The collection header chunk contains a single number, which is the number of instruments defined in the DLS file.
The collection header chunk in the DLS file format has the following structure.
|Byte sequence description||Length in bytes||Starts at byte in the chunk||Value|
|chunk ID||4||0x00||The ASCII character string "dlsd"|
|size||4||0x04||The size of the chunk in number of bytes (unsigned integer) less 8 (less the size of "chunk ID" and the "size"). The size of this chunk is always 4.|
|number of instruments||4||0x08||The number of instruments defined in the DLS file (unsigned integer).|
The instruments themselves are defined in a separate chunk of type LIST and subtype "lins" (an instrument list chunk). The number of instruments specified in this collection header chunk should match the actual number of instruments in the instrument list chunk.
Downloadable Sounds (DLS) format