by Florian Grond, PhD

In this blog entry, I will first give a brief overview of HOA, followed by an explanation of some relevant features of Dolby Atmos. Then, I will describe the general workflow connecting both approaches to create immersive audio experiences. I will conclude with some comments regarding the possibilities and limitations of some specific DAWs for the proposed workflow. 

Higher-order Ambisonics (HOA) plays a key role in all situations that require isotropic sound scenes, i.e. scenes that uniformly cover each direction. These scenes comprise VR, AR, XR, video games and generally speaking 360° audiovisual content, for instance when streaming over YouTube or Facebook. The key advantage of HOA is the ability to transform and conveniently manipulate the sound scene in a uniform and mathematically rigorous way. Ambisonics started in the 70ies through Michael Gerzon’s work with what today is referred to as first-order Ambisonics (FOA) [1]. Higher-order Ambisonics was developed in the 90ies by various researchers [2]; the spatial resolution and the sense of depth in the sound scene improved significantly. Without explaining Ambisonics in detail here I will cover some aspects that are relevant to the workflow; if you want to know more, I have compiled more about HOA below [3].       

The A- and the B-format
 
It is important to know that the raw output of an Ambisonics microphone array, the A-format, needs to be converted into what is known as the B-format before using it in an Ambisonics production workflow.  This is sometimes a bit of an obstacle for the novice. Unlike in a channel-based approach, the audio channels of the B-format are not associated in a direct way with spatial directions or positions, like the positions of speakers in the playback system, for instance. However, the more abstract representation of the sound scene in the B-format makes sound field operations like rotations fairly straightforward. 

​Although multichannel audio is at its base, the B-format is only an intermediary step and requires decoding before you can listen to a meaningful output. This decoding process can either yield speaker feeds ranging from classic stereo to multichannel surround sound setups for a conventional channel-based output, or it can result in a binaural experience over headphones. This is just one of the reasons why one would like to deliver immersive audio recorded through Ambisonics over playback solutions that support Dolby Atmos. For delivering a mobile and immersive listener experience with comparably small hardware requirements, the capabilities of headphones with integrated head-tracking are particularly attractive.

Ambisonic orders
 
For FOA recordings, the A- and the B-format have both 4 channels. The spatial resolution is limited, and sound sources usually appear as if they are all at the same remote distance. For full-sphere HOA solutions the A-format has typically more channels than the B-format. As an example, the ZYLIA ZM-1 has 19 channels as raw A-format output and 16 channels after converting it to 3rd order Ambisonics. It is important to remember these channel counts when planning your workflow with respect to the capacities of the DAW in question. 

Dolby Atmos is a surround sound technology developed by Dolby Laboratories. On the level of channel counts and positions, it expands on existing surround sound systems by adding height channels. While Dolby Atmos as a format is agnostic with respect to the speaker layout of the playback system, the inner workings are in part inspired by a channel-based approach. Dolby Atmos is not isotropic as Ambisonics is, however, it does aim in a similar way to envelop the listener from many directions, hence the desire to explore links with the immersive quality of HOA recordings.
 
In order to represent rich 360° audio content, Dolby Atmos can handle internally up to 128 channels of audio. The Audio Definition Model (ADM) ensures a proper representation of all the metadata related to these channels. Dolby Atmos files are distributed through the Broadcast Wave Format (BWF) [4]. From a mixing point of view, and also for combining it with Ambisonics, it is important to be aware of two main concepts in Dolby Atmos: beds and audio objects.  

Beds
 
You can think of beds in two ways:
 

1. Beds are a channel-based-inspired representation of audio content following surround sound speaker layouts plus additional up to 4 height channels.
2. In terms of audio content that you would send to beds, this can be for instance music that you mix for a specific surround setting. You can also think of it in general terms as soundscapes that provide a background or atmosphere for other audio elements. This background sound is spatially resolved. 

 
If you think for instance of a nature soundscape, this could be trees with rustling leaves and a creek with running water, all sound sources with more or less distinct positions. Take an urban soundscape as another example and think of traffic with various moving cars, these are sound sources that change their positions, but you would want to use the scene as is and not touch the sources individually in your mix. These are all examples of immersive audio content that you would send to beds. 

