@Kzyh when I set padding='valid' instead of padding=same then model.summary is:
_________________________________________________________________
Layer (type)                 Output Shape              Param #   
=================================================================
conv2d_1 (Conv2D)            (None, 128, 800, 16)      304       
_________________________________________________________________
batch_normalization (BatchNo (None, 128, 800, 16)      64        
_________________________________________________________________
max_pooling2d (MaxPooling2D) (None, 25, 200, 16)       0         
_________________________________________________________________
conv2d_2 (Conv2D)            (None, 25, 200, 8)        520       
_________________________________________________________________
batch_normalization_1 (Batch (None, 25, 200, 8)        32        
_________________________________________________________________
max_pooling2d_1 (MaxPooling2 (None, 4, 40, 8)          0         
_________________________________________________________________
time_distributed (TimeDistri (None, 4, 320)            0         
_________________________________________________________________
bidirectional (Bidirectional (None, 16)                21056     
_________________________________________________________________
dense (Dense)                (None, 7)                 119       
=================================================================
Total params: 22,095
Trainable params: 22,047
Non-trainable params: 48