Video Encode with highest quality on Jetson Nano

I need to improve the quality of videos encoded on Jetson Nano captured from A USB 3 camera. I want the highest possible quality that the Nano can give.
This the pipeline I am currently using

gst-launch-1.0 -e v4l2src device=/dev/video0  ! 'video/x-raw, width=(int)3840, height=(int)1080, framerate=(fraction)30/1' ! queue ! nvvidconv ! nvv4l2h264enc maxperf-enable=1 bitrate=16000000 ! h264parse ! mux. pulsesrc ! audio/x-raw,rate=48000,channels=2 ! queue ! audioconvert ! queue ! opusenc bitrate=512000 ! mpegtsmux name=mux ! filesink location="jaH264.mp4"

I can tell that the video quality is inferior to when I record using the same camera on a windows machine. Moreover the video is not playble on Iphone.

What is the best gstreamer pipeline that will give me the best quality video which is also playble on Iphone?

Thanks

v4l2-ctl -d /dev/video0 --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
Index : 0
Type : Video Capture
Pixel Format: ‘YUYV’
Name : YUYV 4:2:2
Size: Discrete 1920x1080
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 1280x720
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.037s (27.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 960x544
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.037s (27.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 640x360
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.037s (27.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 3840x1080
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.037s (27.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 3840x1088
Interval: Discrete 0.033s (30.000 fps)
Interval: Discrete 0.037s (27.000 fps)
Interval: Discrete 0.042s (24.000 fps)
Interval: Discrete 0.067s (15.000 fps)
Size: Discrete 4800x1200
Interval: Discrete 0.067s (15.000 fps)

You may try main or high H264 profile (nvv4l2h264enc property profile=2 or =4).

Thanks @Honey_Patouceul but no improvement in the quality, also still not playable on Iphone.

Hi,
Please try to set CBR + virtual buffer size:
Random blockiness in the picture RTSP server-client -Jetson TX2 - #5 by DaneLLL