Other posts about alignment:
https://devtalk.nvidia.com/default/topic/1022415/jetson-tx2/gstvideoencode-not-working/post/5204286/#5204286
https://devtalk.nvidia.com/default/topic/1023050/jetson-tk1/nvvidconv-issue-when-transform-non-standard-video/post/5205513/#5205513
and a sample verified on r28.2/TX2
$ g++ -Wall -std=c++11 a.cpp -o test $(pkg-config --cflags --libs gstreamer-app-1.0) -ldl
$ gst-launch-1.0 videotestsrc num-buffers=1 ! video/x-raw,format=I420,width=2896,height=2896 ! filesink location=a.yuv
$ ./test
$ gst-launch-1.0 filesrc location= a.mp4 ! qtdemux ! h264parse ! omxh264dec ! nvvidconv ! 'video/x-raw(memory:NVMM),width=1024,height=1024' ! nvoverlaysink
a.cpp (2.59 KB)