the reason to add this layer first is that vf_sr uses it in its tensorflow model, and the next plan is to update the python script to convert tf.pad into native model.
df8db34552 dnn: add layer pad which is equivalent to tf.pad
libavfilter/dnn/Makefile | 1 +
libavfilter/dnn/dnn_backend_native_layer_pad.c | 211 +++++++++++++++++++++++++
libavfilter/dnn/dnn_backend_native_layer_pad.h | 40 +++++
3 files changed, 252 insertions(+)