28 Dec
2010
28 Dec
'10
4:28 p.m.
On Tue, Dec 28, 2010 at 10:00 AM, Basavaraj Hiremath <hraj50(a)yahoo.com>wrote;wrote:
Hi,
I have implemented/ported USB device driver on the custom platform(ARM
processor).
I am trying to read and write audio data through to USB headphone.
These are my questions?
1) USB isochronous read is an asynchronous call, how can I read data from
the mic and send immediatly to speaker(just to make echo),
2) How much data needs to be read from the mic and send to speaker without
loosing audio quality?(is it every frames (1msec data) or more buffering can
be done)
Basically, how can I read from mic and send to speaker continuously without
loosing data?
this is all basic ALSA programming that has nothing specifically to do with
USB. i suggest you read a few basic ALSA programming tutorials. although i
don't think that mine is particularly good, its easy to find online. a
google search for
alsa programming tutorial
will provide several useful links.