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Vivox Core SDK

Smart Platform Audio Management

Understand how SPAM optimizes audio configurations.
Read time 1 minuteLast updated 20 hours ago
The Vivox SDK uses Smart Platform Audio Management (SPAM) to automatically select the optimal Android audio configuration based on the context. SPAM will optimize the audio configuration for voice if both of the following scenarios occur:
  • The client attempts to access the microphone (for example, when in a session)
  • The audio is rendered through the built-in speakerphone, or Bluetooth SCO
In all other scenarios, SPAM will optimize the audio configuration for general-purpose audio. SPAM configuration includes:
  • The Android AudioManager mode
    • When optimizing for voice, this is set to 
      MODE_IN_COMMUNICATION
      .
    • When optimizing for general-purpose audio, this is set to 
      MODE_NORMAL
      .
  • The OpenSL ES render stream and recording preset
    • In voice mode, the render stream is set to 
      SL_ANDROID_STREAM_VOICE
      and the recording preset is set to 
      SL_ANDROID_RECORDING_PRESET_VOICE_COMMUNICATION
      .
    • For general-purpose audio, the render stream is set to 
      SL_ANDROID_STREAM_MEDIA
      and the recording preset is set to 
      SL_ANDROID_RECORDING_PRESET_VOICE_RECOGNITION
      .
  • The Bluetooth profile
    • In voice mode, when using an audio Bluetooth device, SPAM will use Bluetooth SCO by default, if available. This ensures that the microphone on the Bluetooth device is used to provide the best voice experience for Vivox users.
    • When leaving voice mode, SPAM will automatically switch to A2DP and prioritize render audio quality over voice experience. This is configurable; you can change SPAM to always use A2DP by setting the 
      bluetooth_profile
      parameter on the SDK config struct.
SPAM also ensures that audio interruptions, such as phone calls, are handled correctly and that Vivox recovers gracefully when the interruption ends. This includes routing to the active audio device and setting up the audio configuration as described earlier in this section. SPAM is enabled by default. To disable SPAM, perform either of the following actions:
  • When you initialize the Vivox SDK, configure the 
    dynamic_voice_processing_switching
    parameter.
  • After the you initialize the Vivox SDK, call 
    vx_set_dynamic_voice_processing_switching_enabled()
    .