背景信息:
我使用 RPi B+ (Raspbian) 构建了一个智能门解决方案，它使用三个传感器(PIR、陀螺仪 [I2C] 和超声波)。根据 Python 脚本管理的传感器状态，我开始使用 raspivid 命令录制视频和/或在蓝牙扬声器上播放声音。我还有一个连接到 RPi 的 USB WIFI 加密狗。
这就是我在 .sh 文件中调用 Pi NoIR 相机的方式:
raspivid -w 800 -h 600 -t 15000 -o file.h264 -n -rot 270
问题描述:
摄像头可以正常工作一段时间(我无法准确说明多长时间 [可能是 2 小时]，也无法确定是什么触发了问题)，但随后就停止工作了。有趣的是我没有收到任何错误消息。
我做了什么来确定根本原因:
我尝试手动终止子进程 (Raspivid)，但根本行不通。如果我终止父进程(.sh 文件)，那么我的子进程将分配给 PID 1 (init.d)。
我尝试在新终端窗口中录制新视频，但新进程也挂起。
重启树莓派也没用。它说它正在重新启动，但实际上并没有(即使使用 -f 选项也没有)。
我安装了一个新的 Pi 相机，确保它不是硬件或色带问题。
相机有足够的可用内存。
Pi 电量充足(红灯常亮)
-v 不返回错误
我已经安装了 V4L2-CTL，但我遇到了同样的问题
我怎样才能修复它？ 谢谢!
** 编辑 **
dmesg:
[ 90.555578] ------------[ cut here ]------------
[ 90.555698] WARNING: CPU: 0 PID: 3593 at drivers/media/v4l2-core/videobuf2-core.c:2135 __vb2_queue_cancel+0xf4/0x160 [videobuf2_core]()
[ 90.555715] Modules linked in: evdev uinput rfcomm bnep bcm2835_v4l2 videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media snd_bcm2835 snd_pcm snd_seq snd_seq_device snd_timer snd spi_bcm2708 i2c_bcm2708 i2c_dev ecb btusb 8192cu bluetooth rfkill uio_pdrv_genirq uio
[ 90.555843] CPU: 0 PID: 3593 Comm: v4l2-ctl Not tainted 3.18.7+ #755
[ 90.555915] [<c00151fc>] (unwind_backtrace) from [<c0012710>] (show_stack+0x20/0x24)
[ 90.556012] [<c0012710>] (show_stack) from [<c0555b30>] (dump_stack+0x20/0x28)
[ 90.556053] [<c0555b30>] (dump_stack) from [<c0022ef4>] (warn_slowpath_common+0x7c/0x9c)
[ 90.556083] [<c0022ef4>] (warn_slowpath_common) from [<c0022fd0>] (warn_slowpath_null+0x2c/0x34)
[ 90.556143] [<c0022fd0>] (warn_slowpath_null) from [<bf263a1c>] (__vb2_queue_cancel+0xf4/0x160 [videobuf2_core])
[ 90.556252] [<bf263a1c>] (__vb2_queue_cancel [videobuf2_core]) from [<bf265548>] (vb2_internal_streamoff+0x40/0xdc [videobuf2_core])
[ 90.556361] [<bf265548>] (vb2_internal_streamoff [videobuf2_core]) from [<bf2656d8>] (vb2_streamoff+0x3c/0x60 [videobuf2_core])
[ 90.556436] [<bf2656d8>] (vb2_streamoff [videobuf2_core]) from [<bf26574c>] (vb2_ioctl_streamoff+0x50/0x54 [videobuf2_core])
[ 90.556669] [<bf26574c>] (vb2_ioctl_streamoff [videobuf2_core]) from [<bf228658>] (v4l_streamoff+0x28/0x2c [videodev])
[ 90.556938] [<bf228658>] (v4l_streamoff [videodev]) from [<bf22baf4>] (__video_do_ioctl+0x254/0x2e8 [videodev])
[ 90.557182] [<bf22baf4>] (__video_do_ioctl [videodev]) from [<bf22b49c>] (video_usercopy+0x180/0x560 [videodev])
[ 90.557414] [<bf22b49c>] (video_usercopy [videodev]) from [<bf22b898>] (video_ioctl2+0x1c/0x24 [videodev])
[ 90.557616] [<bf22b898>] (video_ioctl2 [videodev]) from [<bf2266b0>] (v4l2_ioctl+0x11c/0x14c [videodev])
[ 90.557791] [<bf2266b0>] (v4l2_ioctl [videodev]) from [<c014c478>] (do_vfs_ioctl+0x3f0/0x5d4)
[ 90.557872] [<c014c478>] (do_vfs_ioctl) from [<c014c6a0>] (SyS_ioctl+0x44/0x6c)
[ 90.557917] [<c014c6a0>] (SyS_ioctl) from [<c000e8c0>] (ret_fast_syscall+0x0/0x48)
[ 90.557936] ---[ end trace 28c9150399e29093 ]---
