Hi
I’m using a USB camera to check the video in both image/jpeg and video/x-raw.
※ Information about the USB camera can be found under the case.
Comparing the photos attached below, video/x-raw looks clearer.
What is the reason for this?
Also, when I move my hand in front of the camera, the video/x-raw reacts in real time and the image/jpeg has a delay.
Please tell me the reason for this.
Here is my Jetpack information.
$ cat /etc/nv_tegra_release
# R35 (release), REVISION: 1.0, GCID: 31346300, BOARD: t186ref, EABI: aarch64, DATE: Thu Aug 25 18:41:45 UTC 2022
The image is the code obtained with image/jpeg.
cap = cv2.VideoCapture ('v4l2src device=/dev/video0 io-mode=2 ! image/jpeg, width= 640, height= 480, framerate=61612/513 ! nvv4l2decoder mjpeg=1 ! nvvidconv ! video/x-raw,format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink', cv2.CAP_GSTREAMER)
The image is the code obtained with video/x-raw.
cap = cv2.VideoCapture('v4l2src device=/dev/video0 io-mode=2 ! video/x-raw, width=640, height=480, framerate=30/1 ! videoconvert ! video/x-raw,format=BGR ! appsink', cv2.CAP_GSTREAMER)
Device found:
name : HD USB Camera: HD USB Camera
class : Video/Source
caps : video/x-raw, format=(string)YUY2, width=(int)1920, height=(int)1080, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)6/1;
video/x-raw, format=(string)YUY2, width=(int)1280, height=(int)1024, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)6/1;
video/x-raw, format=(string)YUY2, width=(int)1280, height=(int)720, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)9/1;
video/x-raw, format=(string)YUY2, width=(int)1024, height=(int)768, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)6/1;
video/x-raw, format=(string)YUY2, width=(int)800, height=(int)600, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)20/1;
video/x-raw, format=(string)YUY2, width=(int)640, height=(int)480, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)30/1;
video/x-raw, format=(string)YUY2, width=(int)320, height=(int)240, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)30/1;
image/jpeg, width=(int)1920, height=(int)1080, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)30/1;
image/jpeg, width=(int)1280, height=(int)1024, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)30/1;
image/jpeg, width=(int)1280, height=(int)720, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)60/1;
image/jpeg, width=(int)1024, height=(int)768, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)30/1;
image/jpeg, width=(int)800, height=(int)600, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)60/1;
image/jpeg, width=(int)640, height=(int)480, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)61612/513;
image/jpeg, width=(int)320, height=(int)240, pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)61612/513;
properties:
udev-probed = true
device.bus_path = platform-3610000.xhci-usb-0:4.1:1.0
sysfs.path = /sys/devices/platform/3610000.xhci/usb1/1-4/1-4.1/1-4.1:1.0/video4linux/video0
device.bus = usb
device.subsystem = video4linux
device.vendor.id = 32e4
device.vendor.name = "HD\\x20USB\\x20Camera"
device.product.id = 9230
device.product.name = "HD\ USB\ Camera:\ HD\ USB\ Camera"
device.serial = HD_USB_Camera_HD_USB_Camera
device.capabilities = :capture:
device.api = v4l2
device.path = /dev/video0
v4l2.device.driver = uvcvideo
v4l2.device.card = "HD\ USB\ Camera:\ HD\ USB\ Camera"
v4l2.device.bus_info = usb-3610000.xhci-4.1
v4l2.device.version = 330344 (0x00050a68)
v4l2.device.capabilities = 2225078273 (0x84a00001)
v4l2.device.device_caps = 69206017 (0x04200001)
gst-launch-1.0 v4l2src ! ...
