etc/audio_policy_configuration.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!-- Copyright (C) 2019 The Android Open Source Project

     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.
     You may obtain a copy of the License at

          http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing, software
     distributed under the License is distributed on an "AS IS" BASIS,
     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     See the License for the specific language governing permissions and
     limitations under the License.
-->

<audioPolicyConfiguration version="1.0" xmlns:xi="http://www.w3.org/2001/XInclude">
    <!-- version section contains a “version” tag in the form “major.minor” e.g version=”1.0” -->

    <!-- Global configuration Decalaration -->
    <globalConfiguration speaker_drc_enabled="true"/>


    <!-- Modules section:
        There is one section per audio HW module present on the platform.
        Each module section will contains two mandatory tags for audio HAL “halVersion” and “name”.
        The module names are the same as in current .conf file:
                “primary”, “A2DP”, “remote_submix”, “USB”
        Each module will contain the following sections:
        “devicePorts”: a list of device descriptors for all input and output devices accessible via this
        module.
        This contains both permanently attached devices and removable devices.
        “mixPorts”: listing all output and input streams exposed by the audio HAL
        “routes”: list of possible connections between input and output devices or between stream and
        devices.
            "route": is defined by an attribute:
                -"type": <mux|mix> means all sources are mutual exclusive (mux) or can be mixed (mix)
                -"sink": the sink involved in this route
                -"sources": all the sources than can be connected to the sink via vis route
        “attachedDevices”: permanently attached devices.
        The attachedDevices section is a list of devices names. The names correspond to device names
        defined in <devicePorts> section.
        “defaultOutputDevice”: device to be used by default when no policy rule applies
    -->
    <modules>
        <!-- Primary Audio HAL -->
        <module name="primary" halVersion="3.0">
            <attachedDevices>
                <item>Speaker</item>
                <item>Built-In Mic</item>
                <item>Echo Reference</item>
            </attachedDevices>
            <defaultOutputDevice>Speaker</defaultOutputDevice>
            <mixPorts>
                <mixPort name="primary output" role="source" flags="AUDIO_OUTPUT_FLAG_PRIMARY">
                    <profile name="" format="AUDIO_FORMAT_PCM_16_BIT"
                             samplingRates="48000" channelMasks="AUDIO_CHANNEL_OUT_STEREO"/>
                </mixPort>
                <mixPort name="primary input" role="sink">
                    <profile name="" format="AUDIO_FORMAT_PCM_16_BIT"
                             samplingRates="8000,11025,12000,16000,22050,24000,32000,44100,48000"
                             channelMasks="AUDIO_CHANNEL_IN_MONO"/>
                </mixPort>
                <mixPort name="echo reference" role="sink">
                    <profile name="echo_reference" format="AUDIO_FORMAT_PCM_32_BIT"
                             samplingRates="48000"
                             channelMasks="AUDIO_CHANNEL_IN_STEREO"/>
                </mixPort>
            </mixPorts>
            <devicePorts>
                <!-- Output devices declaration, i.e. Sink DEVICE PORT -->
                <devicePort tagName="Speaker" role="sink" type="AUDIO_DEVICE_OUT_SPEAKER" address="">
                    <profile name="" format="AUDIO_FORMAT_PCM_16_BIT"
                             samplingRates="48000" channelMasks="AUDIO_CHANNEL_OUT_STEREO"/>
                </devicePort>
                <devicePort tagName="Wired Headset" type="AUDIO_DEVICE_OUT_WIRED_HEADSET" role="sink">
                </devicePort>
                <devicePort tagName="Wired Headphones" type="AUDIO_DEVICE_OUT_WIRED_HEADPHONE" role="sink">
                </devicePort>
                <devicePort tagName="BT SCO" type="AUDIO_DEVICE_OUT_BLUETOOTH_SCO" role="sink">
                </devicePort>
                <devicePort tagName="BT SCO Headset" type="AUDIO_DEVICE_OUT_BLUETOOTH_SCO_HEADSET" role="sink">
                </devicePort>

                <devicePort tagName="Built-In Mic" type="AUDIO_DEVICE_IN_BUILTIN_MIC" role="source">
                </devicePort>
                <devicePort tagName="Wired Headset Mic" type="AUDIO_DEVICE_IN_WIRED_HEADSET" role="source">
                </devicePort>
                <devicePort tagName="BT SCO Headset Mic" type="AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET" role="source">
                </devicePort>
                <devicePort tagName="Echo Reference" type="AUDIO_DEVICE_IN_ECHO_REFERENCE" role="source">
                    <profile name="echo_reference" format="AUDIO_FORMAT_PCM_32_BIT"
                             samplingRates="48000"
                             channelMasks="AUDIO_CHANNEL_IN_STEREO"/>
                </devicePort>
            </devicePorts>
            <!-- route declaration, i.e. list all available sources for a given sink -->
            <routes>
                <route type="mix" sink="Speaker"
                       sources="primary output"/>
                <route type="mix" sink="Wired Headset"
                       sources="primary output"/>
                <route type="mix" sink="Wired Headphones"
                       sources="primary output"/>
                <route type="mix" sink="BT SCO"
                       sources="primary output"/>
                <route type="mix" sink="BT SCO Headset"
                       sources="primary output"/>
                <route type="mix" sink="primary input"
                       sources="Built-In Mic,Wired Headset Mic,BT SCO Headset Mic"/>
                <route type="mix" sink="echo reference"
                       sources="Echo Reference"/>
            </routes>

        </module>

        <!-- Usb Audio HAL -->
        <xi:include href="usb_audio_policy_configuration.xml"/>

        <!-- Remote Submix Audio HAL -->
        <xi:include href="r_submix_audio_policy_configuration.xml"/>

        <!-- Bluetooth Audio HAL -->
        <xi:include href="bluetooth_audio_policy_configuration.xml"/>

    </modules>
    <!-- End of Modules section -->

    <!-- Volume section -->

    <xi:include href="audio_policy_volumes.xml"/>
    <xi:include href="default_volume_tables.xml"/>

    <!-- End of Volume section -->

</audioPolicyConfiguration>