Records explorer

Drop a data file that holds a table of records, or a network capture of a game's messages. Each record or message becomes a row, and each byte a coloured cell, so fields line up as columns. A flat column is a constant, such as a magic number or a version. A smooth ramp is a counter. Noise is data. The strip above the grid marks what each column looks like: constant, counter, length, or a few values that may be the message type. Group the rows by that byte to see each type's own layout.

For a data file, the explorer suggests record sizes from the distances at which bytes repeat. Try the first suggestion, then step the size by one until the columns stand straight. For a capture (.pcap or .pcapng from Wireshark or tcpdump), choose a flow and a direction.

In a project, tools/formats/fields.py prints the same table and draws the same picture, and tools/formats/pcap.py lists and extracts the flows. Network games covers capturing and reading a protocol.