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      1 page.title=Audio
      2 pdk.version=1.0
      3 doc.type=porting
      4 @jd:body
      5 
      6 <div id="qv-wrapper">
      7 <div id="qv">
      8 <h2>In this document</h2>
      9 <a name="toc"/>
     10 <ul>
     11 <li><a href="#androidAudioBuildingDriver">Building an Audio Library</a></li>
     12 <li><a href="#androidAudioInterface">Interface</a></li>
     13 </ul>
     14 </div>
     15 </div>
     16 
     17 
     18 <p>AudioHardwareInterface serves as the glue between proprietary audio drivers and the Android AudioFlinger service, the core audio service that handles all audio-related requests from applications.</p>
     19 <p><img src="images/android_audio_architecture.gif"></p>
     20 
     21 Solid elements represent Android blocks and dashed elements represent partner-specific blocks.
     22 
     23 
     24 
     25 <a name="androidAudioBuildingDriver"></a><h3>Building an Audio Library</h3>
     26 
     27 <p>To implement an audio driver, create a shared library that implements the interface defined in <code>AudioHardwareInterface.h</code>. You must name your shared library <code>libaudio.so</code> so that it will get loaded from <code>/system/lib</code> at runtime.  Place libaudio sources and <code>Android.mk</code> in <code>vendor/acme/chipset_or_board/libaudio/</code>.</p>
     28 <p>The following stub <code>Android.mk</code> file ensures that <code>libaudio</code> compiles and links to the appropriate libraries:</p>
     29 
     30 <pre class="prettify">
     31 LOCAL_PATH := $(call my-dir)
     32 include $(CLEAR_VARS)
     33 
     34 LOCAL_MODULE := libaudio
     35 
     36 LOCAL_SHARED_LIBRARIES := \
     37     libcutils \
     38     libutils \
     39     libmedia \
     40     libhardware
     41 
     42 LOCAL_SRC_FILES += MyAudioHardware.cpp
     43 
     44 LOCAL_CFLAGS +=
     45 
     46 LOCAL_C_INCLUDES +=
     47 
     48 LOCAL_STATIC_LIBRARIES += libaudiointerface
     49 
     50 include $(BUILD_SHARED_LIBRARY)
     51 </pre>
     52 
     53 
     54 <a name="androidAudioInterface"></a><h3>Interface</h3>
     55 
     56 
     57 
     58 <p class="note"><strong>Note</strong>: This document relies on some Doxygen-generated content that appears in an iFrame below. To return to the Doxygen default content for this page, <a href="audio_sub_system.html">click here</a>.</p>
     59 
     60 
     61 <iframe onLoad="resizeDoxFrameHeight();" src="AudioHardwareInterface_8h.html" scrolling="no" scroll="no" id="doxygen" marginwidth="0" marginheight="0" frameborder="0" style="width:100%;"></iframe>
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