Audio objects
 
Dolby Atmos also allows for sounds to be interpreted as objects with positions in three dimensions. In a mix, these are objects that allow for control of their position in x, y, and z independently of the position of designated speaker channels. See below [5], for reading up more on beds and objects.

There are many ways how HOA sound material can be used in Dolby Atmos, involving both, beds and objects and the mixer is free to select or switch between those possibilities. For the scope of this article, let’s focus on mapping HOA to beds, in order to make a first step towards leveraging the immersive properties of Ambisonics with the end user format of Dolby Atmos. 

Mapping HOA to beds
 
While beds are channel-based in their conception, they may be rendered differently, depending on the speaker count and layout of your system. Think of beds as your main mix bus and let’s think of input for beds as surround configurations (2.0, 3.0, 5.0, 5.1, 7.0, 7.1, 7.0.2, or 7.1.2). In order to take advantage of the high resolution of 3rd order recordings made with the ZYLIA ZM-1, we will pick the 7.0.2 configuration with 7 horizontal and two elevated frontal speakers and we will decode the Ambisonic B-format to a virtual 7.0.2 speaker configuration. This results in a proper input for a Dolby Atmos bed.

The signal chain
 
Starting with a raw recording made with the ZYLIA ZM-1 we will then have the following signal chain:

STEP 1
Step one is the raw output of the microphone array, the A-format. For the ZYLIA ZM-1 this is an audio file with 19 channels. From a post-production and mixing perspective, all that matters here is where you placed your microphone with respect to the sound sources. If you want your work environment to include this step of the signal chain, the tracks of your DAW need to be able to accommodate 19 channels. But this is not absolutely necessary, you can start with step 2.

STEP 2
The 3rd order Ambisonic B-format contains 16 channels. For the conversion from step one to step two, you can use the Ambisonic Converter plugin from Zylia [6]. If your DAW cannot accommodate the necessary 19 channels for step one you can also convert offline with the ZYLIA Ambisonics Converter application, which also offers you batch conversion for multiple assets [7]. In many situations, it is advisable to start the signal chain with step 2, in order to save the CPU resources used by the A to B conversion for other effects. From a mixing perspective, operations that you apply here are mostly rotations, and global filtering, limiting or compression of the immersive sound scene that you want to send to Atmos beds. You will apply these operations based on how the immersive bed interacts with the objects that you may want to add to your scene later. There are various recognized free tools available to manipulate HOA B-format, for instance, the IEM [8] or SPARTA [9] plugin suites.

STEP 3
Then, The Ambisonic B-Format needs to be decoded to a virtual surround speaker configuration. For this conversion from the B-format, you can use various decoders that are again available from multiple plugin suites like IEM and SPARTA. ZYLIA Studio Pro [10] allows you to decode to a virtual surround layout directly from step one, the raw A-format recordings, which means that you can bypass step 2. For some background audio content, this maybe a perfectly suitable choice. Part of the roadmap for ZYLIA Studio Pro is to also offer A-format input, making it a versatile high-quality decoder. From a mixing perspective and depending on the content of your bed input, you may want to choose different virtual surround configurations to decode to. Some content might be good on a smaller, more frontal bed e.g. 3.1, and other content will need to be more enveloping. If your DAW has a channel count per track that is limited to surround sound setups, you will need to premix these beds as stems. 

STEP 4
​This bed then needs to be routed to Dolby Atmos. The details are beyond the scope of this article, and there are many excellent tutorials available that describe this process in detail. Here I want to mention that some DAWs have Dolby Atmos renderers built in, and you can study everything you practically need to know within these DAWs. With other DAWs, you will need to use the external Dolby Bridge [11]. This has a steeper learning curve to it but there are also many excellent tutorials out there that cover these topics [12]. There are also hardware solutions for Dolby Atmos renderings which interface with your speaker setup, but we will not cover them here. In Dolby Atmos, you will likely also integrate additional sources as objects, and you will control their 3D pan position with the Dolby Atmos Music Panner plug-in in your DAW. From a mixing perspective: the sonic interaction between the bed and the objects will probably make you revisit steps 2 and step 3 in order to rebalance, compress or limit your bed to optimise your mix.  

