10) = 0
34265 futex(0x7f04486e10a8, FUTEX_WAKE_PRIVATE, 2147483647) = 0
34265 ioctl(7, VIDIOC_QBUF, {type=V4L2_BUF_TYPE_VIDEO_CAPTURE, index=0, memory=V4L2_MEMORY_MMAP, m.offset=0, length=1843200, bytesused=0, flags=V4L2_BUF_FLAG_MAPPED|V4L2_BUF_FLAG_QUEUED|V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC|V4L2_BUF_FLAG_TSTAMP_SRC_SOE, ...}) = 0
34265 futex(0x7f043800c628, FUTEX_WAKE_PRIVATE, 1) = 0
34265 ioctl(7, VIDIOC_EXPBUF, 0x7f0445e3da10) = 0
34265 ioctl(7, VIDIOC_QBUF, {type=V4L2_BUF_TYPE_VIDEO_CAPTURE, index=1, memory=V4L2_MEMORY_MMAP, m.offset=0x1c2000, length=1843200, bytesused=0, flags=V4L2_BUF_FLAG_MAPPED|V4L2_BUF_FLAG_QUEUED|V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC|V4L2_BUF_FLAG_TSTAMP_SRC_SOE, ...}) = 0
34265 futex(0x7f043800c628, FUTEX_WAKE_PRIVATE, 1) = 0
34265 ioctl(13, VIDIOC_STREAMON, [V4L2_BUF_TYPE_VIDEO_CAPTURE]) = -1 EIO (Input/output error)

这就是我陷入困境的地方。接下来我应该看什么？

谢谢。

webcam
Martin Hope
con
Asked: 2023-01-01 14:28:45 +0800 CST
  • 5

我的 Ubuntu HP 笔记本电脑找不到它的摄像头，所以我无法使用视频。

相机显示“未找到设备”没有帮助。

从那个问题，

sudo lshw -class video

有输出

  *-display                 
       description: VGA compatible controller
       product: CometLake-U GT2 [UHD Graphics]
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       logical name: /dev/fb0
       version: 02
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress msi pm vga_controller bus_master cap_list rom fb
       configuration: depth=32 driver=i915 latency=0 resolution=1920,1080
       resources: irq:142 memory:b2000000-b2ffffff memory:c0000000-cfffffff ioport:5000(size=64) memory:c0000-dffff
  *-display
       description: 3D controller
       product: GP108M [GeForce MX250]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list rom
       configuration: driver=nouveau latency=0
       resources: irq:141 memory:b3000000-b3ffffff memory:a0000000-afffffff memory:b0000000-b1ffffff ioport:4000(size=128)

我也可以

lsusb -v | grep Camera

正如集成相机所建议的那样

给出错误：

Couldn't open device, some information will be missing
Couldn't open device, some information will be missing
Couldn't open device, some information will be missing
Couldn't open device, some information will be missing
Couldn't open device, some information will be missing
Couldn't open device, some information will be missing

的输出lsusb是巨大的，为了简洁起见，我不想在这里放那么多信息。

当我启动时cheese，我在终端上收到以下警告：

** Message: 16:26:26.963: cheese-application.vala:222: Error during camera setup: No device found


(cheese:19569): cheese-CRITICAL **: 16:26:26.972: cheese_camera_device_get_name: assertion 'CHEESE_IS_CAMERA_DEVICE (device)' failed

(cheese:19569): GLib-CRITICAL **: 16:26:26.972: g_variant_new_string: assertion 'string != NULL' failed

(cheese:19569): GLib-CRITICAL **: 16:26:26.972: g_variant_ref_sink: assertion 'value != NULL' failed

(cheese:19569): GLib-GIO-CRITICAL **: 16:26:26.972: g_settings_schema_key_type_check: assertion 'value != NULL' failed

(cheese:19569): GLib-CRITICAL **: 16:26:26.972: g_variant_get_type_string: assertion 'value != NULL' failed

(cheese:19569): GLib-GIO-CRITICAL **: 16:26:26.972: g_settings_set_value: key 'camera' in 'org.gnome.Cheese' expects type 's', but a GVariant of type '(null)' was given

(cheese:19569): GLib-CRITICAL **: 16:26:26.972: g_variant_unref: assertion 'value != NULL' failed

** (cheese:19569): CRITICAL **: 16:26:26.972: cheese_preferences_dialog_setup_resolutions_for_device: assertion 'device != NULL' failed

