Exporting the flows in Json after running nDPI gives wrong source + destination ports.
The function (line 1606 in example/ndpiReader.c):

static void printFlowSerialized(u_int16_t thread_id, struct ndpi_flow_info *flow) {
..
ndpi_serialize_string_uint32(serializer, "src_port", flow->src_port);
ndpi_serialize_string_uint32(serializer, "dst_port", flow->dst_port);
..
}

should be:

static void printFlowSerialized(u_int16_t thread_id, struct ndpi_flow_info *flow) {
..
ndpi_serialize_string_uint32(serializer, "src_port", ntohs(flow->src_port));
ndpi_serialize_string_uint32(serializer, "dst_port", ntohs(flow->dst_port));
..
}