STEP 5
​You will need to monitor your mix to make sure that the end user experience is perfect. Only very few of us will have access to a Dolby Atmos studio for their work. For bedroom studio owners, you can listen to your mix always over headphones as a binaural rendering, on some recent OSX platforms over the inbuilt Atmos speakers, and with AirPods even over headphones with built-in headtracking. These solutions might be options depending on what you are producing for. Regarding this highly debated question, on whether you can mix and master over headphones, I found the following article very insightful [13], elaborating on all pros and cons and also pointing out that the overwhelming majority of end users will listen to music over headphones. With regards to an Ambisonic mix, using headphones means that the listener will be always in the sweet spot of the spatial reproduction.        

I will finish by discussing the steps of the signal chain on a couple of selected DAWs focusing on Ambisonics and beds only. In general, when planning your HOA to Dolby Atmos workflow, you need to understand how Dolby Atmos is supported in the DAW of your choice [14]. Either a Dolby Atmos renderer is integrated, or you need to get acquainted with the Dolby Bridge. On the side of HOA, you need to understand how many channels per track your DAW supports, and whether you can start working with the A-format, the B-format or premixed beds as stems.  

REAPER
Reaper is amongst the first choices when it comes to higher-order Ambisonics, due to its 64-channel count per track. Hence for the HOA aspect of the workflow sketched above, there are no limitations. However, you will need to familiarize yourself with the Dolby Bridge and the Dolby Atmos Music Panner plug-in.  

PRO TOOLS
In regular Pro Tools, you will also use the Dolby Atmos Music Panner plug-in and the Dolby Bridge. Since Pro Tools has a limitation of 16 channels per track, you will need to convert all your Ambisonic assets to B-format before you can start mixing. Upgrading to Pro Tools Studio or Flex [15] adds Dolby Atmos ADM BWF import/export, native immersive panning, I/O set-up integration with the Dolby Atmos Renderer, and a number of other Dolby Atmos workflow features as well as Ambisonics tracks.

LOGIC
In the most recent versions of Logic, Dolby Atmos is completely integrated, so no need to use the Dolby Bridge. For the monitoring of your mix, Logic will play nicely with all Atmos-ready features from Apple hardware. However, the channel count per track is limited to beds with 7.1.4. In theory, this means that you would have to premix all the beds as multichannel stems. While you can import ADM BWF files, as the Dolby Atmos project is ready for mixing, it is less obvious how to import a bed input as discussed above. In any case, once you have a premixed bed, the only modifications available to you in the mixing process are multi-mono plugins (e.g., filters), so you cannot rotate the Ambisonic sound field anymore at this point. To summarize for Logic, while Dolby Atmos is very well integrated, the HOA part of the signal chain is more difficult to realize.   

NUENDO
Nuendo also has Dolby Atmos integrated and it also features dedicated Ambisonic tracks up to 3rd order which can be decoded to surround tracks. This means you have a complete environment for the steps of the workflow described above. 

DAVINCI RESOLVE
While being mostly known as a video editing environment, DaVinci Resolve features a native Dolby Atmos renderer that can import and export master files. This allows for a self-contained Dolby Atmos workflow in Resolve without the need for the Dolby Atmos Production or Mastering Suite. DaVinci Resolve also has the Dolby Atmos renderer integrated and the tracks can host multichannel audio assets and effects. 

I hope this gives a general overview of how to connect HOA with Dolby Atmos. The proposed workflow is making use of beds in an orthodox way, but this is not the only way how HOA recordings can be mapped to Dolby Atmos. The 128 channels of Dolby Atmos including the object channels offer plenty of opportunities to explore.
 
If you like this article, then please let us know in the comments what we should describe in more detail in future articles?

[1] The publication by Michael Gerzon introducing FOA:

• M. Gerzon, "Periphony: With Height Sound Reproduction," J. Audio Eng. Soc., vol. 21, no. 1, pp. 2-10, (1973 February.)

