APT: advanced techniques
This section describes various advanced procedures that can be used to effect better alignment between Guide and Dub, or to meet challenges that arise in processing using APT.
There may also be times when the processing creates audible artefacts, either in a small or large part of the signal. These artefacts may arise for a number of known signal-related reasons, which are generally understandable and fixable.
Examples of challenges include:
- Localized differences between the Guide and Dub signals as in:
- Vocal "creaks" (where the pitch drops briefly an octave lower or is unmeasurable)
- Phrase or word startup differences (onsets)
- Differences in phrase beginnings or endings being breathy
- Breaths taken between words differently in the two signals
- A word, words or other sound appears in one signal but is absent from the other (this is quite common in dialog replacement with noises occurring in the Guide track)
- Discontinuous signals: Having short sections of a Dub with silence between each short section and trying to align this discontinuous signal to a continuous Guide (or vice versa)
- Extra silence at start of signal file: Setting an APT input to start in possibly long stretches of digital silence before the signal starts can sometimes cause a problem
- Tight cuts at signal starts: Not giving an APT Dub input enough "non-signal" to allow it to be moved, if required.
- Different or extreme signal pitch ranges
- Legato music lines where energy alone is an insufficient cue for alignment to be done effectively.
Most of these situations are quickly solvable using the automatic tools in Revoice Pro, and are discussed in this section or in the Warp section.
If the automatic tools don't solve the problem you may need to manually edit an attribute of the Output Track, or vary them over time using time-varying automation.
Topics in this section:
Gaps of silence in audio waveforms
Aligning signals that have limited dynamic range
Related topics: