如果遇到这个问题的话：

coolpi@car-c:~$ gst-launch-1.0 v4l2src device=/dev/video11 ! video/x-raw,format=NV12,width=1920,height=1080,framerate=25/1 ! videoflip method=vertical-flip !  mpph264enc ! rtspclientsink latency=0 location=rtsp://192.168.0.100:554/test
Setting pipeline to PAUSED ...
ERROR: Pipeline doesn't want to pause.
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Could not open device '/dev/video11' for reading and writing.
Additional debug info:
v4l2_calls.c(621): gst_v4l2_open (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
system error: Permission denied
Setting pipeline to NULL ...
Freeing pipeline ...

执行命令前加上sudo，给上权限，摄像头就能用了

@gongxing 5v/12v都可以供电

coolpi 4b能否使用12v电源供电呢？

如果遇到这个问题的话：

coolpi@car-c:~$ gst-launch-1.0 v4l2src device=/dev/video11 ! video/x-raw,format=NV12,width=1920,height=1080,framerate=25/1 ! videoflip method=vertical-flip !  mpph264enc ! rtspclientsink latency=0 location=rtsp://192.168.0.100:554/test
Setting pipeline to PAUSED ...
ERROR: Pipeline doesn't want to pause.
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Could not open device '/dev/video11' for reading and writing.
Additional debug info:
v4l2_calls.c(621): gst_v4l2_open (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
system error: Permission denied
Setting pipeline to NULL ...
Freeing pipeline ...

执行命令前加上sudo，给上权限，摄像头就能用了