Starting March 27, 2025, we recommend using android-latest-release instead of aosp-main to build and contribute to AOSP. For more information, see Changes to AOSP.
Configure a shared library
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After creating an
audio policy
configuration, you must package the HAL implementation into a shared library
and copy it to the appropriate location:
- Create a
device/<company>/<device>/audio
directory to contain your library's source files.
- Create an
Android.mk file to build the shared library. Ensure
the Makefile contains the following line:
LOCAL_MODULE := audio.primary.<device>
Your library must be named audio.primary.<device>.so
so Android can correctly load the library. The primary portion of
this filename indicates that this shared library is for the primary audio
hardware located on the device. The module names
audio.a2dp.<device> and
audio.usb.<device> are also available for Bluetooth and
USB audio interfaces. Here is an example of an Android.mk from the
Galaxy Nexus audio hardware:
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)
- 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
device/<company>/<device>/device.mk
Makefile:
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 \
- Copy the audio policy configuration file you created earlier to the
system/etc/ directory in your product's
device/<company>/<device>/device.mk Makefile.
For example:
PRODUCT_COPY_FILES += \
device/samsung/tuna/audio/audio_policy.conf:system/etc/audio_policy.conf
- Declare the shared modules of your audio HAL that are required by your
product in the product's
device/<company>/<device>/device.mk Makefile.
For example, the Galaxy Nexus requires the primary and Bluetooth audio HAL
modules:
PRODUCT_PACKAGES += \
audio.primary.tuna \
audio.a2dp.default
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Last updated 2024-08-26 UTC.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2024-08-26 UTC."],[],[],null,["# Configure a shared library\n\nAfter creating an\n[audio policy\nconfiguration](/docs/core/audio/implement-policy), you must package the HAL implementation into a shared library\nand copy it to the appropriate location:\n\n1. Create a `device/\u003ccompany\u003e/\u003cdevice\u003e/audio` directory to contain your library's source files.\n2. Create an `Android.mk` file to build the shared library. Ensure the Makefile contains the following line: \n\n ```\n LOCAL_MODULE := audio.primary.\u003cdevice\u003e\n ```\n\n Your library must be named `audio.primary.\u003cdevice\u003e.so`\n so Android can correctly load the library. The `primary` portion of\n this filename indicates that this shared library is for the primary audio\n hardware located on the device. The module names\n `audio.a2dp.\u003cdevice\u003e` and\n `audio.usb.\u003cdevice\u003e` are also available for Bluetooth and\n USB audio interfaces. Here is an example of an `Android.mk` from the\n Galaxy Nexus audio hardware: \n\n ```\n LOCAL_PATH := $(call my-dir)\n\n include $(CLEAR_VARS)\n\n LOCAL_MODULE := audio.primary.tuna\n LOCAL_MODULE_RELATIVE_PATH := hw\n LOCAL_SRC_FILES := audio_hw.c ril_interface.c\n LOCAL_C_INCLUDES += \\\n external/tinyalsa/include \\\n $(call include-path-for, audio-utils) \\\n $(call include-path-for, audio-effects)\n LOCAL_SHARED_LIBRARIES := liblog libcutils libtinyalsa libaudioutils libdl\n LOCAL_MODULE_TAGS := optional\n\n include $(BUILD_SHARED_LIBRARY)\n ```\n\n3. 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 `device/\u003ccompany\u003e/\u003cdevice\u003e/device.mk` Makefile: \n\n ```\n PRODUCT_COPY_FILES := ...\n\n PRODUCT_COPY_FILES += \\\n frameworks/native/data/etc/android.hardware.audio.low_latency.xml:system/etc/permissions/android.hardware.audio.low_latency.xml \\\n ```\n\n4. Copy the audio policy configuration file you created earlier to the `system/etc/` directory in your product's `device/\u003ccompany\u003e/\u003cdevice\u003e/device.mk` Makefile. For example: \n\n ```\n PRODUCT_COPY_FILES += \\\n device/samsung/tuna/audio/audio_policy.conf:system/etc/audio_policy.conf\n ```\n\n5. Declare the shared modules of your audio HAL that are required by your product in the product's `device/\u003ccompany\u003e/\u003cdevice\u003e/device.mk` Makefile. For example, the Galaxy Nexus requires the primary and Bluetooth audio HAL modules: \n\n ```\n PRODUCT_PACKAGES += \\\n audio.primary.tuna \\\n audio.a2dp.default\n ```"]]