关于屏幕显示以下系统信息：

关于

还lspci列出

00:00.0 Host bridge: Intel Corporation Comet Lake-U v1 4c Host Bridge/DRAM Controller (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation CometLake-U GT2 [UHD Graphics] (rev 02)
00:04.0 Signal processing controller: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem (rev 0c)
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
00:12.0 Signal processing controller: Intel Corporation Comet Lake Thermal Subsytem
00:14.0 USB controller: Intel Corporation Comet Lake PCH-LP USB 3.1 xHCI Host Controller
00:14.2 RAM memory: Intel Corporation Comet Lake PCH-LP Shared SRAM
00:14.3 Network controller: Intel Corporation Comet Lake PCH-LP CNVi WiFi
00:14.5 SD Host controller: Intel Corporation Comet Lake PCH-LP SCS3
00:15.0 Serial bus controller: Intel Corporation Serial IO I2C Host Controller
00:15.1 Serial bus controller: Intel Corporation Comet Lake Serial IO I2C Host Controller
00:16.0 Communication controller: Intel Corporation Comet Lake Management Engine Interface
00:17.0 RAID bus controller: Intel Corporation 82801 Mobile SATA Controller [RAID mode]
00:1c.0 PCI bridge: Intel Corporation Comet Lake PCI Express Root Port #1 (rev f0)
00:1c.4 PCI bridge: Intel Corporation Comet Lake PCI Express Root Port #5 (rev f0)
00:1d.0 PCI bridge: Intel Corporation Comet Lake PCI Express Root Port #9 (rev f0)
00:1d.4 PCI bridge: Intel Corporation Comet Lake PCI Express Root Port #13 (rev f0)
00:1f.0 ISA bridge: Intel Corporation Comet Lake PCH-LP LPC Premium Controller/eSPI Controller
00:1f.3 Multimedia audio controller: Intel Corporation Comet Lake PCH-LP cAVS
00:1f.4 SMBus: Intel Corporation Comet Lake PCH-LP SMBus Host Controller
00:1f.5 Serial bus controller: Intel Corporation Comet Lake SPI (flash) Controller
02:00.0 3D controller: NVIDIA Corporation GP108M [GeForce MX250] (rev a1)
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
04:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller 980

我怎样才能让我的相机/网络摄像头重新工作？

webcam
Martin Hope
Vitor_figm
Asked: 2022-01-05 17:45:42 +0800 CST
  • 2

除了我在 linux 上使用 irium 网络摄像头时遇到的其他问题，当我们关闭 irium 网络摄像头并尝试再次打开它时，我们会收到以下消息：
在此处输入图像描述

运行此命令不会使应用程序工作。让 iriun 再次工作的唯一方法是重新启动计算机。

当我直接从终端运行它时iriunwebcam，终端不会显示任何错误消息或任何消息，只是打开应用程序 GUI。

有谁知道我该如何解决这个问题？

编辑

我正在使用 Ubuntu 21.10，我记得在使用 Pop OS 20.xx 时遇到了同样的问题（不记得其他数字了）。

webcam
Martin Hope
fikr4n
Asked: 2021-08-14 03:33:10 +0800 CST
  • 0

在zoom-client（从快照中）我可以选择是否使用高清视频，结果当我关闭缩放并打开奶酪时，这个设置仍然存在。这让我觉得这个设置是全局的，而不是缩放特定的。不幸的是 Cheese 没有这个设置，所以我需要打开 Zoom 来改变这个设置。

截屏

我的问题是，我可以通过终端命令行或设置 GUI（例如 gnome 设置）在不打开 Zoom 的情况下更改网络摄像头分辨率吗？

webcam
Martin Hope
TRiG
Asked: 2021-04-21 14:56:21 +0800 CST
  • 5

我发现一些指南说这曾经很复杂，但现在很简单

sudo apt install obs-studio && sudo apt install v4l2loopback-dkms

这确实给了我 OBS Studio 上的“启动虚拟相机”按钮。当我单击它时，系统会提示我输入密码。就是这样。没有其他事情发生。该按钮仍然显示“启动虚拟摄像头”（它应该更改为“停止虚拟摄像头”）。Firefox、Zoom 或 Cheese 没有检测到虚拟摄像头。

