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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)

• Overview design
• Usage of a bluetooth headset with Android BT stack only
• Microhpone from Headset, audio on External Loudspeakers
• No Bluetooth, both Microhpone and Loudspeakers are used for telephony example such as skype or any other

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

Offloading (encoded,...) 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

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 multichannles 5.1 audio from Netflix (any DRM issues)