[2] References for early works on HOA:

• J. Daniel, J. Rault, and J. Polack, "Ambisonics Encoding of Other Audio Formats for Multiple Listening Conditions," Paper 4795, (1998 September).
• R. Nicol, and M. Emerit, "3D-Sound Reproduction Over an Extensive Listening Area: A Hybrid Method Derived from Holophony and Ambisonic," Paper 16-039, (1999 March).
• An article by Jérôme Daniel about the HOA from the Ambisonics symposium 2009: LINK​

[3] A great source for HOA:     

• F. Zotter, M. Frank, "Ambisonics: A practical 3D audio theory for recording, studio production, sound reinforcement, and virtual reality", Springer Nature; 2019: LINK

[4] You can get access to Dolby’s Audio Definition model (ADM) specification here: LINK

• Here, you find more information about the broadcast Wave format BWF: LINK

[5] More information about the difference between beds and objects: LINK
[6] The Zylia Ambisonics Converter plugin: LINK
[7] The Zylia Ambisonics Converter: LINK
[8] The IEM plugin suite: LINK
[9] The SPARTA plugin suite: LINK
[10] Zylia Studio Pro plugin: LINK
[11] A video tutorial for using the Dolby Bridge with Pro Tools: LINK
[12] A video tutorial for using the Dolby Bridge with Reaper: LINK
[13] An blog post about the limits and possibilities of mixing Dolby Atmos via headphones by Edgar Rothermich: LINK
[14] Information about Dolby support for various DAWs: LINK
[15] Here you can compare Protools versions and their Dolby and HOA support: LINK

In July 2021, Jordan Rudess (Dream Theater) and his friends Steve Horelick and Jerry Marotta gathered at the Dreamland Recording Studios, NY, for a spectacular and singular concert event, spanning classical to impressionistic piano genres to progressive, experimental rock with spacious synth soundscapes. The team at Zylia captured the performance with multiple 360° cameras and 3rd order Ambisonics microphones, allowing the creation of a unique, immersive 3D journey.         
 
Zylia’s 3D Audio recording solution gives artists a unique opportunity to connect intimately with the audience. Thanks to the Oculus VR application, the viewer can experience each uniquely developed element of the performance at home as vividly as it would be by a live audience member. Using Oculus VR goggles and headphones, viewers have the opportunity to:

• watch the concert from several different perspectives each with a 360° view,   
• listen to the music in 360° spatial audio at every vantage point,
• tilt and turn their head and witness how 3D audio follows their movement perfectly
• hear the unique acoustics of the venue,
  
• feel the fantastic atmosphere of the event.

To create a multi-point 360° audio-video experience, we set up a recording spots on the stage amongst the musicians – each equipped with a ZYLIA ZM-1S and a 360° camera. This allows a listener to choose from which point they watch the concert and experience it in immersive 360°. With every move, the sound projected to the listener’s ears changes, corresponding to the position of their head. To combine 360° video with 360° audio, we used a video editor (Adobe Premiere), a Digital Audio Workstation supporting 19-channel tracks (Reaper) as well as Unity3D and Wwise engines.

Recording was done using ZYLIA 6DoF Recording Application. Qoocam 8K cameras were used for video recording.

A RAW signal from microphones was synchronized using ZYLIA 6DoF Recording Application and converted to 3rd order Ambisonics format. Output Ambisonics signals were mixed in DearVR software.

The 360° videos from the Qoocam 8K were stitched and converted to an equirectangular video format.

For the purpose of distributing the concert, a VR application was created in Unity3D and Wwise engines for Oculus Quest VR goggles.

Multi-point 360° audio and video – the outcome

The outcome of this project is an Oculus application with the concert “Jordan Rudess & Friends in 3D Audio” – an immersive, deep, and emotionally engaging music experience.

For this workflow you will require:

• MacOS system (with connection to Ethernet + WiFi)
• Insta360 One R camera,
• Insta360 mobile app installed on your smartphone
• ZM-1 microphone
• OBS (https://obsproject.com/)
• ZYLIA Streaming application (https://www.zylia.co/zylia-streaming-application-download.html)
• MacOS RTMP Local host application (https://github.com/sallar/mac-local-rtmp-server)
• Facebook profile

This project consists of 3 main parts:
A. Receiving a live 360° video from the Insta360 to OBS
B. Receiving Ambisonics audio from the ZM-1microphone to OBS.
C. Configuring Facebook for live stream of 360° video with Ambisonics audio

​A. Receiving a live 360° video from the Insta360 to OBS
1. Turn On the Insta360 camera and connect your computer Wi-Fi to the corresponding Insta360 Wi-Fi network.

