The Atmos audio is an audio file wrapped as a BWAV ADM file or an IAB MXF essence that encapsulates up to 128 channels. Atmos QC is performed in a minimum 7.1.4 speaker setup against the IMF proxy or MXF Video Essence.
Atmos is an important creative tool is because it allows the creatives more of an audible playing field. With its dynamic, immersive experience, the filmmaker is allotted more control over the soundscape and the impact it can have for the viewer in an emotional way.
Our expectation, unless otherwise specified, is a full linear review of source deliverable Atmos mix in a unity environment with a theatrical or home entertainment Atmos setup.
- Must be reviewed in an at minimum 7.1.4 speaker array.
- Atmos files do not need to adhere to the Netflix True Peak measurement spec.
- Limiting for mixes will be done on the consumer decode side.
- Please continue to measure True Peak and mark as an FYI only within any QC report.
- Atmos should still adhere to the Netflix LKFS measurement spec and should be noted as an issue if it does not.
- For native Atmos mixes, the 5.1 and 2.0 re-renders must conform to Netflix loudness and True Peak specification
- All Atmos should be conformed to the final IMF
- Atmos should be derived from the original language Printmaster Mix. It should be a full mix and also contain all object based information.
- In some cases, it may actually be the source for the 5.1 and 2.0 mixes.
- Atmos should include ALL elements included in the original session:
- All dialogue in the original language of the production
- All music, production sound, sound effects and foley
- Any treatments applied to the PM mix
- Correct placement of individual objects in relation to the on screen action
“Location” for Atmos Audio issues
The “location” of an issue within an audio asset should include the mix being analyzed and the Track/Channel name or number. Examples include, but not limited to:
- Right Top Overhead
- Object in Left Rear Surround
- 3,7,8, etc.
Measuring LKFS and True Peak
- Atmos files must adhere to Netflix LKFS measurement spec.
- Atmos does not need to adhere to the Netflix True Peak measurement spec. This should still be included as an FYI.
- Measure the default 5.1 Re-Render via Dolby Media Meter, Nugen LM Correct or Baton Auto QC.
The goal of Netflix’s Source-level Atmos QC is to ensure that all technical specifications are met, including but not limited to:
- volume levels
- audio defects
- missing elements