Eclipsa Audio on YouTube

YouTube streams immersive audio using IAMF, branded on the platform as Eclipsa Audio. Whether your mix actually reaches viewers as immersive comes down to one thing: what's inside the file you upload. This page walks through the one rule that matters, what YouTube preserves, and how to check that it worked.

Export from Orbit Pro 1.5.3 Beta

For IAMF export, we recommend Orbit Pro 1.5.3 Beta. It's the build we've verified end to end — export, upload, YouTube processing, and Eclipsa playback all confirmed working. If you're on an earlier build and an upload misbehaves, re-export from 1.5.3 Beta.

For YouTube, Upload IAMF Only

For a YouTube upload, send a single audio track — the IAMF stream

When you upload to YouTube, the file should carry one audio track: the IAMF stream. YouTube builds its own stereo and surround fallbacks from it.

YouTube needs a Base-profile export — not objects

Export Base profile with a Channel-based element, a Scene-based element, or both in a single Mix Presentation (the 7.1.4-plus-ambisonics file we tested is exactly this). YouTube does not currently accept Base-Enhanced exports that contain objects: an object-based upload won't receive an Eclipsa rendition, and the ffprobe check below can't read it either.

This is a YouTube (and FFmpeg command-line) limitation, not an IAMF one — object-based IAMF plays back fine in Orbit Lite, Orbit, Orbit Pro, and our upcoming Esfera platform. It's only YouTube that doesn't support it yet.

A stereo "compatibility" track is a reasonable thing to want in an export: it's what lets a file play for anyone, on any player, whether or not they support IAMF/Eclipsa. Keep it for QuickTime and for general distribution.

For YouTube, leave it out. YouTube builds its own stereo and surround renditions from your IAMF, so a second track is redundant — and today, if the file carries both, YouTube's ingest picks the stereo track and never builds an Eclipsa rendition at all.

In our testing, an MP4 carrying IAMF plus a stereo track was served as stereo to every viewer. The immersive mix sat unused inside the file, with nothing in Studio to explain why. The same session exported as IAMF-only was fully processed within hours and came back with a complete set of renditions, all derived from the immersive master:

• Eclipsa Audio — the IAMF itself, served to compatible devices
• Stereo — AAC and Opus, for everyone else
• 5.1 surround — Dolby Digital (AC-3) and Dolby Digital Plus (E-AC-3), so your mix reaches living-room systems that have never heard of IAMF

So there's no downside to leaving your own stereo out here: YouTube generates every fallback for you. The open format is the master, and the legacy renditions come from it. One upload, every listener.

This is a limitation of YouTube's ingest today, not a reason to drop stereo from your exports in general. Match the export to the destination — IAMF-only for YouTube, a stereo-carrying version for QuickTime and anywhere else, and keep both files if you need both. We'd expect YouTube's ingest to get better at reading the AAC and IAMF streams together over time; until it does, this is the split.

Check a file for IAMF in the terminal

Before you upload — or when a video came back stereo-only — you can confirm exactly what's inside a file with FFmpeg's ffprobe. Reading the IAMF structure needs FFmpeg 7.1 or newer.

ffprobe your-file.mp4

An Orbit Pro IAMF export shows the immersive audio as stream groups, and stamps the container with the iamf brand:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'your-file.mp4':
    major_brand     : iamf
    compatible_brands: iamfiso6mp41
  Stream group #0:0[0x1]: IAMF Audio Element:
  Stream group #0:1[0x2]: IAMF Audio Element:
  Stream group #0:2[0x3e8]: IAMF Mix Presentation:
      IAMF Audio Element #0:0[0x1]
      IAMF Audio Element #0:1[0x2]
  Stream #0:11[0x2](und): Video: h264 (High) ..., 1920x1080, 24 fps

The lines that matter:

• IAMF Audio Element and IAMF Mix Presentation stream groups — that's your immersive audio. (Two Audio Elements here: a channel-based 7.1.4 element and a scene-based ambisonics element, combined into one Mix Presentation.)
• major_brand : iamf — the container itself is an IAMF file.

Note there is no top-level Stream #0:N: Audio: line — only the video. In an IAMF-only file, all the audio lives inside the IAMF stream groups. That's exactly what you want before uploading to YouTube.

Spotting a stray stereo track

If the file also carries a plain audio track, ffprobe lists it as its own stream next to the IAMF groups — a line like:

Stream #0:12(und): Audio: aac (LC), 48000 Hz, stereo

That aac … stereo line is the "compatibility" track YouTube's ingest will use instead of your IAMF. Re-export IAMF-only — with no second audio track — and it's gone.

Two one-liners if you just want a yes/no:

# Is the container stamped as IAMF?  → prints "iamf"
ffprobe -v error -show_entries format_tags=major_brand -of default=nw=1:nk=1 your-file.mp4

# Show only the IAMF structures
ffprobe -hide_banner your-file.mp4 2>&1 | grep -i iamf

If ffprobe shows the IAMF stream groups and no stray stereo track, the file is ready to upload.

What Survives the Trip

A note on this method

Confirming what YouTube actually delivered — i.e. that your upload received an Eclipsa rendition — currently means pulling the processed file back down and inspecting it, and downloading from YouTube is technically against its Terms of Service. We take no responsibility for this method. We're sharing it because, given the current state of checking Eclipsa uploads, we believe this information is key to the format's success in these early stages. (Inspecting your own local export with ffprobe, above, is unaffected — that's just your own file.)

We pulled our uploads back down and inspected what YouTube actually delivers to Eclipsa-capable devices. The answer: your mix structure, intact. Both Audio Elements in our test — a 7.1.4 ChannelBased element and a first-order ambisonics SceneBased element — came back preserved, along with the Mix Presentation, its stereo and 7.1.4 layouts, and every annotation. YouTube re-packages the stream, but it doesn't flatten your work into a fixed bed.

How Long, and How to Check

Expect the standard renditions (stereo, then surround and Eclipsa) to appear over the first few hours after upload. Playback currently needs a 2025-or-later Samsung TV or soundbar, select LG 2025 models via firmware update, or any 2026 LG TV — desktop browsers are served stereo for now, even on Eclipsa-enabled videos.

You don't need a compatible TV to hear the immersive mix, though. Orbit Lite plays IAMF video back locally — for free — as do Orbit and Orbit Pro, so you can confirm your export sounds right before or after it goes up.

The silent diagnostic

And the diagnostic that would have saved us a day: if your video is still stereo-only after 24 hours, don't wait — check your file for a second audio track. That's the failure mode, and it's silent.

Try it yourself

Want to see the whole round-trip? These are the exact files from our testing — watch the result, re-upload the file, or rebuild it from the session:

• Watch the example on YouTube — our Orbit Pro export, live as Eclipsa Audio. On a compatible device (see above) you'll hear the immersive mix; a desktop browser is served stereo.
• Download the IAMF-only MP4 (~78 MB) — the exact file we uploaded. Put it on your own channel to confirm the workflow end to end.
• Download the Orbit session (~1.8 GB) — open it in Orbit Pro 1.5.3 Beta, export with the YouTube preset, and reproduce the whole thing from source.

When something goes wrong

If your upload comes back stereo-only, or processing stalls, see YouTube: video is stereo-only or stuck for the quick fixes.