2. Simultaneously, connect your computer to your local ethernet using an ethernet cable. On your network preferences you should be connected with Ethernet and Wi-Fi.
On step number 4 you will need the IP address for the Insta360 Wi-Fi referred on your network preferences.

3. On your MacOS, open the application Local RTMP server (https://github.com/sallar/mac-local-rtmp-server).
This simple application will be used to receive a live stream from the Insta360 camera. It also provides you the local host address for OBS.

5. Open OBS and setup your project:

• On the video resolution you require a 2:1 format such as 1280x640
• Also, select your audio to 4.0 to receive 1st order Ambisonics audio later.

6. To receive the video stream from the Insta360 to OBS:

• On the Sources, click the plus sign and add “Media Source”
• Disable “Local File”
• On the input add the same address as the Insta360 camera, you may also use:
  • rtmp://localhost/live/abc

After adding the source, you should be receiving a 360° video from the Insta360 into OBS.

B Receiving Ambisonics audio from the ZM-1microphone to OBS.

7. Connect your ZM-1 microphone to your computer.
Open ZYLIA Streaming application.

8. In OBS, add source select ZYLIA Streaming application.

You are now receiving 1st Order Ambisonics audio (4 channels) and a 360° video into OBS.

​C Setup Facebook for livestreaming

​On the Settings – Stream, enable “Broadcast this as a spherical video” and also “This broadcast has Audio 360 (ambix4)”.

10. In OBS press “Start Streaming”. You are now live!

Some of you, who came across the term ‘3D sound’, probably are wondering what it actually is?
Intuitively, we may understand it by analogy to 3D space, which as we know is made up of three dimensions: width, depth, and height. In real life, any position in space is characterized by these dimensions.
​
Now imagine, that you are outside, for example in a park, full of various sounds. You can hear children laughing on the playground behind you; a dog is barking on your left, a couple of people are talking while sitting on a bench in front of you – you can hear their voices more and more clearly when you move towards them. We may say that you are in the 3-dimensional sound space. When you move, the sound you hear changes as well, corresponding to the position of your ears (its intensity, direction, height and even timbre).

Reproducing this natural human way of hearing in the recording isn’t easy, however, we already have the technology which allows us to do it – it is binaural and Ambisonics sound.

​The most common type of recordings – which you hear while listening to the music on your computer or watching TV –is stereo. You may also come across mono recordings but these have been outdated with the introduction of stereo mixing. Stereo sound basically allows you only to hear if the sound comes from left or right which is the main advantage over the mono-type of audio.
​
Bellow, you may find some great recordings that will allow you to hear the difference between these different formats. We have also summarized their characteristics in the bullet points, to present the information most clearly.

by Pedro Firmino

In this adaptation, we will show you how to create a 360 video with 3rd Order Ambisonics audio using:

• MacOS
• ZYLIA ZM-1 microphone
• ZYLIA Ambisonics Converter plugin
• IEM Binaural Decoder
• Reaper
• Modifed version of Google Spatial Media Metadata injector created by professor Angelo Farina.

​

This tutorial consists in 2 parts:
A: Preparing the 360 content with 16 channels
B: Injecting metadata using Spatial Media Injector version, modified by Angelo Farina.

At the moment, only HOAST library ( https://hoast.iem.at/ ) is the only platform which allows online video playback of 3rd Order Ambisonics and therefore the content created from this tutorial is meant to be watched locally using VLC player.

For this tutorial, basic Python knowledge is advised.

For preparing a 360 video with 1st order Ambisonics, visit the link:
https://www.zylia.co/blog/how-to-prepare-a-360-video-with-spatial-audio

1. As usual, start by recording your 360 video with the ZYLIA ZM-1 microphone and remember to have the front of the ZM-1 aligned with the front of the 360 camera.

2. After recording, import the 360 video and the 19 Multichannel audio file into Reaper.
Syncronize the audio and video.

​3. On the ZM-1 audio track, insert ZYLIA Ambisonics Converter and select 3rd Order Ambisonics. This will decode your 19 multichannel track into 16 channels (3rd Order Ambisonics).

