lifeblack:

How to change it that the output be [16,64, 256, 448, 1]


You can add padding to the convolution to keep the spatial sizes.



 lifeblack:

then, I pass this tensor over a conv layer […]


The conv_2 layer uses a kernel size of 64 in the last spatial dimension, while the activation input has a size of 1 in this dim. This won’t work, since the (padded) input activation needs to have at least the same size as the kernel.