I recently reviewed an excellent plug-in from Singular Software in Vancouver, Canada. PluralEyes automates the synching of clips in multicamera shoots, analysing the audio waveforms and and achieving perfect synchronisation without the need for clappers or other traditional devices. PluralEyes has won several awards since its release, most recently the Award of Excellence from DV Magazine.

Having been impressed with PluralEyes, I was keen to try their newest software, DualEyes. This program uses the same pattern recognition approach to synchronising audio, but gives it a neat twist. It also offers several other clever tricks that I’ll describe in this review.

 

The Purpose of DualEyes

 

DSLR cameras are being used by an increasing number of video makers because the large sensor dimensions produce highly desirable narrow depth-of-field that is favoured by feature film cinematographers. This superior imaging is extremely affordable but the audio side of many of these HD-capable DSLRs is somewhat lacking. Therefore a common solution is to record video and an audio guide track on the DSLR while also recording a high quality audio track on a separate digital recorder such as a Zoom H4.

 

There’s a lovely twist to all this – in searching for an affordable way to shoot cinema quality video, we have, for the moment at least, forgone the ease of automatically synced video and audio and gone back to the days of the separate audio recording system. This does seem like a retrograde step but I predict it won’t last. Sony’s NEX VG10 shows how a DSLR can be packaged in a video camera’s housing thereby giving the best of both worlds.

 

Imagine you’ve recorded your video on a DSLR and a high quality audio track using a Zoom H4. How do you bring those together? For AVI and MOV files, DualEyes allows you to sync and interleave the high quality audio with the original video, without re-rendering the video. The result is a new clip, ready for editing, that has the original quality video synced with your high quality audio.

 

Using DualEyes

 

The basic procedure is simplicity itself. You load the video files (AVI or MOV) and the matching audio files recorded on the Zoom. In the first instance you can try synching without getting fancy. Just click on the scissors button and DualEyes does the rest. The result is a new video file ready for editing.

 

Given the complexity of what the software is actually doing under the bonnet, there are a number of powerful options that can be tweaked to improve the results. These options are clearly explained in the help files which are reproduced here. 

General Strategy for Syncing

First try to sync with none of the options checked. The Sync Options will say (none) in that case. If some clips don't sync and you are sure they should, consider whether the following apply to your project:

• If the audio varies a lot between the clips, choose the Level Audio option. DualEyes will do some extra processing to compensate. The results are almost always better but it takes a little longer.
• If you don't have too many clips, try the Try Really Hard option. This tells DualEyes to do a lot of extra processing. It can often resolve difficult sync situations but it can take a lot of time, especially if there are a lot of clips that do not sync with each other. But if you don't mind waiting, try it out.

Correct Drift

Timing differences between audio and video can cause drift, which manifests itself as audio and video being synced on one segment of the video but unsynced in a different segment. The Correct Drift option corrects this so that everything is in sync all the time.

Level Audio

This option is useful when the audio levels vary a lot between clips. This can happen, for example, in an interview where the on-camera mic is close to one person talking and the audio from the other person comes from a lavalier mic. If you choose this option, DualEyes will do some extra processing to compensate. It is almost always safe to use this option, but it takes a little longer.

Try Really Hard

This whimsically-named option tells DualEyes to spend extra time trying to find the sync. It can take 5-10 times as long so you will want to use it only on the most stubborn sync problems or when you are willing to let it run for a long time. If you can tolerate the time penalty, this can be very effective.

Infer Chronological Order

It is often the case that the names of the media files, when sorted alphabetically, are in the same order that the recordings were made. If so, then checking this option will give a hint to DualEyes that will help it sync faster and more reliably.

Use Existing Extracted Audio

DualEyes extracts audio from each media file to a temporary file. Turning this option on will save time if you need to re-run DualEyes on the same project. It will re-use the file that has been previously extracted. If DualEyes can't find the file, it will extract the audio.

Replace Audio for MOV and AVI files

DualEyes can create a new file which contains the video from the original clip and the synced audio for MOV and AVI files. The video is not re-encoded, but the compressed data is simply copied from the original file resulting in no loss of quality.

Reset

This is a quick way to uncheck all the options.

 

The ability to replace the audio on a file without re-encoding the video clearly has potential applications beyond the original intention of the software. You may, for example have an old video in which the audio needs repair. Normally you could repair the audio using software such as Sound Forge, but once fixed, you’d have to re-render the whole thing, thereby degrading the video slightly. By using DualEyes, that video degradation can be completely avoided.

 

Another powerful function of DualEyes is its ability to correct audio/video drift. To test this, I rendered out an avi version of a 5-minute video clip (DualEyes AVI render), then rendered the audio as a .wav file. Using this to represent audio recorded separately, I stretched this track by about five frames to simulate drift (5 frames drift.wav). I then let DualEyes try to work its magic, selecting just the ‘Correct Drift’ option.

 

DualEyes created a new temp folder, analysed the drift in about 20 seconds, and produced a new wav file called DualEyes AVI Render_avi_from 5 frames drift_corrected.wav. This new file was named in the Output field of the main window, making it easy to locate in the temp folder.  

 

Finally , I tried the same thing, but using both ‘Correct Drift’ and ‘Replace Audio’ options selected. Understandably, this process took much longer, completing the newly interleaved clip in about 8 minutes. As expected, the audio was correctly synced and video quality was unaltered.

 

Conclusion

 

Brilliant! Once again, Singular Software has identified a real need and addressed it elegantly. The software is intuitive to use, the labelling of newly created files is logical, and the whole process is rapid and efficient. Although designed with DSLR videographers in mind, this clever software will find many other uses and, like PluralEyes and Presto before it, will be a ‘must have’ item in your NLE toolbox.

 

Auscam Online ratings

 

Ease of use:	9
Features:	9
Performance:	10
Documentation:	9
Value for money:	9

 

We liked:

Intuitive interface and clearly explained options, speed of processing, ability to replace audio without re-rendering video in AVI and MOV clips

 

We didn’t like:

Nothing to dislike

 

Vendor:

Singular Software

www.singularsoftware.com

 

Price:

RRP $149 USD

20% discount until October 30^th 2010

 

 

 

By David Smith

Dr David Smith is a physiologist-turned-film maker. David was Associate Producer of the IMAX feature Australia Land Beyond Time and was Senior Researcher on the ABC TV series Nature of Australia. He wrote and hosted David Smith's Earthwatch on ABCTV and was 'resident zoologist' on the Don Lane and Bert Newton Shows.

In 1987 David set up his company, imaginACTION pty ltd (www.imaginaction.net.au) and has sinced written, directed and/or filmed numerous documentaries and educational multimedia projects. He has also written six books, including two Penguin eco-thrillers. Over the past five years David has moved towards medical and health-related projects, including trauma surgery, schizophrenia and emergency medicine.

David is a Fellow of the Royal Society for the Arts and a professional member of the AFI and has always been keen to share his knowledge, especially with young budding film makers. David can be contacted at david@imaginaction.net.au.

 

Please login to post your comments.