AudioSyncR

AudioSyncR (ASR) is a tool that enables the syncing of events based on the waveform of its audio streams.  Syncing is performed by first rendering a mono wave file for each selected audio event as well as the reference audio track.  The rendered wave files are then analyzed to find the position (sync point) in which the waveform of the event audio best matches the waveform of the reference audio.  Syncing based on the timestamps of the events files and reference file is also supported.

Quick Start Guide

1. Select events to be synced.  Note that either the video or audio portion of an event or both may be selected.
2. Launch AudioSyncR
3. Select the Reference Audio Track, e.g. the track containing audio from an external audio recorder.
4. Select type of sync--audio selected events or loop region for selected tracks
5. Select the default "Auto" option in Waveform Sync Processing Options.
6. Choose options to be performed after syncing
7. Choose location for temp folder
8. Click the "Start" button to begin syncing.

1. What to Sync

a. Select Reference Audio Track. From a list of all audio tracks, the user must select a reference track. 

b. Selected audio events .  If ticked, selected events will be synced.

c. Loop region for selected tracks .  If ticked, the loop region will be used for syncing selected tracks.

d. Audio Events to Sync.  If Selected audio events is chosen, the user must first select the events to be synced with the reference track before launching the script.  For an individual event, the user can select either the video or audio stream or both.  Once selected and the script launches only the selected audio events will be shown.  For each selected event, the following information is presented: track index (as shown), event index (zero-based), event start time, and active take name.

e. Tracks to Sync .  If Loop region for selected tracks is selected, the user can select the tracks to be synced.  Instead of events, all audio tracks will be shown.

f.   Resets all selections.

g.   Zoom to project.  If clicked, the timeline will be zoomed out to display the entire project.

h.   Zooms in to the selected event.

i.   Moves to the next selected event.

j.   Moves to the previous selected event.

k.   Removes the selected event from the list of events to be synced.

2. Date/Time Stamp Sync Processing Options .  If the positions of selected events relative to the reference audio track are unknown, it may be helpful to first perform a sync based on the Date and Time of encoding which is embedded in most media files.  If such metadata is not available, the files “Date Modified” will be used.  For example, suppose that I have 4 to 5 minutes of GoPro video files that I wish to sync against a 3 hr audio file recorded on a Zoom.  Without pre-syncing using the files encoding date time, the processing time could become very lengthy.

a. Pre-sync with file Date Time Stamp .  If ticked, events will first be synced using the timestamps of both the reference audio file and the event's audio file.  This option can be useful for situations in which the user has a very long reference audio file with much shorter event files to be synced.  Without pre-syncing based on the timestamps, processing would become prohibitively long.

b. Preview and Adjust.  Once events are selected, AudioSyncR launched, and the pre-sync with timestamp option ticked, this button will start flashing and the "Start" and "Apply and Exit" buttons will be grayed out.  The user must click on  this button which analyzes the file's timestamps and opens the following Timestamp Adjustment dialog.

The purpose of the timestamp analysis is to make sure that all events fall within the range of the reference media file.  If not, the user may adjust the timestamp of the reference file   Note that these adjustments are temporary and do not result in changes to the media files themselves.  The number of events falling before, within, and after the reference file timespan is shown.  The user may then add or subtract, Years, Months, Days, Hours, Minutes and Seconds using the up down boxes.  Once adjustments are made, the user may reset to "no adjustments" as shown above by clicking the reset button 

c. Apply and Exit.  Adjusts the start times of the selected events based on the adjusted time stamps and exits the script.

d. Select Reference Media.  If there are multiple media files contained on the reference track, a drop down list is used to select the media file that is to be used.  If there is only one media file found on the track, the name of that file will automatically be shown.

