A binlog file starts with a Binlog File
Header [ fe 'bin' ]
$ hexdump -C /tmp/binlog-test.log
00000000 fe 62 69 6e 19 6f c9 4c 0f 01 00 00 00 66 00 00 |.bin.o.L.....f..|
00000010 00 6a 00 00 00 00 00 04 00 6d 79 73 71 6c 2d 70 |.j.......mysql-p|
00000020 72 6f 78 79 2d 30 2e 37 2e 30 00 00 00 00 00 00 |roxy-0.7.0......|
...