难道我做错了什么？

webcam
Martin Hope
IRF
Asked: 2021-02-13 05:00:36 +0800 CST
  • 0

我已经为学校目的安装了缩放，它可以检测到摄像头和麦克风，当我在配置中测试它们时它们可以工作，但是当我加入会议时它们突然停止工作。他们仍然被认可，但他们不工作。

有什么解决办法吗？

谢谢

webcam
Martin Hope
ubuntuuser
Asked: 2021-02-09 02:49:02 +0800 CST
  • 2

我的网络摄像头闪烁。我尝试更改 GUVCView 和 v4l2ucp 中的设置（请参见屏幕截图，您可以看到灰色和白色条纹，它们一直在变化）但这无济于事，电源线频率为 60 Hz 和 50 Hz。摄像头是 AUKEY Webcam 1080P Full HD，我有 ubuntu 18.04。我必须有人造光，因为我的办公室没有窗户。 在此处输入图像描述

webcam
Martin Hope
John Miller
Asked: 2021-01-31 05:38:49 +0800 CST
  • 4

我需要以 1080p (1920x1080) 的速度以 60fps 使用我的 Logitech Streamcam 网络摄像头，但它既不能在 OBS Studio 中工作，也不能在 guvcview 中工作，如果我想将输出保存为视频文件，ffmpeg 会冻结 :( 提前感谢你的帮助。

** 2 月 3 日更新 (2)：新的 dmesg 信息/数据

OBS工作室

以下步骤没有问题，但如果我更改为 1080p 和/或 60fps，ffmpeg 会冻结。

# sudo modprobe v4l2loopback
# ffmpeg -f v4l2 -input_format mjpeg -framerate 30 -s 1280x720 -i /dev/video0 -pix_fmt yuyv422 -f v4l2 /dev/video2

ffmpeg => 视频文件 720p@30

以下步骤没有问题，但如果我更改为 1080p 和/或 60fps，ffmpeg 会冻结。

# ffmpeg -f v4l2 -input_format mjpeg -framerate 30 -s 1280x720 -i /dev/video0 -pix_fmt yuvj422p video-test-output.mp4

ffmpeg => 视频文件 1080p@30

通过以下步骤，ffmpeg 冻结

# ffmpeg -f v4l2 -input_format mjpeg -framerate 30 -s 1920x1080 -i /dev/video0 -pix_fmt yuvj422p video-test-output.mp4
ffmpeg version 4.1.4-1build2 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.2.1-4ubuntu1)
  configuration: --prefix=/usr --extra-version=1build2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
[video4linux2,v4l2 @ 0x55cf92dc5ac0] Could not find codec parameters for stream 0 (Video: mjpeg, none(bt470bg/unknown/unknown), 1920x1080): unspecified pixel format
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: mjpeg, none(bt470bg/unknown/unknown), 1920x1080, 30 fps, 30 tbr, 1000k tbn, 1000k tbc
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg (native) -> h264 (libx264))
Press [q] to stop, [?] for help
Cannot determine format of input stream 0:0 after EOF
Error marking filters as finished
Exiting normally, received signal 2.

测试 (1) 我尝试将网络摄像头设置更改为 1080p，但没有成功。

# v4l2-ctl --device /dev/video0 --set-fmt-video=width=1920,height=1080,pixelformat=MJPG

可能有用的附加信息/数据

# uname -r
5.3.0-64-generic

# dmesg
[    5.120382] usb 2-8: current rate 16000 is different from the runtime rate 48000
[    5.121990] snd_hda_codec_realtek hdaudioC2D0: autoconfig for ALC1220: line_outs=3 (0x14/0x15/0x16/0x0/0x0) type:line
[    5.121992] snd_hda_codec_realtek hdaudioC2D0:    speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
[    5.121993] snd_hda_codec_realtek hdaudioC2D0:    hp_outs=1 (0x1b/0x0/0x0/0x0/0x0)
[    5.121994] snd_hda_codec_realtek hdaudioC2D0:    mono: mono_out=0x0
[    5.121995] snd_hda_codec_realtek hdaudioC2D0:    dig-out=0x1e/0x0
[    5.121995] snd_hda_codec_realtek hdaudioC2D0:    inputs:
[    5.121997] snd_hda_codec_realtek hdaudioC2D0:      Front Mic=0x19
[    5.121998] snd_hda_codec_realtek hdaudioC2D0:      Rear Mic=0x18
[    5.121998] snd_hda_codec_realtek hdaudioC2D0:      Line=0x1a
[    5.141136] uvcvideo: Found UVC 1.00 device Logitech StreamCam (046d:0893)
[    5.157490] uvcvideo 2-8:1.0: Entity type for entity Processing 3 was not initialized!
[    5.157493] uvcvideo 2-8:1.0: Entity type for entity Extension 14 was not initialized!
[    5.157495] uvcvideo 2-8:1.0: Entity type for entity Extension 6 was not initialized!
[    5.157496] uvcvideo 2-8:1.0: Entity type for entity Extension 8 was not initialized!
[    5.157498] uvcvideo 2-8:1.0: Entity type for entity Extension 9 was not initialized!
[    5.157499] uvcvideo 2-8:1.0: Entity type for entity Extension 10 was not initialized!
[    5.157500] uvcvideo 2-8:1.0: Entity type for entity Extension 11 was not initialized!
[    5.157502] uvcvideo 2-8:1.0: Entity type for entity Camera 1 was not initialized!
[    5.157583] input: Logitech StreamCam as /devices/pci0000:00/0000:00:01.3/0000:02:00.0/usb2/2-8/2-8:1.0/input/input32
[    5.157671] usbcore: registered new interface driver uvcvideo
[    5.157672] USB Video Class driver (1.1.1)