​4. On the Master track, click on the Route button, On the track channels, select 16. Now you are receiving the signal from the 16 channels from the audio track.

​5. Once the video is ready for exporting, click File – Render.

As for the settings:
Sample rate: 48000
Channels: 16 (click on the space and manually type 16)
Output format: Video (ffmpeg/libav encoder)
Size: 3840 x 1920 (or Get width/height/framerate from current video item
Format: QT/Mov/MP4
Video Codec: H.264
Audio Codec: 24 bit PCM

Render the video.

After having the 360 video with 16 channels, it is necessary to inject metadata for Spatial Audio.

In order to do this, Python is required. Python is preinstalled in macOS but
you can download Python 2.7 version here: https://www.python.org/download/releases/2.7/

Afterward, download Angelo Farina’s modified version of Spatial Media Metadata Injector, located at:
http://www.angelofarina.it/Ambix+HL.htm

​The next part:

1. With the downloaded file located in your Desktop, run macOS Terminal application.
2. Using “cd” command, go to folder where you have Spatial Media Injector (eg. “cd ~/Desktop/spatial-media-2/”)

3. Run Python script “sudo python setup.py install”. Type your password.

​After the build is complete, type command: “cd build/lib/spatialmedia”

6. Enter python gui.py and the application should run.

​With the Spatial Media Metadata Injector opened, simply open the created 360 video file, and check the boxes for the 360 format and spatial audio. Inject metadata and your video will be ready for playback using 3rd Order Ambisonics audio.

In this tutorial we describe the process of converting 360 video and 3rd order Ambisonics to 2D video with binaural audio with linked rotation parameters.
This allows us to prepare a standard 2D video while keeping the focus on the action from the video and audio perspective.
It also allows us to control the video and audio rotation in real time using a single controller.

Reaper DAW was used to create automated rotation of 360 audio and video.
Audio recorded with ZYLIA ZM-1 microphone array.

Below you will find our video and text tutorial which demonstrate the setup process.
Thank you Red Bull Media House for providing us with the Ambisonics audio and 360 video for this project.

Ambisonics audio and 360 video is Copyrighted by Red Bull Media House Chief Innovation Office and Projekt Spielberg, contact: cino (@) redbull.com
Created by Zylia Inc. / sp. z o.o. https://www.zylia.co

Requirements for this tutorial:

•  Video and audio recorded with 360 video camera and ZM-1 microphone
•  ZYLIA Ambisonics Converter plugin
•  IEM Binaural Decoder
•  Reaper

We will use Reaper as a DAW and video editor, as it supports video and multichannel audio from the ZM-1 microphone.

Before recording the 360 video with the ZM-1 microphone make sure to have the front of the camera pointing the same direction as the front of the ZM-1 (red dot on the equator represents the front of the ZM-1 microphone) , this is to prevent future problems and to know in which direction to rotate the audio and video.

​Step 1 - Add your 360 video to a Reaper session. 

The video file format may be .mov .mp4 .avi or other.
From our experience we recommend to work on a compressed version of the video and replace this media file later for rendering (step 14).

To open the Video window click on View – VIDEO  or press Control + Shift + V to show the video.

Step 2 - Add the multichannel track recorded with the ZM-1 and sync the Video with the ZM-1 Audio track.

Import the 19 channel file from your ZM-1 and sync it with the video file.

​Step 3 – Disable or lower the volume of the Audio track from the video file.

Since we will not use the audio from the video track, we require to remove or put the volume from the audio track at minimum value. 
To do so, right click on the Video track – Item properties – move the volume slider to the minimum.

​Step 4 – Merge video and audio on the same track.

Select both the video and audio track and right click – Take – implode items across tracks into takes
This will merge video and audio to the same track but as different takes.

​Step 5 – Show both takes.
​
To show both takes, click on Options – Show all takes in lanes (when room) or press Ctrl + L

Step 6 – Change the number of channels to 20.

Click on the Route button and change the number of track channels from 2 to 20, this is required to utilize the 19 multichannel of the ZM-1.

​Step 7 - Play both takes simultaneously.