[ 3123.544118] ------------[ cut here ]------------
[ 3123.544235] WARNING: CPU: 0 PID: 28629 at drivers/media/v4l2-core/videobuf2-core.c:2135 __vb2_queue_cancel+0xf4/0x160 [videobuf2_core]()
[ 3123.544251] Modules linked in: evdev uinput rfcomm bnep bcm2835_v4l2 videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media snd_bcm2835 snd_pcm snd_seq snd_seq_device snd_timer snd spi_bcm2708 i2c_bcm2708 i2c_dev ecb btusb 8192cu bluetooth rfkill uio_pdrv_genirq uio
[ 3123.544404] CPU: 0 PID: 28629 Comm: v4l2-ctl Tainted: G W 3.18.7+ #755
[ 3123.544475] [<c00151fc>] (unwind_backtrace) from [<c0012710>] (show_stack+0x20/0x24)
[ 3123.544570] [<c0012710>] (show_stack) from [<c0555b30>] (dump_stack+0x20/0x28)
[ 3123.544676] [<c0555b30>] (dump_stack) from [<c0022ef4>] (warn_slowpath_common+0x7c/0x9c)
[ 3123.545092] [<c0022ef4>] (warn_slowpath_common) from [<c0022fd0>] (warn_slowpath_null+0x2c/0x34)
[ 3123.545178] [<c0022fd0>] (warn_slowpath_null) from [<bf263a1c>] (__vb2_queue_cancel+0xf4/0x160 [videobuf2_core])
[ 3123.545253] [<bf263a1c>] (__vb2_queue_cancel [videobuf2_core]) from [<bf265548>] (vb2_internal_streamoff+0x40/0xdc [videobuf2_core])
[ 3123.545316] [<bf265548>] (vb2_internal_streamoff [videobuf2_core]) from [<bf2656d8>] (vb2_streamoff+0x3c/0x60 [videobuf2_core])
[ 3123.545377] [<bf2656d8>] (vb2_streamoff [videobuf2_core]) from [<bf26574c>] (vb2_ioctl_streamoff+0x50/0x54 [videobuf2_core])
[ 3123.545562] [<bf26574c>] (vb2_ioctl_streamoff [videobuf2_core]) from [<bf228658>] (v4l_streamoff+0x28/0x2c [videodev])
[ 3123.545803] [<bf228658>] (v4l_streamoff [videodev]) from [<bf22baf4>] (__video_do_ioctl+0x254/0x2e8 [videodev])
[ 3123.546060] [<bf22baf4>] (__video_do_ioctl [videodev]) from [<bf22b49c>] (video_usercopy+0x180/0x560 [videodev])
[ 3123.546309] [<bf22b49c>] (video_usercopy [videodev]) from [<bf22b898>] (video_ioctl2+0x1c/0x24 [videodev])
[ 3123.546483] [<bf22b898>] (video_ioctl2 [videodev]) from [<bf2266b0>] (v4l2_ioctl+0x11c/0x14c [videodev])
[ 3123.546595] [<bf2266b0>] (v4l2_ioctl [videodev]) from [<c014c478>] (do_vfs_ioctl+0x3f0/0x5d4)
[ 3123.546676] [<c014c478>] (do_vfs_ioctl) from [<c014c6a0>] (SyS_ioctl+0x44/0x6c)
[ 3123.546717] [<c014c6a0>] (SyS_ioctl) from [<c000e8c0>] (ret_fast_syscall+0x0/0x48)
[ 3123.546737] ---[ end trace 28c9150399e29094 ]---
[34462.831249] bcm2835_v4l2: error 0 waiting for sync completion
[34465.833783] bcm2835_v4l2: error 0 waiting for sync completion
[34465.833853] bcm2835_v4l2: failed disconnecting src port
[34468.833772] bcm2835_v4l2: error 0 waiting for sync completion
[34468.833818] bcm2835-v4l2: Failed to disable encode component -62
[34471.834219] bcm2835_v4l2: error 0 waiting for sync completion
[34471.834395] bcm2835-v4l2: vidioc_s_fmt_vid_cap: failed to setup mmal components: -62
[34474.873813] bcm2835_v4l2: error 0 waiting for sync completion
