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| <head> |
| <title>Configuring a Shared Library</title> |
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| |
| |
| |
| <p>After creating an |
| <a href="/devices/audio/implement-policy.html">audio policy |
| configuration</a>, you must package the HAL implementation into a shared library |
| and copy it to the appropriate location:</p> |
| |
| <ol> |
| <li>Create a <code>device/<company>/<device>/audio</code> |
| directory to contain your library's source files.</li> |
| <li>Create an <code>Android.mk</code> file to build the shared library. Ensure |
| the Makefile contains the following line: |
| <br> |
| <pre class="devsite-click-to-copy"> |
| LOCAL_MODULE := audio.primary.<device> |
| </pre> |
| <br> |
| <p>Your library must be named <code>audio.primary.<device>.so</code> |
| so Android can correctly load the library. The <code>primary</code> portion of |
| this filename indicates that this shared library is for the primary audio |
| hardware located on the device. The module names |
| <code>audio.a2dp.<device></code> and |
| <code>audio.usb.<device></code> are also available for Bluetooth and |
| USB audio interfaces. Here is an example of an <code>Android.mk</code> from the |
| Galaxy Nexus audio hardware:</p> |
| |
| <pre class="devsite-click-to-copy"> |
| LOCAL_PATH := $(call my-dir) |
| |
| include $(CLEAR_VARS) |
| |
| LOCAL_MODULE := audio.primary.tuna |
| LOCAL_MODULE_RELATIVE_PATH := hw |
| LOCAL_SRC_FILES := audio_hw.c ril_interface.c |
| LOCAL_C_INCLUDES += \ |
| external/tinyalsa/include \ |
| $(call include-path-for, audio-utils) \ |
| $(call include-path-for, audio-effects) |
| LOCAL_SHARED_LIBRARIES := liblog libcutils libtinyalsa libaudioutils libdl |
| LOCAL_MODULE_TAGS := optional |
| |
| include $(BUILD_SHARED_LIBRARY) |
| </pre> |
| </li> |
| <br> |
| <li>If your product supports low latency audio as specified by the Android CDD, |
| copy the corresponding XML feature file into your product. For example, in your |
| product's <code>device/<company>/<device>/device.mk</code> |
| Makefile: |
| <pre class="devsite-click-to-copy"> |
| PRODUCT_COPY_FILES := ... |
| |
| PRODUCT_COPY_FILES += \ |
| frameworks/native/data/etc/android.hardware.audio.low_latency.xml:system/etc/permissions/android.hardware.audio.low_latency.xml \ |
| </pre> |
| </li> |
| <br> |
| <li>Copy the audio policy configuration file you created earlier to the |
| <code>system/etc/</code> directory in your product's |
| <code>device/<company>/<device>/device.mk</code> Makefile. |
| For example: |
| <pre class="devsite-click-to-copy"> |
| PRODUCT_COPY_FILES += \ |
| device/samsung/tuna/audio/audio_policy.conf:system/etc/audio_policy.conf |
| </pre> |
| </li> |
| <br> |
| <li>Declare the shared modules of your audio HAL that are required by your |
| product in the product's |
| <code>device/<company>/<device>/device.mk</code> Makefile. |
| For example, the Galaxy Nexus requires the primary and Bluetooth audio HAL |
| modules: |
| <pre class="devsite-click-to-copy"> |
| PRODUCT_PACKAGES += \ |
| audio.primary.tuna \ |
| audio.a2dp.default |
| </pre> |
| </li> |
| </ol> |
| |
| </body> |
| </html> |