If we press play right now, it will only play the selected take, therefore we need to be able to play both takes simultaneously, therefore:

Right click on the track – Item settings – Play all takes.

​On the preset selection, choose Equirectangular/spherical 360 panner, this will flatten your 360 video allowing you to control the camera parameters such as field of view, yaw, pitch and roll.

Step 9 – As FX, add ZYLIA Ambisonics Converter plugin and IEM binaural Converter.

 On the FX window add as well:

• ZYLIA Ambisonics Converter plugin and set it to 3rd Ambisonics Order. Make sure to set the microphone orientation how you recorded it in the first place.
• IEM Binaural Decoder. Here you can choose headphone equalization at your liking.

You should now have the binaural audio which you can test by changing the rotation and elevation parameters in ZYLIA Ambisonics Converter plugin.

​Step 10 – Link the rotation of both audio and video.

The next steps will be dedicated to linking the Rotation of the ZYLIA Ambisonics Converter and the YAW parameter from the Video Processor.

On the main track, click on the Track Envelopes/Automation button and enable the UI for the YAW (in Equirectangular/spherical 360 panner) and Rotation (in ZYLIA Ambisonics Converter plugin).

​Step 11 – Control Video yaw with the ZYLIA Ambisonics Converter plugin.

On the same window, on the YAW parameters click on Mod…  (Parameter Modulation/Link for YAW) and check the box Link from MIDI or FX parameter.
Select ZYLIA Ambisonics plugin: Rotation

Step 12 – Align the position of the audio and video using the Offset control.

On the Parameter Modulation window you are able to fine-tune the rotation of the audio with the video.
Here we changed the ZYLIA Ambisonics plugin Rotation Offset to -50 % to allow the front of the video match the front of the ZM-1 microphone.

Step 13 – Change the Envelope mode to Write.

To record the automation of this rotation effect, right-click on the Rotation parameter and select Envelope to make the envelope visible.

​After, on the Rotation Envelope Arm button (green button), right click and change the mode to write.

​By pressing play you will record the automation of video and audio rotation in real time.

Step 14 – Prepare for Rendering

After writing the automation, change the envelope to Read mode instead of Write mode.

​Disable the parameter modulation from the YAW control:
Right click on Yaw and uncheck “Link from MIDI or FX parameter”

​OPTIONAL: Replace your video file with the uncompressed version.

If you have been working with a compressed video file, this is the time to replace it with the original media file. To do this, right click on the video track and select item properties.

Scroll to the next page and click Choose new file.
Then select your original uncompressed video file.

​Step 15 – Render!

You should now have your project ready for Rendering.
Click on File – Render and set Channels to Stereo.
On the Output format choose your preferred Video format.
We exported our clip in .mov file with video codec H.264 and 24bit PCM for the Audio Codec.

by Eduardo Patricio

In general VR related workflows can be complex and everyone seems to be looking for standard solutions. Here, we will show you, step by step, how to prepare a 360 video with spatial audio in, possibly, the shortest way! 

Required gear:

• ZYLIA ZM-1 microphone array;
• A 360 camera (e.g. Insta 360 One X);
• A computer.

​After following steps A, B and C, you’ll have a video file with 1st order Ambisonics spatial audio that can be played on your computer with compatible video players (e.g. VLC) or uploaded to YouTube.

​Having said that, a small horizontal offset is not the end of the world 

With the gear in place, start recording both audio and video and clap in between the mic and the camera. The clap sound spike can be used to sync the footage later.

• Bring your files (the 19-channel audio from the ZM-1 and the video one from your camera) onto the DAW;
• Lower the video volume;
• Align the clap position;
• Trim the ends;
• Adjust the volume of the audio file;
• Add ZYLIA Ambisonics Converter Plugin to the audio track and adjust the settings;
• Change the master output to 4 channels;
• Render!

Here’s a video showing all the sub-steps in Reaper:

​Note
If you need to check how the recording sounds, add a binaural decoder plugin (e.g. IEM Binaural decoder) to the audio track, after ZYLIA Ambisonics Converter.
 

That’s it!
Now you can enjoy the spatial audio

• By playing it on your computer, using VLC player, for example (very few players will handle 360 video + Ambisonics correctly); or…
• By uploading it to YouTube. 