[34474.890435] bcm2835-v4l2: queue_setup: capture port not configured
[34495.914162] bcm2835_v4l2: error 0 waiting for sync completion
[34498.916190] bcm2835_v4l2: error 0 waiting for sync completion
[34498.916290] bcm2835-v4l2: vidioc_s_fmt_vid_cap: failed to setup mmal components: -62
[34502.064159] bcm2835_v4l2: error 0 waiting for sync completion
[34502.070076] bcm2835-v4l2: queue_setup: capture port not configured
[36016.330148] bcm2835_v4l2: error 0 waiting for sync completion
[36019.339279] bcm2835_v4l2: error 0 waiting for sync completion
[36019.339327] bcm2835-v4l2: vidioc_s_fmt_vid_cap: failed to setup mmal components: -62
[36022.430218] bcm2835_v4l2: error 0 waiting for sync completion
[36022.441684] bcm2835-v4l2: queue_setup: capture port not configured
系统日志:
Feb 20 05:35:02 raspberrypi kernel: [34462.831249] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 05:35:05 raspberrypi kernel: [34465.833783] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 05:35:05 raspberrypi kernel: [34465.833853] bcm2835_v4l2: failed disconnecting src port
Feb 20 05:35:08 raspberrypi kernel: [34468.833772] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 05:35:08 raspberrypi kernel: [34468.833818] bcm2835-v4l2: Failed to disable encode component -62
Feb 20 05:35:11 raspberrypi kernel: [34471.834219] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 05:35:11 raspberrypi kernel: [34471.834395] bcm2835-v4l2: vidioc_s_fmt_vid_cap: failed to setup mmal components: -62
Feb 20 05:35:14 raspberrypi kernel: [34474.873813] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 05:35:14 raspberrypi kernel: [34474.890435] bcm2835-v4l2: queue_setup: capture port not configured
Feb 20 05:35:35 raspberrypi kernel: [34495.914162] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 05:35:38 raspberrypi kernel: [34498.916190] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 05:35:38 raspberrypi kernel: [34498.916290] bcm2835-v4l2: vidioc_s_fmt_vid_cap: failed to setup mmal components: -62
Feb 20 05:35:41 raspberrypi kernel: [34502.064159] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 05:35:41 raspberrypi kernel: [34502.070076] bcm2835-v4l2: queue_setup: capture port not configured
Feb 20 06:00:55 raspberrypi kernel: [36016.330148] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 06:00:58 raspberrypi kernel: [36019.339279] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 06:00:58 raspberrypi kernel: [36019.339327] bcm2835-v4l2: vidioc_s_fmt_vid_cap: failed to setup mmal components: -62
Feb 20 06:01:01 raspberrypi kernel: [36022.430218] bcm2835_v4l2: error 0 waiting for sync completion
Feb 20 06:01:01 raspberrypi kernel: [36022.441684] bcm2835-v4l2: queue_setup: capture port not configured
消息:
Feb 19 20:02:10 raspberrypi kernel: [ 90.555578] ------------[ cut here ]------------
