Reverse engineering the waveform format of the Rigol DS4000 series of
oscilloscopes. The format is in wfm4.ksy described using Kaitai
Struct's language. A generated parser for C++ is in
wfm4.cpp and wfm4.h.
The settings of the oscilloscope seem to be in the range 0x00-0xEC1. After that, the range 0xEC2-0x51EB seems to be filled by random data (after the oscilloscope boots) or partial data from the last saved file (after a file has been saved). The remaining data starting at offset 0x51EC contains the channel data and padding. If an exported channel's coupling is set to GND, its data will apparently be an AC measurement instead.