In addition to real-time Loudness Measurement, the Dolby Atmos Renderer provides an offline loudness analysis function for open Dolby Atmos master files.
This can be used to verify that loudness target specifications have been met, and for generating summary reports and/or detailed logs that can be delivered along with master files.
The loudness analysis can be performed on the entire file, or on a user-specified range within the master. This ensures that loudness analysis does not include pre- or post-roll, which may affect the overall loudness reading.
Running Loudness Analysis
To perform offline Loudness Analysis on an open master file:
- Choose Window> Analyze Loudness, or press Command+L (Mac) or Ctrl+L (Windows). The Loudness analysis dialog box will display.
- (Optional) In the Optional Settings section, set the time range for the file:
- Click (enable) the Set manually radio button.
- In the In field, type in the timecode value where the Loudness Analysis should start.
- In the Out field, type in the timecode value where the Loudness Analysis should end.
- Click Analyze Loudness.
- A progress bar will display during the Loudness Analysis operation. The duration of the analysis depends on the duration of the content and the CPU specification.
On completion, the dialog will display the analysis results in five fields:
- Integrated – LKFS
- Integrated (dialogue) – LKFS
- Speech percentage – %
- Range – LU
- True peak – dBTP
These measurements are available for both Dolby Atmos (based on a 5.1 Re-render with the soft-clip encoding limiter applied) or Stereo/Binaural (based on the headphone render mode selected in Preferences or Settings).
Both selections have the option to export a loudness report:
- Export Dolby Atmos loudness report
- Export stereo or binaural loudness report
In the drop-down menu for each, the user can choose to export a Timeline or Summary report:
- Timeline Report – This is a .csv file which includes all five fields measured once per second. The Timeline Report is useful for analysis to determine where events that exceed loudness targets occur in a mix.
- Summary Report – This is a .txt file that includes the same information as presented in the UI. The Summary Report can be delivered along with master files as proof of compliance with specified Loudness Targets.