What do the generated default file names, such as 111.52532, represent respectively? What is the naming rule?

[fighter-01]

[sz3]

The first number is "encode id". It increases sequentially every time a new file is encoded, and loops at 127 since only 7 bits are used. Its main purpose is to allow multiple files of the same size to be decoded within the same session. (it starts at 109 for arbitrary-yet-slightly-interesting bit pattern reasons to give the color correction more to work with...)

The second number is the compressed file size. Combined, the encode_id+size pair is treated as a unique id for the data -- decoded frames that match are collected under whatever their id is. The current naming scheme (until filename support is added) just reflects that back to the user. 🙂

[fighter-01]

If two files are of the same size, does it mean that their names are the same, for example, both are 111.52532?

[sz3]

If two files are of the same size, does it mean that their names are the same, for example, both are 111.52532?

The second number will be the same. The full name will be the same only if the autoincrementing encode_id (the first number) happens to be the same.