3. Waveform Sync Processing Options.  Syncing is achieved by a comparison of the waveform from the audio event with the waveform of the reference track.  ASR works best (faster) if the start position of each event is at least “near” its position in the reference track.  The better the initial alignment, the faster the syncing.  The user can adjust a number of parameters that can dramatically affect the speed of processing. The two main parameters are Search Start Range and Search Length which are illustrated below.

a. Auto.  If ticked, the entire length of both the event to be synced and the reference audio track will be searched to find the best match.  Note that this option is NOT recommended for lengthy events and reference tracks due to the potential for long processing times.  For such situations, it is recommended to use the Start Range and Search Length options as described below.

b Start Range .  Search start range defines the position on  the reference track where sync processing begins and ends for each event.  If unticked, the entire reference track will be included in the search which is NOT recommended, unless it is fairly short track.  As shown above, search for a waveform match would start at the beginning of Region 3 and stop at the end of Region 2.

c Search Length.  This parameter defines the beginning part of each event which will be included in sync progressing  and is shown as Region 1 in the above illustration.  If unticked, the entire event will be included in the search which is NOT recommended unless events are fairly short.  The default parameters are set for a start range of 10 sec and an event search length of 5 sec.  These values lead to a total search range of 25 sec.  Processing can be sped up to the extent that these values can be reduced.

d Auto Retry .  This option is ticked by default.  When ticked, the same sync point must be produced on two successive runs.  Although processing time is increased, it does ensure an accurate result.  It eliminates the possibility that the true sync point is not contained within the initial start range and length values set by the user.  It works by doubling the Start Range and Length values on successive runs. 

e.  Events in order .  Selected events are in chronological order.

f.  Detect drift.  If ticked, audio drift  will be detected by performing a sync at the beginning and end of each event.  If the results of these two analyses produce the same sync point, no correction will be applied.  If different, the playback rate of the event will be adjusted which will have the same effect as the user Ctrl-Dragging an audio event.

g. Try quicker .  If ticked, the sampling rate of the temp audio files will be reduced thus speeding up processing.

h. Try harder. If ticked, the reference track will be analyzed by regions based on the length of the selected event or selection loop. 

i. Adjust after first match.  This option should be used ONLY when the user pre-syncs with the files timestamp.  After the first successful match, the start positions of the remaining events are adjusted and the search range/search length values are reduced thus speeding up processing.

j.   Resets Start Range,  Length, and AutoRetry to their default values.

4. Event Options After Sync

a. Move Event to Sync Point .  If selected, the event moves so that the two audio waveforms are synced.

b. Keep Event in Same Location .  If selected, the event remains in the same timeline position.

c. Add Synced Audio as a Take .  If ticked, the audio from the reference track is added as a Take to the event's existing audio.

d. Add Synced Audio to a New Track .  If ticked, the audio from the reference track is added to a new track.  Note that selection of both options is possible.

e. Add Markers at Sync Points .  If ticked, markers will be added at sync points. If Auto Drift is selected, a marker will be added to the end sync point as well.

f. Quantize Synced Event to Nearest Frame Boundary .  Sync points are always computed at sub-frame accuracy which leads to events being moved to positions that are usually not on frame boundaries.  If ticked, event start positions and lengths will be re-quantized to the nearest frame boundary.  By default, this option is ticked.

5.  Temp Folder Location

a. Specific folder location.  If selected, the user specifies the folder where temp files are rendered.  To select a new folder, the folder browse dialog may be opened by clicking the  button.

b. Project Sub-folder.  If selected, a sub-folder named "AudioSync" will be created in the project folder location.

c.   Opens the temp folder in File Explorer.

d.   Clears all temp files from the temp folder.

e. Delete temp wave files upon completion.  If ticked, temp files will automatically be deleted when syncing is completed.  For lengthy tracks and events, it is recommended that this option remain unticked and temp files be cleared upon successful completion of syncing.

6. To abort processing, hold Shift-Escape.  Enables the termination of processing.  It is important to hold these buttons down until processing stops.  If the timeline has been changed, enter Ctrl-Z to undo those changes.

7. Cancel.  Saves settings and closes dialog without syncing.

8. Start .  Begins syncing.