我曾在Ubuntu 19.04上尝试过example
gst-launch-1.0 videotestsrc ! v4l2sink device=/dev/video10
但是gstreamer失败
Setting pipeline to PAUSED ...
ERROR: Pipeline doesn't want to pause.
ERROR: from element /GstPipeline:pipeline0/GstV4l2Sink:v4l2sink0: Cannot identify device '/dev/video10'.
Additional debug info:
v4l2_calls.c(609): gst_v4l2_open (): /GstPipeline:pipeline0/GstV4l2Sink:v4l2sink0:
system error: No such file or directory
Setting pipeline to NULL ...
Freeing pipeline ...
为什么不起作用？我在文档中没有找到这个，是否需要以某种方式创建/ dev / video10？
我对默认设备/ dev / video1做了同样的操作，但它是我的笔记本电脑上的输入摄像头设备：
sudo gst-launch-1.0 videotestsrc ! v4l2sink
Setting pipeline to PAUSED ...
ERROR: Pipeline doesn't want to pause.
ERROR: from element /GstPipeline:pipeline0/GstV4l2Sink:v4l2sink0: Device '/dev/video1' is not a output device.
Additional debug info:
v4l2_calls.c(639): gst_v4l2_open (): /GstPipeline:pipeline0/GstV4l2Sink:v4l2sink0:
Capabilities: 0x4a00000
Setting pipeline to NULL ...
Freeing pipeline ...
提前感谢。
您的问题的标题表明您想写入虚拟视频设备。 v4l2设备可以是输入和输出视频设备。您的相机是视频输入（捕获）设备。在gstreamer中引导v4l2sink（因此是管道的端点）可能会失败。
但是您可以生成虚拟输出设备。您正在寻找的是v4l2-loopback设备。它允许您生成虚拟/dev/video10设备，如下所示：
modprobe v4l2loopback video_nr=10