1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4<META http-equiv="Content-Type" content="text/html; charset=windows-1252"> 5<META name="GENERATOR" content="Microsoft FrontPage 5.0"> 6<META http-equiv="Content-Style-Type" content="text/css"> 7<LINK rel="stylesheet" type="text/css" href="../../CSS/revolution.css"> 8<TITLE>AX Stream</TITLE> 9</HEAD> 10<BODY> 11<H1 align="left">axstream</H1> 12 13<H2>Description</H2> 14<p>This program demonstrates "software audio streaming". Audio data is streamed from disk into a buffer in external main memory (MEM2) and played through the DSP using an AX voice.</p> 15 16<p>AX voice plays the data in the buffer in looping mode (<code>addr.loopFlag=AXPBADDR_LOOP_ON</code>). The program implements streaming by continuously loading new audio data into buffer regions for which playback has completed.</p> 17 18<p>The audio data to play back is 16-bit PCM (<code>.pcm16</code>), 8-bit PCM (<code>.pcm8</code>), and ADPCM (<code>.dsp</code>). The method for specifying a buffer address is different for each data format. Decoding parameters must also be specified for ADPCM data. Be aware of data format differences.</p> 19 20<p>This program does not use <CODE>SRC</CODE> for AX because the sampling rate of all the audio data is 32 kHz. You must set <CODE>SRC</CODE> appropriately when using data that is not 32 kHz.</p> 21 22<p>The format of 16-bit PCM (<CODE>pcm16</CODE>) and 8-bit PCM (<CODE>pcm8</CODE>) are as follows.</p> 23<UL> 24<LI>16-bit PCM (<CODE>pcm16</CODE>): 16-bit PCM data, monaural, big-endian 25<LI> 8-bit PCM (<CODE>pcm8</CODE>): 8-bit PCM data, monaural 26</UL> 27<p> Both files have only audio data, and contain no other (for example, header) information.</p> 28 29<H2>Coverage</H2> 30<UL type="DISC"> 31<LI>AX initialization, setup, shutdown 32<LI>AX voice allocation, runtime manipulation 33<LI>MIX initialization, setup, shutdown 34<LI>MIX runtime manipulation 35</UL> 36 37<H2>Using the Demo</H2> 38<TABLE border="0" width="615"> 39 <TBODY> 40 <TR> 41<TD width="149">A Button</TD> 42<TD width="458">Performs streaming playback of 16-bit PCM data.</TD> 43 </TR> 44 <TR> 45<TD width="149">B Button</TD> 46<TD width="458">Performs streaming playback of 8-bit PCM data.</TD> 47 </TR> 48 <TR> 49<TD width="149">X Button</TD> 50<TD width="458">Performs streaming playback of ADPCM data.</TD> 51 </TR> 52 <TR> 53<TD width="149">Y Button</TD> 54<TD width="458">Stops stream (to stop before starting another).</TD> 55 </TR> 56 <TR> 57<TD width="149">START/PAUSE</TD> 58<TD width="458">Exits program.</TD> 59 </TR> 60 </TBODY> 61</TABLE> 62 63<P>This program does not display any video. Instructions are printed to the serial output during runtime.</P> 64 65<H2>Required Data Files</H2> 66<UL type="DISC"> 67 <LI><CODE>//axdemo/stream/left.pcm16 </CODE> 68 <LI><CODE>//axdemo/stream/right.pcm16 </CODE> 69 <LI><CODE>//axdemo/stream/left.pcm8 </CODE> 70 <LI><CODE>//axdemo/stream/right.pcm8 </CODE> 71 <LI><CODE>//axdemo/stream/left.dsp </CODE> 72 <LI><CODE>//axdemo/stream/right.dsp </CODE> 73</UL> 74 75<H2>Revision History</H2> 76<P> 772007/09/03 Deleted a description related to ARAM. Added file descriptions.<br>2006/03/01 Initial version.<BR> 78</P> 79 80<hr><p>CONFIDENTIAL</p></body> 81</HTML>