JUKEBOX.SI

JUKEBOX.SI is an SI file containing 60 audio tracks of music and radio dialogue. With a few exceptions^{[citation needed]}, all of Lego Island's music is stored in JUKEBOX.SI.

Technical Information

All audio in JUKEBOX.SI is uncompressed mono PCM. Most of the tracks are in 11025 Hz and 16-bit, but a handful are 22050 Hz and 8-bit. Each track starts with a header specifying its format.

Due to SI files' standardization with RIFF, each track's header (containing information about the sample rate, format, etc.) can be transplanted directly into a WAV file, however due to their chunked/interleaved nature, the PCM data cannot be directly transplanted without noticeable clicks and glitches in the output.

Music appears to begin with a MxDa and is split into chunks of MxCh. The MxDa header contains information about the PCM audio in the MxCh chunks. The first MxCh appears to be information about the remainder of the chunks in the MxDa structure.

All bytes are little endian.

MxDa Header Specification

Bytes	Offset	Description
MxDa	0	Identifier
MxCh	4	Chunk Header
Chunk Size	8	4-byte Integer
Sub-Chunk Size	22	4-byte Integer - The remaining size of this chunk after this value
Audio Format	26	2-byte Integer - 1 = PCM, others indicate some form of compression
Number of Channels	28	2-byte Integer - 1 = Mono, 2 = Stereo
Sample Rate	30	4-byte Integer
Byte Rate	34	4-byte Integer - is equal to Sample Rate * Number of Channels * BitsPerSample/8
Bytes per Sample	36	2-byte Integer - is equal to Number of Channels * BitsPerSample/8
Bits per Sample per Channel	38	2-byte Integer - 8 = 8-bit, 16 = 16-bit, etc.

MxCh Specification

Bytes	Offset	Description
MxCh	0	Chunk Header
Chunk Size	4	4-byte Integer
Data	8	Arbitrary data no more than "Chunk Size" in bytes