Hexagon DSP processor allows activate your device while it’s on standby https://qualcomm.com/videos/snapdragon-voice-activation. Some Android devices support this feature, for example Google Pixel reacts to keyphrase "Ok Google". In the source code of the android, I found the code responsible for loading the keyphrase into the DSP processor (The Hexagon DSP processor is built into the Qualcomm processor):
https://android.googlesource.com/platform/hardware/libhardware/+/master/modules/soundtrigger/sound_trigger_hw.c https://android.googlesource.com/platform/system/media/+/master/audio/include/system/sound_trigger.h
The sound model description structure sound_trigger_sound_model pass in the method stdev_load_sound_model. Sound model structure:
/*
* Base sound model descriptor. This struct is the header of a larger block passed to
* load_sound_model() and containing the binary data of the sound model.
* Proprietary representation of users in binary data must match information indicated
* by users field
*/
struct sound_trigger_sound_model {
sound_trigger_sound_model_type_t type; /* model type. e.g. SOUND_MODEL_TYPE_KEYPHRASE */
sound_trigger_uuid_t uuid; /* unique sound model ID. */
sound_trigger_uuid_t vendor_uuid; /* unique vendor ID. Identifies the engine the
sound model was build for */
unsigned int data_size; /* size of opaque model data */
unsigned int data_offset; /* offset of opaque data start from head of struct
(e.g sizeof struct sound_trigger_sound_model) */
};
Does anyone know how to generate a binary data of the sound model or where to find information about it?
You can download the sound model for the keyphrase ''Ok Google" by link: https://drive.google.com/open?id=0B9jcQJRmjR0yaDJhOXN2M2ZLYm8. I loaded it into the DSP processor and it works.
Helpfull Android classes: https://android.googlesource.com/platform/frameworks/base/+/master/services/voiceinteraction/java/com/android/server/soundtrigger/SoundTriggerHelper.java https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/hardware/soundtrigger/SoundTriggerModule.java https://android.googlesource.com/platform/frameworks/base/+/master/core/jni/android_hardware_SoundTrigger.cpp https://android.googlesource.com/platform/frameworks/av/+/master/soundtrigger/SoundTrigger.cpp https://android.googlesource.com/platform/frameworks/av/+/master/soundtrigger/ISoundTrigger.cpp
