Jetson Nano DeepStream-5.0 IP camera issue

Previously, I developed the program from Deepstream 4.0.1 to QT, It was used in h.264 format. Due to the problem of the camera delay, it was changed to mjpeg format and used. I used Deepstream 5.0 refer to the following article.

However, your answer this time was that the mjpeg format cannot be used in Deepstream. I checked that camera streaming was working on the destream-app sample, but there was a problem that the program ended irregularly. I want know if the support for mjpeg format is incomplete or not fully available.
And
mjpeg : 300ms
h.264 : 600ms
There is a delay I wonder if I can reduce the delay of h.264
Thank you.