feat: spatial audio stream & video player

[lorux0]

What does this PR change?

Fixes #6132

Protocol: decentraland/protocol#322
SDK: decentraland/js-sdk-toolchain#1243

Implements the possibility to set the audio as 3d on PBAudioStream and PBVideoPlayer.

IMPORTANT: There are limitations on the current AV Pro integration. Many formats and codecs are not supported and will not find the audio channel. It fallbacks to System Direct bypassing any unity configuration, meaning the AudioSource. According to documentation and some investigation, although needs confirmation:

Test Instructions

Run this scene: spatial-stream.zip
You will see a plane that outputs an audio as m4a. If you run to the cube, at the back, there is an audio stream going on. Both should be affected by spatial audio. You will hear it louder when you are close, but the more away you are, the volume will be lower. Additionally you can interact with the cube to change the spatial distance.

Quality Checklist

• Changes have been tested locally
• Documentation has been updated (if required)
• Performance impact has been considered
• For SDK features: Test scene is included

Code Review Reference

Please review our Code Review Standards before submitting.

[github-actions]

Windows and Mac build successful in Unity Cloud! You can find a link to the downloadable artifact below.

Name	Link
Commit	5c7e9a2
Logs	https://github.com/decentraland/unity-explorer/actions/runs/19706925443
Download Windows	https://github.com/decentraland/unity-explorer/suites/50841573591/artifacts/4688263355
Download Windows S3	https://explorer-artifacts.decentraland.org/@dcl/unity-explorer/branch/feat/stream-spatial-audio/pr-16151-5c7e9a2/Decentraland_windows64.zip
Download Mac	https://github.com/decentraland/unity-explorer/suites/50841573591/artifacts/4688333516
Download Mac S3	https://explorer-artifacts.decentraland.org/@dcl/unity-explorer/branch/feat/stream-spatial-audio/pr-16151-5c7e9a2/Decentraland_macos.zip
Built on	2025-11-26T16:17:35Z

[NickKhalow]

Nice work! Please address the comments

[davidejensen]

Very nice! Approved with 2 small questions and a very tiny suggestion that could also be easily ignored

[Ludmilafantaniella]

Approved ✔️

Tested on Windows and Mac following the instructions provided in the PR running the spatial-stream scene.

✅ What I verified

• Spatial audio works on both PBAudioStream and PBVideoPlayer.
• Volume increases when approaching the audio source and decreases with distance as expected.
• Interaction with the cube to change distance settings works correctly.
• Regression check: global audio continues to behave as before when spatial audio is disabled.

🎧 Notes on the camera/audio-listener behavior

I documented in the thread that the audio listener being tied to the camera (Unity default) can create UX issues in some situations (e.g., avatar facing a screen but the camera positioned behind them → lower volume even though the user is “watching” the source).
After further testing, first-person view works correctly, and the current behavior is consistent with Unity’s spatial audio system.

Given the constraints and the plan to assess UX once this is used in real scenarios, I’m fine with moving forward.

6162-evi.mp4

cameraPos.mp4

✅Regressions performed:

• ✔️ Backpack and wearables in world
• ✔️ Emotes with sfx in world
• ✔️ Teleport with map/coordinates/Jump In
  • MF25
  • Casa Roustan
  • FashionWeek scene
• ✔️ Settings

comments resolved