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Audio Is it possible to record spatial audio for 360 video in Unity?

Discussion in 'Audio & Video' started by Robinvanlierop, Jun 16, 2017.

  1. Robinvanlierop

    Robinvanlierop

    Joined:
    Oct 17, 2016
    Posts:
    1
    I use a plugin called Helios3D for Unity to record 360 footage in my real-time Unity environment. My intention is to upload the result to Youtube.

    The plugin supports audio recording but only regular audio, not specifically spatial audio.

    I contacted the developer of the plugin to ask if spatial audio recording was possible but he said that Unity simply did not support it, but he didn't go into further details.

    I was wondering if there exists a way to record the audio in the specific format that Youtube spatial audio requires? Or if anyone had ever attempted to make a script that does this sort of thing?

    • Content you upload should follow YouTube specifications, including the use of:
      • First Order Ambisonic (FOA) audio channel layouts
      • ACN channel ordering
      • SN3D normalization
      • FOA components W, Y, Z, X should have channel map indexes 0, 1, 2, 3, respectively. The channel_map sequence should be specified as 0, 1, 2, 3.
      • Use the metadata tool to insert Spatial Audio metadata. If your post-production tools already mark metadata per the YouTube spec, you don't need to use the metadata tool.
    • MP4 files require AAC encoding with 4.0 layout
    • MOV files require either AAC encoding with 4.0 layout or PCM encoding with 4.0 or unspecified layout
    • AAC sample rates and bitrates should use YouTube encoding recommendations. AAC sample rates should be 96 khz or 48 khz and bitrates should be 512 kbps. For best quality, we recommend that you use an uncompressed PCM audio format.
    • Only one audio track is supported. Multiple audio tracks, such as tracks with spatial and stereo/mono in the same file, are not supported.

    Cheers
     
  2. DanielRothmann

    DanielRothmann

    Joined:
    Feb 4, 2016
    Posts:
    10
    I'm afraid it would be quite difficult to set up. Ambisonic recordings rely on some clever phase inversion tricks dependent on unidirectional microphone capsules - As far as I know, AudioListeners in Unity act more like a simple omnidirectional capsule.

    If you find a way to record multiple AudioListeners, you could try to set them up in a quad configuration around the camera and transcode the quad (four channels) recording to B-Format:
    http://www.ambisonic.net/quaduhj.html