How to convert 3840x2160 frame to 1280x1280 in gstreamer pipelines?

[jasonrichdarmawan]

I tried your Python code. Please try to display the frame as 256x256 → "nvvidconv ! video/x-raw, format=(string)BGRx, width=256, height=256 ! ".

Perhaps your monitor resolution is 1920x1080, that’s was also my case. I thought the display frame did not have black pixels.

Regarding running it with gst-launch-1.0, I changed the width=1080,height=1080 for the display frame to match the monitor resolution. This is because the monitor resolution over 1920x1080 is too small for me to read. My monitor resolution is 1920x1080.

I also use HDMI Video Capture to USB. This is because I only have 1 monitor. To clarify, I use OBS Studio to display NVIDIA Jetson Nano B01 GUI through HDMI Video Capture device. Not sure if this affect.

All of the gst-launch-1.0 have black pixels.

Solution:

def gstreamer_pipeline(
    # Issue: the sensor format used by Raspberry Pi 4B and NVIDIA Jetson Nano B01 are different
    # in Raspberry Pi 4B, this command
    # $ libcamera-still --width 1280 --height 1280 --mode 1280:1280
    # uses sensor format 2328x1748.
    # However, v4l2-ctl --list-formats-ext do not have such format.
    capture_width=3840,
    capture_height=2160,
    display_width=640,
    display_height=360,
    framerate=21,
    flip_method=0,
):
    return (
        "nvarguscamerasrc ! "
        "video/x-raw(memory:NVMM),width=(int)%d,height=(int)%d,format=(string)NV12,framerate=(fraction)%d/1 ! "
        "nvvidconv flip-method=%d left=%d right=%d top=%d bottom=%d ! "
        "video/x-raw, width=(int)%d, height=(int)%d, format=(string)BGRx ! "
        "videoconvert ! "
        "video/x-raw, format=(string)BGR ! appsink"
        % (
            capture_width,
            capture_height,
            framerate,
            flip_method,
            capture_width/2 - display_width/2,
            capture_width/2 + display_width/2,
            capture_height/2 - display_height/2,
            capture_height/2 + display_height/2,
            display_width,
            display_height
        )
    )

Reference: R32.3.1 tx2-4g nvvidconv problem - #21 by Honey_Patouceul