Feb 19 20:02:10 raspberrypi kernel: [ 90.555698] WARNING: CPU: 0 PID: 3593 at drivers/media/v4l2-core/videobuf2-core.c:2135 __vb2_queue_cancel+0xf4/0x160 [videobuf2_core]()
Feb 19 20:02:10 raspberrypi kernel: [ 90.555715] Modules linked in: evdev uinput rfcomm bnep bcm2835_v4l2 videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media snd_bcm2835 snd_pcm snd_seq snd_seq_device snd_timer snd spi_bcm2708 i2c_bcm2708 i2c_dev ecb btusb 8192cu bluetooth rfkill uio_pdrv_genirq uio
Feb 19 20:02:10 raspberrypi kernel: [ 90.555843] CPU: 0 PID: 3593 Comm: v4l2-ctl Not tainted 3.18.7+ #755
Feb 19 20:02:10 raspberrypi kernel: [ 90.555915] [<c00151fc>] (unwind_backtrace) from [<c0012710>] (show_stack+0x20/0x24)
Feb 19 20:02:10 raspberrypi kernel: [ 90.556012] [<c0012710>] (show_stack) from [<c0555b30>] (dump_stack+0x20/0x28)
Feb 19 20:02:10 raspberrypi kernel: [ 90.556053] [<c0555b30>] (dump_stack) from [<c0022ef4>] (warn_slowpath_common+0x7c/0x9c)
Feb 19 20:02:10 raspberrypi kernel: [ 90.556083] [<c0022ef4>] (warn_slowpath_common) from [<c0022fd0>] (warn_slowpath_null+0x2c/0x34)
Feb 19 20:02:10 raspberrypi kernel: [ 90.556143] [<c0022fd0>] (warn_slowpath_null) from [<bf263a1c>] (__vb2_queue_cancel+0xf4/0x160 [videobuf2_core])
Feb 19 20:02:10 raspberrypi kernel: [ 90.556252] [<bf263a1c>] (__vb2_queue_cancel [videobuf2_core]) from [<bf265548>] (vb2_internal_streamoff+0x40/0xdc [videobuf2_core])
Feb 19 20:02:10 raspberrypi kernel: [ 90.556361] [<bf265548>] (vb2_internal_streamoff [videobuf2_core]) from [<bf2656d8>] (vb2_streamoff+0x3c/0x60 [videobuf2_core])
Feb 19 20:02:10 raspberrypi kernel: [ 90.556436] [<bf2656d8>] (vb2_streamoff [videobuf2_core]) from [<bf26574c>] (vb2_ioctl_streamoff+0x50/0x54 [videobuf2_core])
Feb 19 20:02:10 raspberrypi kernel: [ 90.556669] [<bf26574c>] (vb2_ioctl_streamoff [videobuf2_core]) from [<bf228658>] (v4l_streamoff+0x28/0x2c [videodev])
Feb 19 20:02:10 raspberrypi kernel: [ 90.556938] [<bf228658>] (v4l_streamoff [videodev]) from [<bf22baf4>] (__video_do_ioctl+0x254/0x2e8 [videodev])
Feb 19 20:02:10 raspberrypi kernel: [ 90.557182] [<bf22baf4>] (__video_do_ioctl [videodev]) from [<bf22b49c>] (video_usercopy+0x180/0x560 [videodev])
Feb 19 20:02:10 raspberrypi kernel: [ 90.557414] [<bf22b49c>] (video_usercopy [videodev]) from [<bf22b898>] (video_ioctl2+0x1c/0x24 [videodev])
Feb 19 20:02:10 raspberrypi kernel: [ 90.557616] [<bf22b898>] (video_ioctl2 [videodev]) from [<bf2266b0>] (v4l2_ioctl+0x11c/0x14c [videodev])
Feb 19 20:02:10 raspberrypi kernel: [ 90.557791] [<bf2266b0>] (v4l2_ioctl [videodev]) from [<c014c478>] (do_vfs_ioctl+0x3f0/0x5d4)
Feb 19 20:02:10 raspberrypi kernel: [ 90.557872] [<c014c478>] (do_vfs_ioctl) from [<c014c6a0>] (SyS_ioctl+0x44/0x6c)
Feb 19 20:02:10 raspberrypi kernel: [ 90.557917] [<c014c6a0>] (SyS_ioctl) from [<c000e8c0>] (ret_fast_syscall+0x0/0x48)
