E edwardzhou
Nov 23, 2023, 8:25 AM

uname -a
Linux Ubuntu 5.10.110 #5 SMP Thu Mar 2 17:39:26 CST 2023 aarch64 aarch64 aarch64 GNU/Linux

系统是论坛上下载的Ubuntu

cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.04
DISTRIB_CODENAME=jammy
DISTRIB_DESCRIPTION="Ubuntu 22.04.3 LTS"

USB摄像头：

(rknn_py39) edwardzhou@Ubuntu:~/opencv_work/build$ v4l2-ctl -d /dev/video20 --all
Driver Info:
	Driver name      : uvcvideo
	Card type        : USB PHY 2.0: USB CAMERA
	Bus info         : usb-fc800000.usb-1.3
	Driver version   : 5.10.110
	Capabilities     : 0x84a00001
		Video Capture
		Metadata Capture
		Streaming
		Extended Pix Format
		Device Capabilities
	Device Caps      : 0x04200001
		Video Capture
		Streaming
		Extended Pix Format
Media Driver Info:
	Driver name      : uvcvideo
	Model            : USB PHY 2.0: USB CAMERA
	Serial           :
	Bus info         : usb-fc800000.usb-1.3
	Media version    : 5.10.110
	Hardware revision: 0x00000100 (256)
	Driver version   : 5.10.110
Interface Info:
	ID               : 0x03000002
	Type             : V4L Video
Entity Info:
	ID               : 0x00000001 (1)
	Name             : USB PHY 2.0: USB CAMERA
	Function         : V4L2 I/O
	Flags            : default
	Pad 0x01000007   : 0: Sink
	  Link 0x02000013: from remote pad 0x100000a of entity 'Extension 4' (Video Pixel Formatter): Data, Enabled, Immutable
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
	Width/Height      : 640/480
	Pixel Format      : 'MJPG' (Motion-JPEG)
	Field             : None
	Bytes per Line    : 0
	Size Image        : 4177920
	Colorspace        : sRGB
	Transfer Function : Rec. 709
	YCbCr/HSV Encoding: ITU-R 601
	Quantization      : Default (maps to Full Range)
	Flags             :
Crop Capability Video Capture:
	Bounds      : Left 0, Top 0, Width 640, Height 480
	Default     : Left 0, Top 0, Width 640, Height 480
	Pixel Aspect: 1/1
Selection Video Capture: crop_default, Left 0, Top 0, Width 640, Height 480, Flags:
Selection Video Capture: crop_bounds, Left 0, Top 0, Width 640, Height 480, Flags:
Streaming Parameters Video Capture:
	Capabilities     : timeperframe
	Frames per second: 30.000 (30/1)
	Read buffers     : 0
      white_balance_temperature 0x0098091a (int)    : min=0 max=255 step=1 default=128 value=128

发现有两个问题:

  1. usb摄像头如果接 USB3.0的那两个蓝色接口，无法工作，gst打不开。接 USB2.0的插口，才能工作。

  2. 用gst-launch-1.0 测试
    1) 有时会直接失败, 再次又能成功
    失败日志:

(rknn_py39) edwardzhou@Ubuntu:~/opencv_work/build$ gst-launch-1.0 v4l2src device=/dev/video20 ! image/jpeg,width=640,height=480 ! jpegparse !  mppjpegdec ! videoconvert ! appsink
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
libv4l2: error turning on stream: Input/output error
ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Failed to allocate required memory.
Additional debug info:
../sys/v4l2/gstv4l2src.c(800): 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 0:00:00.067890509
Setting pipeline to NULL ...
Freeing pipeline ...

2) 能成功拉取，过十几秒又会自动中断
开始成功的输出

(rknn_py39) edwardzhou@Ubuntu:~/opencv_work/build$ gst-launch-1.0 v4l2src device=/dev/video20 ! image/jpeg,width=640,height=480 ! jpegparse !  mppjpegdec ! videoconvert ! appsink
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
Redistribute latency...
0:00:07.9 / 99:99:99.

拉取过十几秒后失败 自动断开

rknn_py39) edwardzhou@Ubuntu:~/opencv_work/build$ gst-launch-1.0 v4l2src device=/dev/video20 ! image/jpeg,width=640,height=480 ! jpegparse !  mppjpegdec ! videoconvert ! appsink
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock
Redistribute latency...
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 error (-5)
Execution ended after 0:00:13.670819439
Setting pipeline to NULL ...
Freeing pipeline ...