atom feed8 messages in org.freebsd.freebsd-multimediaAudio driver template
FromSent OnAttachments
Christopher DavisJul 9, 2007 7:13 pm 
Hans Petter SelaskyJul 9, 2007 8:38 pm 
John-Mark GurneyJul 10, 2007 2:09 am 
Alexander LeidingerJul 10, 2007 8:08 am 
Yuriy TsibizovJul 10, 2007 1:20 pm 
John BaldwinJul 10, 2007 9:21 pm 
Christopher DavisJul 11, 2007 4:26 am 
Christopher DavisJul 13, 2007 5:11 am 
Subject:Audio driver template
From:Hans Petter Selasky (hsel@c2i.net)
Date:Jul 9, 2007 8:38:59 pm
List:org.freebsd.freebsd-multimedia

On Monday 09 July 2007 20:47, Christopher Davis wrote:

http://people.freebsd.org/~cg/template.c

Thought I would take a look at the audio driver template as part of my task to modernize drivers, soc2007. I would simplify the read and write functions to avoid using the bus tag and handle, but I'm not sure what else to do to bring it up to date.

How else can it be improved?

Regarding echo cancelling, you should add some code that time-stamps the audio data, and computes the current number of bytes in the RX/TX FIFOs!

Look at the exported functions in the Echo Canceller for I4B:

http://www.turbocat.net/~hselasky/isdn4bsd/sources/src/sys/i4b/layer1/i4b_echo_cancel.c

The echo canceller above is a work in progress.

--HPS