Feb 19 20:02:10 raspberrypi kernel: [ 90.557936] ---[ end trace 28c9150399e29093 ]---
Feb 19 20:52:43 raspberrypi kernel: [ 3123.544118] ------------[ cut here ]------------
Feb 19 20:52:43 raspberrypi kernel: [ 3123.544235] WARNING: CPU: 0 PID: 28629 at drivers/media/v4l2-core/videobuf2-core.c:2135 __vb2_queue_cancel+0xf4/0x160 [videobuf2_core]()
Feb 19 20:52:43 raspberrypi kernel: [ 3123.544251] Modules linked in: evdev uinput rfcomm bnep bcm2835_v4l2 videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media snd_bcm2835 snd_pcm snd_seq snd_seq_device snd_timer snd spi_bcm2708 i2c_bcm2708 i2c_dev ecb btusb 8192cu bluetooth rfkill uio_pdrv_genirq uio
Feb 19 20:52:43 raspberrypi kernel: [ 3123.544404] CPU: 0 PID: 28629 Comm: v4l2-ctl Tainted: G W 3.18.7+ #755
Feb 19 20:52:43 raspberrypi kernel: [ 3123.544475] [<c00151fc>] (unwind_backtrace) from [<c0012710>] (show_stack+0x20/0x24)
Feb 19 20:52:43 raspberrypi kernel: [ 3123.544570] [<c0012710>] (show_stack) from [<c0555b30>] (dump_stack+0x20/0x28)
Feb 19 20:52:43 raspberrypi kernel: [ 3123.544676] [<c0555b30>] (dump_stack) from [<c0022ef4>] (warn_slowpath_common+0x7c/0x9c)
Feb 19 20:52:43 raspberrypi kernel: [ 3123.545092] [<c0022ef4>] (warn_slowpath_common) from [<c0022fd0>] (warn_slowpath_null+0x2c/0x34)
Feb 19 20:52:43 raspberrypi kernel: [ 3123.545178] [<c0022fd0>] (warn_slowpath_null) from [<bf263a1c>] (__vb2_queue_cancel+0xf4/0x160 [videobuf2_core])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.545253] [<bf263a1c>] (__vb2_queue_cancel [videobuf2_core]) from [<bf265548>] (vb2_internal_streamoff+0x40/0xdc [videobuf2_core])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.545316] [<bf265548>] (vb2_internal_streamoff [videobuf2_core]) from [<bf2656d8>] (vb2_streamoff+0x3c/0x60 [videobuf2_core])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.545377] [<bf2656d8>] (vb2_streamoff [videobuf2_core]) from [<bf26574c>] (vb2_ioctl_streamoff+0x50/0x54 [videobuf2_core])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.545562] [<bf26574c>] (vb2_ioctl_streamoff [videobuf2_core]) from [<bf228658>] (v4l_streamoff+0x28/0x2c [videodev])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.545803] [<bf228658>] (v4l_streamoff [videodev]) from [<bf22baf4>] (__video_do_ioctl+0x254/0x2e8 [videodev])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.546060] [<bf22baf4>] (__video_do_ioctl [videodev]) from [<bf22b49c>] (video_usercopy+0x180/0x560 [videodev])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.546309] [<bf22b49c>] (video_usercopy [videodev]) from [<bf22b898>] (video_ioctl2+0x1c/0x24 [videodev])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.546483] [<bf22b898>] (video_ioctl2 [videodev]) from [<bf2266b0>] (v4l2_ioctl+0x11c/0x14c [videodev])
Feb 19 20:52:43 raspberrypi kernel: [ 3123.546595] [<bf2266b0>] (v4l2_ioctl [videodev]) from [<c014c478>] (do_vfs_ioctl+0x3f0/0x5d4)
