Audio Corruption Occurs on MacOS ProTools

[BrandenAvalonCx]

Description

When using ProTools on MacOs, after opening the Export UI or performing an Export, audio becomes corrupted during DAW playback. Audio sounds "slow", as though it is being played back at the wrong sample rate. Audio played by the IAMF Validation player continues to play normally, only the DAW audio playback is affected.

The issue is caused by a conflict between the Pro Tools DAW and the IAMF Validation player trying to both use the same physical device. The issue can be mitigated by moving one or the other to a different physical device, or enabling audio aggregation in Pro Tools. See below for instructions on how to resolve the issue.

To Reproduce

• Create a new Pro Tools project on MacOs
• Add Audio Element and Renderer plugins as normal
• Export the Audio to an IAMF file
• Load the IAMF file into the IAMF validation player and play the file back
• Close the Renderer UI window and attempt to playback audio on the DAW

Temporary Resolution

This issue may be permanently resolved by changing the playback engine if possible:

• In Pro Tools, open the Playback Engine settings: Options --> Playback Engine
• Change the Playback Engine to Pro Tools Aggregate IO

Alternatively, this issue may be resolved by adding an additional physical playback device if it is a higher priority than the device Pro Tools is currently configured to use. For example:

• Configure Pro Tools to use the MacOs speakers in the Playback Engine and I/O settings
• Close Pro Tools
• Plugin in headphones, or another physical playback device, to the MacBook. Ensure this new device is the default playback device for the MacBook.
• Re-open ProTools
  This works by separating the DAW and validation player onto two separate physical playback devices, and setting ProTools to use the non-default playback device. The default device will be selected by the validation player.

Alternatively, using a different physical playback device for all audio may sometimes resolve the issue. For example:

• Configure Pro Tools to use the MacOs speakers in the Playback Engine
• Plugin headphones, or another physical playback device, to the MacBook
• Configure ProTools to play audio on the headphones using the I/O settings (Setup --> I/O... --> Output)
• Configure the mix bus to output to the headphone I/O
• Close and Re-Open ProTools

Finally, you can temporarily resolve the issue by avoiding loading audio into the validation player:

• Move or delete any previously exported IAMF files to prevent them from being automatically loaded into the validation player
• Restart ProTools
• After export and validation, move or delete exported IAMF files to prevent them from being automatically loaded into the validation player.

[BrandenAvalonCx]

Added a permanent resolution and more information to the issue description