YouTube Ambisonics: the Spatial Audio Experience for VR Video

Ambisonics is a cutting-edge audio technology that provides a full-sphere surround sound experience, capturing sound from all directions and enhancing the immersion of VR and 360° videos.

Well, cutting-edge depends a bit on how you define it. To be honest, Ambisonics is quite an old format but has been implemented into YouTube in 2016.

Users may need to sign in to access certain Ambisonic channel content and videos or to discuss data access and unblocking issues with YouTube support.

YouTube’s added support for Ambisonics allows creators to offer a richer, more engaging audio experience combined with VR Videos, or 360 Videos added.

Update 2024

Supported Hardware and Platforms:

Spatial audio on YouTube only works on non-Apple hardware and is limited to the following platforms:

Android app for smartphones and Quest

Chromium-based browsers on Windows PCs (Edge, Chrome)

Reduced Audio Support

YouTube has discontinued support for 4+2 channel spatial audio with Ambix 1st Order plus two additional headlocked channels. Now, it only supports plain Ambix with four channels.

Video Quality

Even if you upload a video in 5.7k or 8k resolution, YouTube will downgrade it to 4k. This not only impacts the visual quality but can also diminish the immersive experience for your audience.

Additional Issues

On iPhone, spatial audio has been broken for a while, and Safari has never supported it. Uploading a 360 video with spatial audio to YouTube today, I noticed that almost everything seems broken. Most of my older videos don’t track audio anymore on Firefox and Google Chrome (on Mac M1), and 8K resolutions from a few years ago have vanished. It feels like YouTube is frequently changing things under the hood, often breaking features in the process.

Conclusion: Consider Alternative Platforms

Write a support ticket. When several people show a sign of inconvenience changes are the application gets fixed.

What is Ambisonics?

Ambisonics records audio using multiple microphones to capture sound from all directions, then encodes it into a format that can be manipulated to create a 3D audio environment. This is particularly beneficial for VR applications, where an immersive audio experience enhances the application and overall impact. Learn more about Ambisonics.

Benefits of Ambisonics on YouTube

Enhanced Viewer Experience: Ambisonic audio offers a more immersive and engaging audio experience, especially for viewers using headphones or VR headsets.

Versatility Across Devices: Ambisonic audio can be experienced on various devices, including smartphones, VR headsets, and home theater systems, making it accessible to a wide audience.

Application in Different Content Types: While audio is particularly impactful for VR and 360° videos, Ambisonic audio also enhances the experience of traditional video content by providing a more enveloping sound experience.

Technical Requirements and Tips

Find the specs for your vr video here.

File Format: Ensure your audio is encoded in a format supported by YouTube, such as PCM in a MOV container.

Channels: Use the correct channel order (W, X, Y, Z) for First Order Ambisonics.

Metadata: Properly tag your video with the necessary metadata to signal YouTube’s player to decode the Ambisonic audio.

How to Use Ambisonics on YouTube

Create Ambisonic Audio: Record or produce audio using Ambisonic techniques, typically with a special microphone array. Learn 360 sound production.

Encode the Audio: Encode the audio into a compatible Ambisonic format. YouTube supports First Order Ambisonics (FOA), which uses four channels (W, X, Y, Z).

Integrate with Video: Combine your Ambisonic audio with your 360° or VR video, ensuring synchronization for spatial accuracy.

Upload to YouTube: Upload your video with the appropriate metadata to inform YouTube that it contains Ambisonic audio.

Minimum Requirements for Spatial Audio on YouTube

Metadata: Ensure your file includes the necessary metadata. Use YouTube’s metadata tool or compatible post-production tools.

Single Audio Track: Only one audio track is supported. Multiple tracks in the same file are not supported.

Ambisonics Format: Use Ambisonics (AmbiX) format with ACN channel ordering and SN3D normalization.

Supported First Order Ambisonics (FOA) Formats:

4-Channel Audio Track (W, Y, Z, X): Sample rate: 48 kHz

PCM encoded in MOV container

AAC encoded in MP4/MOV container: Min. bitrate: 256 kbps

OPUS encoded in MP4 container: Channel mapping family: 2, Min. bitrate: 512 kbps

Supported FOA with Head-Locked Stereo:

6-Channel Audio Track (W, Y, Z, X, L, R): Sample rate: 48 kHz

PCM encoded in MOV container

OPUS encoded in MP4 container: Min. bitrate: 768 kbps, Channel mapping family: 2

Learning and Implementing Ambisonics

For those new to Ambisonics, numerous resources, videos and tutorials are available online. Learning how to capture, encode, and integrate Ambisonic audio can be a valuable skill for content creators looking to learn how to push the boundaries of their audio-visual projects.

YouTube and Head-Locked Audio Implementation

YouTube took a considerable amount of time to implement head-locked audio, a feature that ensures sound remains fixed relative to the user’s head movements. This delay meant that users could not fully experience the immersive spatial audio potential of VR and 360° videos on the platform.

However, with the introduction of head-locked stereo audio, YouTube has enhanced the spatial audio experience, providing a more realistic and stable head and sound environment for viewers.

Facebook’s Advanced Ambisonics

Unlike YouTube, which supports First Order Ambisonics (FOA), Facebook employs a more advanced hybrid Higher Order Ambisonics (HOA) format known as TBE (Three-Dimensional Binaural Audio).

This format allows for a more detailed and immersive sound field experience with optional head-locked audio. The use of TBE on Facebook enables creators to deliver a richer and more versatile spatial head and audio experience, accommodating dynamic head movements while maintaining audio accuracy.

Spatial Audio Workstation used to be the go-to tool after TBE was acquired by Oculus (Meta) and even standard in ProTools for a while.

Device Support for YouTube Spatial Audio

YouTube’s spatial audio was initially well-supported across Android and iPhone devices, providing a seamless experience for mobile users. However, support on Mac devices has declined, leading to inconsistencies in the availability of spatial audio features.

Efforts are being made to update the application and improve compatibility across all platforms, ensuring that users on Macs can once again enjoy the full benefits of YouTube’s spatial audio capabilities. Keeping software and applications updated is crucial for maintaining an optimal spatial audio experience across all devices.

I try to keep track of the development in this 360 video file player overview file.

Conclusion

YouTube’s support for Ambisonics represents a significant step forward in providing richer, more immersive audio experiences. By understanding and utilizing this technology, content creators can elevate their videos, offering viewers an unparalleled sense of presence and realism.

Whether for VR, 360° videos, or traditional content, Ambisonics opens up new possibilities for engaging and immersive audio-visual storytelling.