| David Warren | 5f6ca4f | 2009-04-30 17:11:58 -0700 | [diff] [blame^] | 1 | page.title=Audio |
| 2 | pdk.version=1.0 |
| 3 | @jd:body |
| 4 | |
| 5 | <a name="toc"/> |
| 6 | <div style="padding:10px"> |
| 7 | <a href="#androidAudioSubSystemIntroduction">Introduction</a><br/> |
| 8 | <a href="#androidAudioBuildingDriver">Building an Audio Library</a><br/> |
| 9 | <a href="#androidAudioInterface">Interface</a><br/></div></font> |
| 10 | |
| 11 | <a name="androidAudioSubSystemIntroduction"></a><h2>Introduction</h2> |
| 12 | |
| 13 | <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> |
| 14 | <p><img src="images/android_audio_architecture.gif"></p> |
| 15 | |
| 16 | Solid elements represent Android blocks and dashed elements represent partner-specific blocks. |
| 17 | |
| 18 | |
| 19 | |
| 20 | <a name="androidAudioBuildingDriver"></a><h2>Building an Audio Library</h2> |
| 21 | |
| 22 | <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> |
| 23 | <p>The following stub <code>Android.mk</code> file ensures that <code>libaudio</code> compiles and links to the appropriate libraries:</p> |
| 24 | |
| 25 | <pre class="prettify"> |
| 26 | LOCAL_PATH := $(call my-dir) |
| 27 | include $(CLEAR_VARS) |
| 28 | |
| 29 | LOCAL_MODULE := libaudio |
| 30 | |
| 31 | LOCAL_SHARED_LIBRARIES := \ |
| 32 | libcutils \ |
| 33 | libutils \ |
| 34 | libmedia \ |
| 35 | libhardware |
| 36 | |
| 37 | LOCAL_SRC_FILES += MyAudioHardware.cpp |
| 38 | |
| 39 | LOCAL_CFLAGS += |
| 40 | |
| 41 | LOCAL_C_INCLUDES += |
| 42 | |
| 43 | LOCAL_STATIC_LIBRARIES += libaudiointerface |
| 44 | |
| 45 | include $(BUILD_SHARED_LIBRARY) |
| 46 | </pre> |
| 47 | |
| 48 | |
| 49 | <a name="androidAudioInterface"></a><h2>Interface</h2> |
| 50 | |
| 51 | |
| 52 | |
| 53 | <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> |
| 54 | |
| 55 | |
| 56 | <iframe onLoad="resizeDoxFrameHeight();" src="AudioHardwareInterface_8h.html" scrolling="no" scroll="no" id="doxygen" marginwidth="0" marginheight="0" frameborder="0" style="width:100%;"></iframe> |