2021 年 2 月 3 日：我在计算机完全加载后插入网络摄像头，这是 dmesg 信息：

# dmesg
[  553.490310] usb 2-7: new SuperSpeed Gen 1 USB device number 2 using xhci_hcd
[  553.517111] usb 2-7: New USB device found, idVendor=046d, idProduct=0893, bcdDevice= 3.17
[  553.517114] usb 2-7: New USB device strings: Mfr=0, Product=2, SerialNumber=3
[  553.517116] usb 2-7: Product: Logitech StreamCam
[  553.517118] usb 2-7: SerialNumber: XR6W1K92
[  553.541903] usb 2-7: current rate 16000 is different from the runtime rate 24000
[  553.548111] usb 2-7: current rate 16000 is different from the runtime rate 32000
[  553.554401] usb 2-7: current rate 16000 is different from the runtime rate 48000
[  553.573341] hid-generic 0003:046D:0893.0008: hiddev5,hidraw7: USB HID v1.11 Device [Logitech StreamCam] on usb-0000:02:00.0-7/input5
[  553.629854] videodev: Linux video capture interface: v2.00
[  553.642019] uvcvideo: Found UVC 1.00 device Logitech StreamCam (046d:0893)
[  553.657973] uvcvideo 2-7:1.0: Entity type for entity Processing 3 was not initialized!
[  553.657975] uvcvideo 2-7:1.0: Entity type for entity Extension 14 was not initialized!
[  553.657977] uvcvideo 2-7:1.0: Entity type for entity Extension 6 was not initialized!
[  553.657978] uvcvideo 2-7:1.0: Entity type for entity Extension 8 was not initialized!
[  553.657979] uvcvideo 2-7:1.0: Entity type for entity Extension 9 was not initialized!
[  553.657981] uvcvideo 2-7:1.0: Entity type for entity Extension 10 was not initialized!
[  553.657982] uvcvideo 2-7:1.0: Entity type for entity Extension 11 was not initialized!
[  553.657983] uvcvideo 2-7:1.0: Entity type for entity Camera 1 was not initialized!
[  553.658054] input: Logitech StreamCam as /devices/pci0000:00/0000:00:01.3/0000:02:00.0/usb2/2-7/2-7:1.0/input/input32
[  553.658127] usbcore: registered new interface driver uvcvideo
[  553.658128] USB Video Class driver (1.1.1)
[  553.724131] usb 2-7: current rate 16000 is different from the runtime rate 48000
[  553.737390] usb 2-7: current rate 16000 is different from the runtime rate 48000
[  553.755142] usb 2-7: current rate 16000 is different from the runtime rate 48000

# lsusb
Bus 002 Device 002: ID 046d:0893 Logitech, Inc. Logitech StreamCam

# v4l2-ctl -V
Format Video Capture:
    Width/Height      : 1280/720
    Pixel Format      : 'MJPG' (Motion-JPEG)
    Field             : None
    Bytes per Line    : 0
    Size Image        : 1843200
    Colorspace        : sRGB
    Transfer Function : Default (maps to sRGB)
    YCbCr/HSV Encoding: Default (maps to ITU-R 601)
    Quantization      : Default (maps to Full Range)
    Flags             :

# v4l2-ctl --list-devices
Logitech StreamCam (usb-0000:02:00.0-8):
    /dev/video0
    /dev/video1

# v4l2-ctl --list-formats-ext -d /dev/video0
ioctl: VIDIOC_ENUM_FMT
    Type: Video Capture

    [0]: 'YUYV' (YUYV 4:2:2)
        Size: Discrete 640x480
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 176x144
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 320x240
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 424x240
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 640x360
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 848x480
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 960x540
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1280x720
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1600x896
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1920x1080
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 2304x1296
            Interval: Discrete 0.200s (5.000 fps)
    [1]: 'MJPG' (Motion-JPEG, compressed)
        Size: Discrete 640x480
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 176x144
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 320x240
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 424x240
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 640x360
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 848x480
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 960x540
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1280x720
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1600x896
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1920x1080
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
    [2]: 'NV12' (Y/CbCr 4:2:0)
        Size: Discrete 640x480
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 640x360
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1280x720
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1920x1080
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
webcam