Version of the interface the hal implements. Note that this relates to legacy HAL API versions since HIDL APIs are versioned using other mechanisms. There should be one section per audio HW module present on the platform. Each contains two mandatory tags: “halVersion” and “name”. The module "name" is the same as in previous .conf file. Each module must contain the following sections: - : a list of device descriptors for all input and output devices accessible via this module. This contains both permanently attached devices and removable devices. - : listing all output and input streams exposed by the audio HAL - : list of possible connections between input and output devices or between stream and devices. A is defined by a set of 3 attributes: -"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 this route - : permanently attached devices. The attachedDevices section is a list of devices names. Their names correspond to device names defined in "devicePorts" section. - is the device to be used when no policy rule applies The flags indicate suggested stream attributes supported by the profile. When choosing the mixPort of an audio track, the audioPolicy first considers the mixPorts with a preferredUsage including the track AudioUsage preferred . If non support the track format, the other mixPorts are considered. Eg: a will receive the audio of all apps playing with a MEDIA usage. It may receive audio from ALARM if there are no audio compatible . Audio usage specifies the intended use case for the sound being played. Please consult frameworks/base/media/java/android/media/AudioAttributes.java for the description of each value. Audio content type expresses the general category of the content. Please consult frameworks/base/media/java/android/media/AudioAttributes.java for the description of each value. Audio channel mask specifies presence of particular channels. There are two representations: - representation position (traditional discrete channel specification, e.g. "left", "right"); - indexed (this is similar to "tracks" in audio mixing, channels are represented using numbers). The default device will be used if multiple have the same type and no explicit route request exists for a specific device of that type. List all available sources for a given sink. Comma separated pair of number. The fist one is the framework level (between 0 and 100). The second one is the volume to send to the HAL. The framework will interpolate volumes not specified. Their MUST be at least 2 points specified. Audio stream type describing the intended use case of a stream. Please consult frameworks/base/media/java/android/media/AudioSystem.java for the description of each value. An audio source defines the intended use case for the sound being recorded. Please consult frameworks/base/media/java/android/media/MediaRecorder.java for the description of each value. Volume section defines a volume curve for a given use case and device category. It contains a list of points of this curve expressing the attenuation in Millibels for a given volume index from 0 to 100. 0,-9600 100,0 It may also reference a reference/@name to avoid duplicating curves. 0,-9600 100,0 Surround Sound section provides configuration related to handling of multi-channel formats.