Interview with Hideo Irimajiri, Executive Creator, WOWOW

Hideo Irimajiri, Executive Creator, WOWOW

Could you please introduce yourself?

I joined MAINICHI BROADCASTING SYSTEM, INC. after completing my master’s degree at Kyushu Institute of Design in 1981. My work has always been in audio technology related fields at MAINICHI BROADCASTING SYSTEM, INC.

In 2018, I moved to WOWOW and have been working on 3D audio related projects since. WOWOW was established in 1991 as a pay-per-view satellite broadcasting station.

When and where did you hear about AURO for the first time?

The first time that I heard the AURO-3D sound was in 2018, at a private showing by D&M.

Last year, we could hear a live streaming concert in high quality immersive sound with HD picture over IP. This was a world premiere which turned out very well. Were you satisfied with the result?

I had high hopes for AURO-3D because they offer high sound quality that is very close to Lossless Coding, while other companies only offer 3D audio solutions using Lossy Codecs.

I had been unsatisfied so far with the sound quality of other commercial 3D audio technology providers, but when I first heard AURO-3D in 2018, I was really amazed because of its clarity of sound. Since then, I have been conducting many more experiments with AURO-3D.

I succeeded to perform an in-house experiment using AURO-Codec in combination with MEPG-4ALS to deliver 3D audio streams and receive it with a VLC player. In October of last year, I conducted a public distribution experiment to see how the public would evaluate the 3D audio result. As you have been able to witness yourself this streaming event at the Galaxy Studios in Belgium, the result is absolutely positive.

Please introduce your next project (POC) using AURO-3D.

In last year’s open experiment with AURO-3D, the feeling of being enveloped by the sound and the naturalness of the sound were very highly valued by the audience.

As some people reported that the VLC player was difficult to set up and indicated they could not even listen to the 3D audio, we decided to develop a player that is more user friendly and which we completed in September this year.  From December onwards, we will conduct an open distribution experiment with 3D audio using this new player with AURO-3D. This time, I would like to verify how 3D audio would be valued as a new service, so more than just a pure technical evaluation.

Is it difficult to work with AURO-3D format?

As a producer and engineer, I find AURO-3D very easy to use, because it is compatible with conventional PCM. For example, it is very convenient being able to listen to the result right away without having to decode it. With other 3D audio Codecs, you have to go through encoding and decoding to hear the sound, which is really a hassle.

Because AURO-3D is still compatible with PCM, it is convenient to use the same facilities that have been used in the past. The content can be stored on the server in exactly the same way as conventional PCM 5.1ch content, so no need for changing the system when adding 3D content.

How do you think about the future of immersive audio?

My prime concern is how to increase the number of people able to create 3D audio content. If we can increase the number of people who can produce 3D audio, more 3D content will become available.  I believe that increasing the number of high-quality 3D audio productions is a must to popularise 3D audio. As the first hearing of 3D audio has similar impact on the listener experience as when mono became stereo, I am convinced that 3D audio will become equally popular while more and more 3D audio becomes available.

Why AURO-3D?

One great advantage of AURO-3D is that it supports high-resolution audio at 96kHz sample rate. No matter how good the 3D audio content is, if the sound quality is not good, consumers will think the content is not good. By using AURO-3D, we can obtain both high sound quality and best-in-class immersive 3D audio.

With AURO-3D, the sound can be mixed and monitored in uncompressed audio quality (PCM) without having to go through the Codec process. Afterwards, the mixed 3D audio can be processed with AURO-Codec followed by a final QC of the end product, exactly as we used to do.

With other companies’ systems, we can’t monitor the sound of the 3D audio while listening through the decoder as it will sound at consumers’ playback.  It first needs to be authored before having a master to check the audio quality at playback. So, listening to the mixed 3D audio with PCM signals is not possible, so it is not easy to verify if the sound quality has changed by the encoding and rendering itself.

During production, we regularly need to listen and verify the 3D audio how it will sound when delivered, and in case any problem occurs, we adjust the mix. This kind of straight forward production flow makes it very easy to make content in AURO-3D.