*Software tools used
​

Mounting:
https://www.amazon.com/Stage-MY550-Microphone-Extension-Attachment/dp/B0002ZO3LK/ref=sxbs_sxwds-stvp?keywords=microphone+clamp+arm&pd_rd_i=B0002ZO3LK&pd_rd_r=6860690f-2adc-4b00-a80e-de436939ed2b&pd_rd_w=GlE2J&pd_rd_wg=qrTTx&pf_rd_p=a6d018ad-f20b-46c9-8920-433972c7d9b7&pf_rd_r=GGS60M0DGQ5DQF44594V&qid=1575529629
 
https://www.amazon.com/Aluminum-Microphone-Swivel-Camera-Monitor/dp/B07Q2V6CBC/ref=sr_1_186?keywords=microphone+boom+clamp&qid=1575529342&sr=8-186

Amazon:
https://www.amazon.com/Neewer-Adjustable-Articulating-Mirrorless-Camcorders/dp/B07SV6NVDS/ref=sr_1_205?keywords=microphone+clamp+arm&qid=1575531393&sr=8-205
Allegro generic alternative for us to test: https://allegro.pl/oferta/ramie-przegubowe-11-magic-arm-do-kamery-8505530470
 

We are happy to announce the new release of ZYLIA Ambisonics Converter plugin v1.4.0. 

​What would happen if on a rainy and cloudy day, during a walk along a forest path, you could move into a completely different place thousands of kilometers away from you? Putting the goggles on would get you into a virtual reality world, you would find yourself on a sunny island in the Pacific Ocean, you would be on the beach, admiring the scenery and walking among the palm trees listening to the sound of waves and colorful parrots screeching over your head.
​
It sounds unrealistic, but such goals are determined by the latest trends in the development of Augmented / Virtual Reality technology (AR / VR). Technology and content for full VR or 6DoF (6 Degrees-of-Freedom) rendered in real time will give the user the opportunity to interact and navigate through virtual worlds. To experience the feeling of "full immersion" in the virtual world, realistic sound must also follow a high-level image. Therefore, only each individual sound source present in virtual audio landscape provided to the user as a single object signal can reliably reflect both the environment and the way the user interacts with it.

There are many possibilities of using a 6DoF VR technology. You can imagine exploring a movie plan in your own pace. You could stroll between the actors, look at the action from different sides, listen to any conversations and paying attention to what is interesting only for you. Such technology would provide really unique experiences.

​A wide spectrum of virtual reality applications drives the development of technology in the audio-visual industry. Until now, image-related technologies have been developing much faster, leaving the sound far behind. We have made the first attempts to show that 6DoF for sound is also achievable.

​It's extremely challenging to record high-quality sound from many sources present in the sound scene at the same time. We managed to do this using nine ZYLIA ZM-1 multi-track microphone arrays evenly spaced in the room.

In our experiment the sound field was captured using two different spatial arrangements of ZYLIA ZM-1 microphones placed within and around the recorded sound scenes. In the first arrangement, nine ZYLIA ZM-1 microphones were placed on a rectangular grid. Second configuration consisted of seven microphones placed on a grid composed of equilateral triangles.

​Microphone signals were captured using a personal computer running GNU/Linux operating system. Signals originating from individual ZM-1 arrays were recorded with the specially designed software. 

​We recorded a few takes of musical performance with instruments such as an Irish bouzouki (stringed instrument similar to the mandolin), a tabla (Indian drums), acoustic guitars and a cajon.

To present interesting possibilities of using audio recorded with multiple microphone arrays we have created a Unity project with 7 Ambisonics sources. In this simulated environment, you will find three sound sources (our musicians) represented by bonfires among whom you can move around. Experiencing fluent immersive audio becomes so natural that you can actually feel being inside of this scene.

​During exploration experiments, MPEG Standardization Committee has realized that there is a lack of test material for audio and video experiments into MPEG-I Immersive Video. Our recordings have been accepted as a reference material in MPEG Standardization Committee. Each of the experts involved in standardization works on MPEG-I can now use the Zylia recordings to develop and test audio technologies for VR/AR applications.