FPV audio sync

Sync FPV footage to outside audio, right through the prop noise

A GoPro on an FPV drone records four motors a few centimeters away and barely any music. SyncFPV was built to hear through them. It lines every flight up with the festival board, a field recorder or any outside audio, and tells you how sure it is about each one.

Audio

Any outside recording: board, field recorder, lav, mixer

Clues used

Camera mic, slate, file metadata, the whole night

Result

Every flight placed, rated High, Medium or Low

Free version

One camera to one audio file. Studio adds multi cam and festival sync

Why FPV footage is hard to sync

General sync tools compare the sound two cameras heard and slide them until they match. That works when both heard the room. A naked GoPro on an FPV quad hears props first and the show a distant second, so those tools find nothing to match, or the wrong thing.

Electronic music makes it harder. A set repeats the same bars for minutes at a time, so one short clip can match the board in many places that all sound right. Picking one at random puts the drop in the wrong spot.

How SyncFPV places every flight

All four clues go into one answer per flight. Each flight comes back rated High, Medium or Low, so you know exactly which ones to preview and which to trust.

Two clock checks instead of slating every flight

Before the first set and after the last one, film the SyncFPV Slate’s clock check for 10 seconds with each GoPro. SyncFPV finds those two clips, measures how far each camera’s own clock is off and how much it drifted during the night, and gives every flight its true time. No flight needs its own slate. Slate one anyway when you want the artist’s name on the picture.

GoPro Labs firmware makes this easier, because Labs sets every camera’s clock from the slate’s code, but it isn’t required. Without it, set the clock in Quik and the two checks measure the rest.

What audio to bring

• From a festival board: one recording per artist set, or one of the whole night. SyncFPV cuts a full night into sets by the lineup, finding each changeover in the sound.
• WAV if you can, the raw files, started before your first flight.
• The recorder’s clock doesn’t have to be right. The flights tell SyncFPV where the recording sits.
• A setlist is optional. Add one and the songs get named on the timeline and in the file names.

Not only festivals

Festival board audio is the hardest case there is, which is why the analyzer started there. The same engine syncs any outside recording: a field recorder at a car meet, a lav at a wedding, a mixer at a game, a band’s multitrack. In Studio, festival and multi cam sync lines up every camera of the day on one timeline and splits it by set and by song.

Quick answers