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gerrit-public.fairphone.software / fp2-dev / platform / development / e943f2fd8e7623ba3ea12bb65294d30446db4174 / . / pdk / docs / audio_sub_system.html
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]5<title>Android - Porting Guide</title>
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]48
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]89
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]90 <h1>Android Platform Development Kit</h1>
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]95
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]96 <li> <a href="http://android-developers.blogspot.com/" title="Official Android blog">Blog</a> </li>
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]99 <li> <a href="mailto:android-pdk-feedback@google.com?subject=PDK%20Feedback&body=(filed%20from:%20audio_sub_system.html%20v0.6%20-%2025%20November%202008)%0D%0A%0D%0ASUMMARY:%0D%0A%0D%0A%0D%0A%0D%0ASTEPS%20TO%20REPRODUCE:%0D%0A%0D%0A%0D%0A%0D%0AADDITIONAL%20NOTES:">Report a Problem</a> </li>
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The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]101 </ul>
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]112
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]113 <ul>
114 <li><a href="system_requirements.html">Device Requirements</a></li>
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The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]119 <li><a href="build_system.html">Build System</a></li>
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]123
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]131
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]132 <li> <strong>Multimedia</strong>
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]134 <li><a href="audio_sub_system.html">Audio</a></li>
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The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]136 </ul>
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]139
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The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]153 <li> <strong>Telephony</strong>
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155 <li><a href="telephony.html">Radio Interface Layer</a></li>
The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]156
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]157 </ul>
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The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]161 <li><a href="instrumentation_testing.html">Instrumentation Testing</a></li>
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The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]175<a name="androidAudioSubSystemTitle"></a><h1>Audio</h1>
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]176
177
178
179<a name="toc"/>
180<div style="padding:10px">
181<a href="#androidAudioSubSystemIntroduction">Introduction</a><br/>
The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]182<a href="#androidAudioBuildingDriver">Building an Audio Library</a><br/>
183<a href="#androidAudioInterface">Interface</a><br/></div></font></div>
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]184
185<a name="androidAudioSubSystemIntroduction"></a><h2>Introduction</h2>
186
The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]187<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>
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]188<p><img src="android_audio_architecture.gif"></p>
189
The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]190Solid elements represent Android blocks and dashed elements represent partner-specific blocks.
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]191
192
193
The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]194<a name="androidAudioBuildingDriver"></a><h2>Building an Audio Library</h2>
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]195
The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]196<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>partner/acme/chipset_or_board/libaudio/</code>.</p>
197<p>The following stub <code>Android.mk</code> file ensures that <code>libaudio</code> compiles and links to the appropriate libraries:</p>
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]198
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]199<pre class="prettify">
The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]200LOCAL_PATH := $(call my-dir)
201include $(CLEAR_VARS)
202
203LOCAL_MODULE := libaudio
204
205LOCAL_SHARED_LIBRARIES := \
206 libcutils \
207 libutils \
208 libmedia \
209 libhardware
210
211LOCAL_SRC_FILES += MyAudioHardware.cpp
212
213LOCAL_CFLAGS +=
214
215LOCAL_C_INCLUDES +=
216
217LOCAL_STATIC_LIBRARIES += libaudiointerface
218
219include $(BUILD_SHARED_LIBRARY)
The Android Open Source Project5c118522008-10-21 07:00:00 -0700[diff] [blame]220</pre>
221
222
The Android Open Source Projecte943f2f2008-12-17 18:04:04 -0800[diff] [blame^]223<a name="androidAudioInterface"></a><h2>Interface</h2>
224
225
226
227<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>
228
229
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