<?xml version="1.0" encoding="UTF-8" ?>
<?xml-stylesheet type="text/xsl" href="https://community.arm.com/utility/feedstylesheets/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/"><channel><title>USB Audio class support for multiple audio streams</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/25172/usb-audio-class-support-for-multiple-audio-streams</link><description> 
Hello, 
Does USB audio device class for (LPC ARM based micros) support
multiple audio streams? 

 
I found USB speaker example but would like to implement microphone
input as well (headset scenario) for voice quality audio. 

 
Can anybody confirm that</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: USB Audio class support for multiple audio streams</title><link>https://community.arm.com/thread/55902?ContentTypeID=1</link><pubDate>Wed, 22 Apr 2009 03:03:33 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:a71220ef-7d70-4301-a109-7dfdcd0260ab</guid><dc:creator>Tsuneo Chinzei</dc:creator><description>&lt;p&gt;&lt;p&gt;
&lt;i&gt;&amp;gt; Does USB audio device class for (LPC ARM based micros)
support multiple audio streams?&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
Yes.&lt;br /&gt;
Each audio stream is assigned to dedicated AudioStreaming interface.
USB Audio supports multiple AudioStreaming interfaces.&lt;br /&gt;
You&amp;#39;ll see a typical example descriptors and detailed description in
the attached doc of this MS page.&lt;/p&gt;

&lt;p&gt;
&amp;quot;USB Handset Peripherals and Windows&amp;quot; on MS WHDC&lt;br /&gt;
&lt;a href="http://www.microsoft.com/whdc/connect/usb/usbtelephony.mspx"&gt;www.microsoft.com/.../usbtelephony.mspx&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;
USBtelephony-v091.doc&lt;br /&gt;

&lt;a href="http://download.microsoft.com/download/1/6/1/161ba512-40e2-4cc9-843a-923143f3456c/USBTelephony-v091.doc"&gt;download.microsoft.com/.../USBTelephony-v091.doc&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;
3 Descriptor Hierarchy&lt;br /&gt;
&lt;i&gt;This USB handset device includes an AudioControl interface (0),
two AudioStreaming interfaces (1 and 2 &amp;acirc;&amp;euro;&amp;quot; one for capture
and one for render), and a HID interface (3).&lt;/i&gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;i&gt;&amp;gt; I found USB speaker example but would like to implement
microphone input as well (headset scenario) for voice quality audio.
Can anybody confirm that is possible with Keil USB audio
library?&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
The requirement for this configuration is just two isoc endpoints
(and optional interrupt EP for HID), other than the default EP. Any
LPC USB MCU will do. If you are talking about one of these example,
you can extend them as you expected.&lt;/p&gt;

&lt;p&gt;
LPC2148 USB Audio Device Example&lt;br /&gt;
&lt;a href="http://www.keil.com/download/docs/308.asp"&gt;http://www.keil.com/download/docs/308.asp&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;
LPC2368 / LPC2378 USB Audio Device Example&lt;br /&gt;
&lt;a href="http://www.keil.com/download/docs/334.asp"&gt;http://www.keil.com/download/docs/334.asp&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;
Tsuneo&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>