[companion-discuss] SUN's AU Format

[Bart Smaalders]

Pauline Yeo wrote:
> I am looking for information regarding a Audio format - "AU" which was introduced by Sun Microsystems.  I have fill up to Sun's on line Contact Form but still couldn't get to the appropriate contact person to response to my queries.
> Am actually looking for licensing information on behalf of my company, we have new Internet Radio project where the device supports the AU format. We would like to know if AU format is an open source which do not need license to be used or there is royalty fees we need to pay in order to use it to our product. Hopefully I have found the correct forum to my question.
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This isn't the right place, but I think I can answer your question...

 From the audio man page:

  Encodings
      An encoding parameter specifies the audio  data  representa-
      tion. u-Law encoding corresponds to  CCITT G.711, and is the
      standard for voice data used by telephone companies  in  the
      United  States,  Canada,  and  Japan. A-Law encoding is also
      part of  CCITT  G.711  and  is  the  standard  encoding  for
      telephony elsewhere in the world. A-Law and u-Law audio data
      are sampled at a rate of 8000 samples per second with 12-bit
      precision,  with  the data compressed to 8-bit samples.  The
      resulting audio data quality is equivalent to that of  stan-
      dard analog telephone service.

There are no license requirements.

Here's some handy documentation on the file format:

http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/AU/AU.html

Sun used 8Khz u-law encoded files in the SparcStation 1 in 1989.

=- Bart


-- 
Bart Smaalders			Solaris Kernel Performance
barts at cyber.eng.sun.com		http://blogs.sun.com/barts