<br><br><div class="gmail_quote">On Tue, Dec 28, 2010 at 10:00 AM, Basavaraj Hiremath <span dir="ltr"><<a href="mailto:hraj50@yahoo.com">hraj50@yahoo.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font: inherit;" valign="top">Hi,<div>I have implemented/ported USB device driver on the custom platform(ARM processor).</div><div>I am trying to read and write audio data through to USB headphone.</div>
<div>These are my questions?</div><div><br></div><div>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),</div><div><br></div><div>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)</div>
<div><br></div><div>Basically, how can I read from mic and send to speaker continuously without loosing data?</div></td></tr></tbody></table></blockquote><div><br>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 <br>
<br> alsa programming tutorial<br><br>will provide several useful links. <br><br><br></div></div>