X-Face

Revision as of 20:42, 16 June 2016

X-Face is a compressed image format that can be placed in an email or Usenet newsgroup message header. It is expected to contain the sender's picture or avatar. It is a 48×48 bi-level image. The format appears to be fairly complex.

Discussion

Although X-Face data is often expected to be stored in a file, there isn't really a standard X-Face file format. The main thing to be aware of is that sometimes the "X-Face:" header name is stored in the file, and sometimes it is not. Different software has different requirements.

File extensions .face and .xface have both been suggested. Sometimes, X-Face data will be in a file named ".face" in the user's home directory.

Although a fair number of open source programs support the format, we have not been able to locate any specifications whatsoever. Most or all X-Face code is based on James Ashton's compface software, and compface's code is fairly opaque.

compface format

The compface software by default converts X-Face to and from a custom format, which it describes as "48 lines each of 3 sixteen bit hexadecimal integers, comma terminated in C initialiser style." It looks something like this:

0x0000,0x0000,0x0000,
0x0000,0x4400,0x0000,
0x0000,0x7600,0x0000,
0x0002,0x6B80,0x0100,
0x0006,0x0440,0x0600,
0x0008,0x0040,0x0E00,
...

Figuring out the byte-order and bit-order is left as an exercise for the reader.

Software

• compface-1.4.tar.gz (uncompface -X to convert to XBM format)
• FFmpeg

Samples

• faces man page, "XFACE SUPPORT" section, has an example.

Links

• Faces Archive - Lists some X-Face resources
• faces man page
• Online X-Face Converter
• Wikipedia: X-Face