Format details

Note:

    Multi-byte integers are little-endian.
    Some Squeeze software limits the length of a Huffman code to at most 16 bits. 

File structure
Field 	Size in bytes 	Description
signature 	2 	0x76 0xff
checksum 	2 	Low 16 bits of the sum of the decompressed byte values.
filename 	variable 	Original filename, terminated by a NUL byte. (TODO: Find a specification for this field. Some software interprets it in the same way as Crunch, but that might be overkill.)
compressed data 	variable 	See below.
timestamp extension 	8 	Optional timestamp. See below.
Compressed data section

The "compressed data" section. This part is equivalent to ARC compression method 4.
Field 	Size in bytes 	Description
node_count 	2 	Number of nodes in the table. Valid values are 0 through 256, inclusive.
node table 	4 × node_count 	The encoded Huffman tree. See below.
data 	variable 	Huffman-encoded data. Least-significant bit first. After Huffman decoding, the data is RLE90-compressed. The data should end with a special "stop" code. However, this compression format could be used in situations where it could also be terminated by other means.

A table node contains two encoded values. Each is a signed 16-bit integer interpreted as follows:
Encoded value 	Meaning
−257 	Stop
−256 ... −1 	Byte value 255 ... 0
0 ... 255 	Pointer to a child node
Timestamp extension

Format of timestamp extension, taken from SQDATE.DOC (see below). It starts at the first byte boundary after the Stop code. It is present if the signature and checksum are correct.
Field 	Size in bytes 	Description
signature 	2 	0xff77 (0x77 0xff)
date 	2 	MS-DOS date/time format
time 	2
checksum 	2 	Low 16 bits of the sum of the first three fields, interpreted as little-endian integers.
Identification

Files begin with bytes 76 ff.

Note that this does not distinguish them from CODEC (Telvox).