Description Of Work

curation of topics from : List of prioritized topics for the Audio HAL

PoC github repo : android-external-audio-mixing repository

hint about progress steps

define the related sw component affected by changes
define the interfaces (details discussed between those who change the components)
define which tasks require a real HW and which ones can be deployed on emulator (which part of the code is HW dependent)

#	Component - main topics	JIRA sub-items
raw streams	Raw Stream Extraction (multizone audio, etc.) todo: detail it + use case	Overview picture with SW components Audio HAL (open point: keep modified or rewrite it) Config for multizone Separate contexts for audio input PCM streams (open point: separation concept to be defined)
	Input and Control of external streams (microphone, or external player) todo: detail it + use case todo: be more explicit and clear about for example what is "external"	Design Overview (pointing to the actual sw comp) getting stream from Microphone (line in) config in AOSP external player or other device (BT or other)
13	Bluetooth Device Integration in Android System. As a user I have a BT headset (with speakers, microphone, control buttons, or even the car itself, etc.). I should be able to use it in an Android System.	Overview design Usage of a bluetooth headset with Android BT stack only Microphone from Headset, audio on External Loudspeakers No Bluetooth, both Microphone and Loudspeakers are used for telephony example such as skype or any other forward audio stream from external source (to connected BT device (speaker/headphone) via Android Audio subsystem
08	Ensure measurability of full audio path latency As a user I would not want my audio connection to be delayed. Each delay measure will be split in modules, which module brings which delay, eg (Bluetooth delay, mixing delay, routing delay,...)	Overview design components and APIs involved in the Audio path anti-jitter buffers configurations Total delay for Telephony on external speakers use case Total delay for Video streaming where audio plays on an external speaker add latency measurements means to quick audio solutions (AAudio)* investigate PCM transport impact on latency, check alternatives (currently named sockets are being used, alternative shared memory or pipes)
	Offloading to external speakers or loopback to Android. (offloading examples, codecs MPEG,MP3, DSPs, transport e.g. AVB)	Design Overview (pointing to the actual sw comp) Offloading part-1 (overview on concept, which APIs) Offloading part-2 (usage) Offloading with loopback to Android
09	Offloading use case : Forwarding Multi-Channel audio efficiency by keeping	PCM 5.1 sample audio Guidelines for specific policy config to prevent downmixing Example implementation playing multichannels 5.1 audio from Netflix (any DRM issues)

Milestones

#	Summary	Details Comments
1	running demo on real HW	compiling android-external-audio-mixing repository for selected target HW (Renesas-H3) optional support for 2nd HW (Low cost HiKey) TODO define functions to be included (input streams) At this stage, the function selection for Milestone 3 should be agreed upon
2	Full Audio Path on real HW	support of full audio path Raw streams extraction input external streams control of an external stream demo should showcase at least one function
3	Selected Functions partitioned on HW	All selected and prioritized functions running on the main target HW

Description Of Work

Raw Stream Extraction

Input and Control of external streams

As a user I have a BT headset (with speakers, microphone, control buttons, or even the car itself, etc.). I should be able to use it in an Android System.

Ensure measurability of full audio path latency

Offloading to external speakers or loopback to Android.

Offloading use case : Forwarding Multi-Channel audio

Milestones