我正在尝试用来mencoder录制视频。以下命令取自在线教程：
mencoder tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0:forceaudio:adevice=/dev/dsp -ovc lavc -oac mp3lame -lameopts cbr:br=64:mode=3 -o filename.avi
输出如下：
MEncoder SVN-r37379 (C) 2000-2015 MPlayer Team
210 audio & 441 video codecs
success: format: 9 data: 0x0 - 0x0
TV file format detected.
Selected driver: v4l2
name: Video 4 Linux 2 input
author: Martin Olschewski <olschewski@zpr.uni-koeln.de>
comment: first try, more to come ;-)
v4l2: your device driver does not support VIDIOC_G_STD ioctl, VIDIOC_G_PARM was used instead.
Selected device: UVC Camera (046d:0825)
Capabilities: video capture streaming
supported norms:
inputs: 0 = Camera 1;
Current input: 0
Current format: YUYV
tv.c: norm_from_string(pal): Bogus norm parameter, setting default.
v4l2: ioctl enum norm failed: Inappropriate ioctl for device
Error: Cannot set norm!
Selected input hasn't got a tuner!
Unable to open '/dev/dsp': No such file or directory
Unable to open '/dev/dsp': No such file or directory
Unable to open '/dev/dsp': No such file or directory
v4l2: ioctl set mute failed: Invalid argument
v4l2: 0 frames successfully processed, 0 frames dropped.
============ Sorry, this file format is not recognized/supported =============
=== If this file is an AVI, ASF or MPEG stream, please contact the author! ===
Cannot open demuxer.
Exiting...
user@ArchBox:~/Dropbox$ mencoder tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0:forceaudio:ade[15838:17998:0117/045341:ERROR:cert_verify_proc_nss.cc(922)] CERT_PKIXVerifyCert for api.tldr.io failed err=-8181
我该如何解决这些错误？