VOSPlayer For Linux

All VOS-related data structures are in little-endian format. Strings are encoded as: struct string { u8 len; char val[len]; }; File structure: (from beyer85.vos) 0x00: "\x03\x00\x00\x00" 0x04: Segment table: struct seg { u32 offset; /* Offset of the segment in the file */ char name[16]; /* "inf", "mid", "EOF" */ } segs[variable]; /* The last segment is "EOF" */ The "inf" segment: Before the inf_header, there can be an optional "VOS1" header: struct vos1_header { char magic[4]; /* "VOS1" */ u16 version; /* Usually 1 */ char dummy[64]; /* Usually all zeros */ string str1; }; struct inf_header { string title; /* Song title */ string artist; /* Artist of the original song */ string comment; /* Unknown; in beyer** it is "Step xx" where xx is the difficulty level, but it can also be empty */ string vos_author; /* Author of the VOS */ u8 song_type; /* Probably things like "Classical" or "NewAge" */ u8 extended_type; u32 length; /* The unit is approx. 1/974 sec (1024us?) */ u8 level; /* The shown level minus 1 */ char dummy[1023]; /* Seems to be zeroed out */ }; After the "inf" header, there is a list of note_arrays. The last note array just collects the user-played notes in the other note arrays. struct note_array { u32 type; /* Instrument? */ u32 nnote; /* Number of notes */ char dummy2[14]; /* Seems to be always zero */ note notes[nnote]; } struct note { u32 time; u32 len; /* Length of the note */ char midi[3]; /* The MIDI key-down command */ u16 mode; /* Bit 0-3: color (?); 4-6: corresponding key (do,re,mi,fa,so,la,ti); Bit 7: set for notes played by the user; Bit 8: set for long notes. */ char unknown2[2]; /* what? The first byte can be 0x80 or 0xB0 or 0xD0, ... Is it the length? */ }; The "mid" segment: An ordinary MIDI file, but seems to contain initialization stuff only (please investigate further).