editcap from Linux cooked capture to Ethernet packet

Editcap, alone, won't help here. As I stated in a comment on your other related question, editcap does NOT transform the contents of packets; it will not, for example, take packets with Linux cooked capture headers, remove the cooked capture headers, construct Ethernet headers by:

• using the link-layer address (assuming it's 6 octets long; if not, it'd have to construct a fake one) as the source or destination address depending on whether the packet was sent by or received by the capturing host;
• construct a fake address for the other MAC address;
• construct a type/length field value depending on the "protocol type" field;

and then prepend the resulting header.

text2pcap might help here, but it's not sufficient. You could take the packets, print their time stamps and raw hex data, write a program (in whatever language) to do the transformation described above and write the resulting file out, and then turn it into a pcap file using text2pcap.

The "write a program" step is the key one; I'm not sure there are any existing programs that will take a Linux cooked capture and generate an Ethernet capture.