Google Custom Components Architecture

This directory houses components specific to Google integrations, such as specialized wake-word or hotword engines.

Configuration and Scripts

• Kconfig: Exposes menus for Google components, including COMP_GOOGLE_HOTWORD_DETECT (engine for hotword detection), COMP_GOOGLE_RTC_AUDIO_PROCESSING (acoustic echo cancellation with tunable memory size, sample rates, max channels, and reference max channels), and COMP_GOOGLE_CTC_AUDIO_PROCESSING (crosstalk cancellation). It also exposes mock definitions for CI testing (COMP_STUBS).
• CMakeLists.txt: Conditionally links external static libraries (libhifi3_google_hotword_dsp_api.a, google_rtc_audio_processing, google_ctc_audio_processing) from third_party tools. Defines Zephyr and non-Zephyr build pipelines.
• google_rtc_audio_processing.toml / google_ctc_audio_processing.toml: Specify topology module configurations for RTC_AEC and CTC models respectively with pinning mappings (like DMIC pins and playback references).
• Topology (.conf): Incorporates tools/topology/topology2/include/components/ctc.conf (defaults to UUID bc:1b:0e:bf:6a:dc:fe:45:bc:90:25:54:cb:13:7a:b4) and google-rtc-aec.conf (defaults to UUID a6:a0:80:b7:9f:26:6f:46:b4:77:23:df:a0:5a:f7:58) with strict audio format channel maps (e.g. 2ch vs 4ch mappings).