Error Code:
AudioClippingInspector-AudioClippingDetected
Error Message:
Example: Audio clipping has been detected in channel 7 (Rt).
Example: Severe compression has been detected in channel 6 (Lt).
Definition:
AudioClippingInspector-AudioClippingDetected will trigger when the over-modulation is objectively clipping and expected to sound noticeably distorted, which negatively impacts the viewing experience. The error message will specify the audio channel where audio clipping was detected.
Audio tracks are analyzed on initial inspection to detect if audio clipping (i.e. over-modulation) has occurred. There are five ways audio clipping is detected and a threshold for each of the five methods reflects an empirical determination of "audibility" of that clipping artifact. If any of the following five criteria are met, the Audio Clipping Inspector will report the issue:
| Criteria | Threshold |
|---|---|
| At least one segment of audio clipping (sequential equal valued samples) at the maximum allowed signal level | -0.45dBFs |
| Many segments of audio clipping (sequential equal valued samples) at the asset's greatest volume | 10 unique segments |
| Too many audio samples at full scale (1.0 or -1.0) | 0.01% of total samples |
| Audio samples at a significantly higher volume than the asset's typical volume level | loudest samples > 1dB over remaining samples |
| Significantly more samples at the asset's greatest volume compared to incrementally quieter audio samples | 25% more samples at loudest level |
Solution:
Review the file which you have delivered to Backlot and check the audio on the channel where audio clipping was detected for over-modulation.
If over-modulation is found on the delivered file, check your source. If your source does not exhibit this error, it is possible that over-modulation was introduced at some point in your workflow. Return to the point in your workflow where you are able to verify audio is not over-modulated and commence re-processing from that point.
If the issue exists on your source, then seek an alternate master, or alternate audio stems which you can use to replace the affected audio. If you are unable to provide a better audio source please contact your Netflix representative via Backlot.
If you have reviewed the audio and cannot hear any issues, please contact your Netflix representative via Backlot.