Feb 19 20:52:43 raspberrypi kernel: [ 3123.546676] [<c014c478>] (do_vfs_ioctl) from [<c014c6a0>] (SyS_ioctl+0x44/0x6c)
Feb 19 20:52:43 raspberrypi kernel: [ 3123.546717] [<c014c6a0>] (SyS_ioctl) from [<c000e8c0>] (ret_fast_syscall+0x0/0x48)
Feb 19 20:52:43 raspberrypi kernel: [ 3123.546737] ---[ end trace 28c9150399e29094 ]---
最佳答案
通过查看您的内核消息，特别是包含“__vb2_queue_cancel”的行，我认为您的问题可能部分与 Raspberry 的内核驱动程序有关。您是否检查过您的内核是否包含 [1] 中给出的修复程序？如果没有，应用该 oneliner 可能会解决您的问题。
由于某种原因，您的相机应用程序正在停止视频捕获，并且由于上述错误，它未能这样做。这至少可以让您有机会重新启动捕获管道。
[1] https://github.com/6by9/linux/commit/f1e870c2c910d0620b1a48ac7165c8f9e9a75527
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什么是ruby的rack或python的Java的wsgi？还有一个路由库。 最佳答案 来自Python标准PEP333:Bycontrast,althoughJavahasjustasmanywebapplicationframeworksavailable,Java's"servlet"APImakesitpossibleforapplicationswrittenwithanyJavawebapplicationframeworktoruninanywebserverthatsupportstheservletAPI.ht
华为OD机试题本篇题目：明明的随机数题目输入描述输出描述：示例1输入输出说明代码编写思路最近更新的博客华为od2023|什么是华为od，od薪资待遇，od机试题清单华为OD机试真题大全，用Python解华为机试题|机试宝典【华为OD机试】全流程解析+经验分享,题型分享,防作弊指南华为o
我想解析一个已经存在的.mid文件，改变它的乐器，例如从“acousticgrandpiano”到“violin”，然后将它保存回去或作为另一个.mid文件。根据我在文档中看到的内容，该乐器通过program_change或patch_change指令进行了更改，但我找不到任何在已经存在的MIDI文件中执行此操作的库.他们似乎都只支持从头开始创建的MIDI文件。 最佳答案 MIDIpackage会为您完成此操作，但具体方法取决于midi文件的原始内容。一个MIDI文件由一个或多个音轨组成，每个音轨是十六个channel中任何一个上的
本文主要介绍在使用Selenium进行自动化测试或者任务时，对于使用了iframe的页面，如何定位iframe中的元素文章目录场景描述解决方案具体代码场景描述当我们在使用Selenium进行自动化测试的时候，可能会遇到一些界面或者窗体是使用HTML的iframe标签进行承载的。对于iframe中的标签，如果直接查找是无法找到的，会抛出没有找到元素的异常。比如近在咫尺的例子就是，CSDN的登录窗体就是使用的iframe，大家可以尝试通过F12开发者模式查看到的tag_name,class_name,id或者xpath来定位中的页面元素，会抛出NoSuchElementException异常。解决
2022/8/4更新支持加入水印水印必须包含透明图像，并且水印图像大小要等于原图像的大小pythonconvert_image_to_video.py-f30-mwatermark.pngim_dirout.mkv2022/6/21更新让命令行参数更加易用新的命令行使用方法pythonconvert_image_to_video.py-f30im_dirout.mkvFFMPEG命令行转换一组JPG图像到视频时，是将这组图像视为MJPG流。我需要转换一组PNG图像到视频，FFMPEG就不认了。pyav内置了ffmpeg库，不需要系统带有ffmpeg工具因此我使用ffmpeg的python包装p
📢博客主页：https://blog.csdn.net/weixin_43197380📢欢迎点赞👍收藏⭐留言📝如有错误敬请指正！📢本文由Loewen丶原创，首发于CSDN，转载注明出处🙉📢现在的付出，都会是一种沉淀，只为让你成为更好的人✨文章预览：一.分辨率（Resolution）1、工业相机的分辨率是如何定义的？2、工业相机的分辨率是如何选择的？二.精度（Accuracy）1、像素精度（PixelAccuracy）2、定位精度和重复定位精度（RepeatPrecision）三.公差（Tolerance）四.课后作业（Post-ClassExercises）视觉行业的初学者，甚至是做了1~2年
ValidPalindromeGivenastring,determineifitisapalindrome,consideringonlyalphanumericcharactersandignoringcases. [#125]Example:"Aman,aplan,acanal:Panama"isapalindrome."raceacar"isnotapalindrome.Haveyouconsiderthatthestringmightbeempty?Thisisagoodquestiontoaskduringaninterview.Forthepurposeofthisproblem
是否可以在PyYAML或Ruby的Psych引擎中禁用创建anchor和引用(并有效地显式列出冗余数据)？也许我在网上搜索时遗漏了一些东西，但在Psych中似乎没有太多可用的选项，而且我也无法确定PyYAML是否允许这样做.基本原理是我必须序列化一些数据并将其以可读的形式传递给一个不是真正的技术同事进行手动验证。有些数据是多余的，但我需要以最明确的方式列出它们以提高可读性(anchor和引用是提高效率的好概念，但不是人类可读性)。Ruby和Python是我选择的工具，但如果有其他一些相当简单的方法来“展开”YAML文档，它可能就可以了。 最佳答案