Blackmagic Forum

Hello,
I have a question: what is the best way to synchronize the song being played with the video when shooting a music video?

I've had the problem the last few times that the wave file in Resolve couldn't be synchronized with the recorded audio file from the video.

Is there another solution? How do you do it? Maybe via timecode?

Thank you in advance for your help.

Best regards
Manuel

Sync by waveform in Resolve has been 100% reliable for me for years now, never had any issues unless the in-camera audio was clipping or distorted by wind noise, etc.

Timecode should work well, but be aware of the potential for timecode drift on longer clips.

Manuel,

I assume that you’re recording your audio on a standalone audio recorder and you’re trying to sync that audio using a backup track recorded on your video camera. Correct?

Are you using a traditional camera or a smartphone camera to film? If the latter, which phone?

Set your external audio to 48Khz to match video audio too. I have no problems syncing my F3 but it is set to 48kz 32 bit float.

Hello, thank you very much for the quick answers.
I film with a Blackmagic Pocket Cinema Camera 4k and use an external microphone.
I play the song via a Bluetooth box.

I then pull the film material into Resolve as well as the wave from the original song.
When I go to synchronize using a waveform, the waveforms are not recognized recently.

Synchronizing everything by hand is a lot of work, so I wanted to know how you do it?

Best regards
Manuel

I’m still unclear about your sound recording and filming process. If your process is right, the problem that you’re having should not be happening.

In any event, you can close a slate or clap your hands at the beginning (or end) of filming each clip. Watch this Deity Microphones video. There’s more information in this video than you probably need, but it can’t hurt to know the full process. As the presenter says, you can just clap your hands.



You could also use timecode, but this requires purchasing a Tentacle Sync or Deity timecode box. There are YouTube videos about both.

reim95 wrote:… I film with a Blackmagic Pocket Cinema Camera 4k and use an external microphone.
I play the song via a Bluetooth box.

I then pull the film material into Resolve as well as the wave from the original song.
When I go to synchronize using a waveform, the waveforms are not recognized recently.

Apologies, but I’m not clear what you are doing. If the band is playing a song and you capture that in camera using an external microphone and then you are adding a separate audio in Resolve from a Bluetooth device, even assuming the audio tracks are both 48000 Hz, no song is going to perfectly match from the beginning to the end if you are using two versions of it, as inevitably the timing of playing will have some variations. Each audio track may sound fine separately but not precise to 48000 Hz.

I’ve mixed tracks from multiple takes in a music video completely successfully, but they’re only snippets that work in a short timeframe, not the entire video.

As for sync by waveform, I’ve had that fail. But you can match waveform manually… if both tracks are the same source. As I understand you are using the same song, one audio track recorded from the live performance and trying to match that to an audio track of the same song but recorded from another device. Why?

If you’re the Beatles and working in an analogue mono world, of course the sound engineer could mix different takes on a studio album. But in a digital world recording a 48KHz or even 384KHz, the entire song can’t match end to end.

You need multiple mics (4 mics minimum or more) recording simultaneously to multiple isolated tracks, so you have perhaps a track or two for vocals, one for bass, one for percussion, one for guitars, one for piano, one for strings. Mix as appropriate and duplicate vocal tracks to apply Voice Isolation to enhance vocals that can be lost in the din of all these instruments.

reim95 wrote:Hello, thank you very much for the quick answers.
I film with a Blackmagic Pocket Cinema Camera 4k and use an external microphone.
I play the song via a Bluetooth box.

I then pull the film material into Resolve as well as the wave from the original song.
When I go to synchronize using a waveform, the waveforms are not recognized recently.

Synchronizing everything by hand is a lot of work, so I wanted to know how you do it?

Best regards
Manuel

That wav file is probably 41.1Khz but the audio from you camera will be 48Khz. Resolve will try and sync by sample so they will not line up. You can resample that wav file in a DAW like Audacity etc and then try that resampled wav file in Resolve.

rick.lang wrote:Apologies, but I’m not clear what you are doing.

Great to learn that I’m not the only one who’s unclear about his sound recording and filming process.

He is shooting video of some one maybe miming to music played by a Bluetooth speaker. Then trying to sync the video with the wav file played by that speaker almost certainly not 48khz. Could be 44.1. That will not sync in Resolve.

SkierEvans wrote:He is shooting video of some one maybe miming to music played by a Bluetooth speaker. Then trying to sync the video with the wav file played by that speaker almost certainly not 48khz. Could be 44.1. That will not sync in Resolve.

If that’s what he’s doing, the problem is a lot more basic than his sample rate. The sample rate is beside the point.

Manuel, if you want to use waveform synchronisation, you should be recording via what’s called double system sound.

Your video camera should record both the image and basic audio. The audio can be recorded by the camera’s onboard mics.

You should have a separate audio recorder and a good mic recording, at the same time, the higher quality sound you want to use in the final film.

As Ron says above, the video camera and the independent recorder should both be set to an audio sample rate of 48kHz.

In DaVinci Resolve, you use the basic audio that was recorded with your images, and its waveforms, to synchronize the audio that was recorded with your independent recorder and good microphone. Once the good audio is synchronised, you can delete the camera audio. The camera audio is commonly called a scratch track. It’s temporary, only used to synchronise the “real” audio.

If you aren’t doing this, waveform synchronisation simply won’t work. The camera audio and the independent recorder audio have to be identical. They just differ in sound quality.

If you use a slate/clap your hands (see the Deity video above), you don’t have to record any audio to your camera, unless you want it as a backup. If you want camera audio as a backup, you may want to use a mic or mics on your camera that are better than your camera’s onboard mics.

Why use the camera mics at all? Run the lipsync track straight into the cam and be done. The waveform will be a near perfect match.

Good Luck

Howard Roll wrote:Why use the camera mics at all? Run the lipsync track straight into the cam and be done. The waveform will be a near perfect match.

I was just trying to clarify how waveform sync is used. It’s still unclear, at least to me, what his process is and what he’s trying to achieve as an end product.

reim95 wrote:I film with a Blackmagic Pocket Cinema Camera 4k and use an external microphone.
I play the song via a Bluetooth box.

I then pull the film material into Resolve as well as the wave from the original song.

It sounds like you are doing some form of karaoke recording as opposed to lip-syncing a prerecorded song. For most music videos, the recorded song is played back on speakers and the musicians play and sing along; the camera's mics can be used for the scratch track that is later synchronized to the recorded song (and as was pointed out, the wav file of the recorded song must be at 48kHz for the sync to work in Resolve).

But when you say you use an external microphone, what are you recording with that external microphone? Are you playing a backing track using the Bluetooth box, and then you're singing into a microphone? And where does the microphone go -- directly to your camera or does it go to an external recorder?

Brad Hurley wrote:It sounds like you are doing some form of karaoke recording as opposed to lip-syncing a prerecorded song.

If that's the case I wouldn't expect much success with waveform sync as the camera track would have vocal and the music bed would not. The waveforms would be completely different.

If you're trying (for reasons unknown) to use the camera audio then TC is the way to go. Even if the BT interface doesn't have an LTC out one can generate a TC slug and send it to the camera on the L or R output of the interface.

https://elteesee.pehrhovey.net

Good Luck

reim95 wrote:what is the best way to synchronize the song being played with the video when shooting a music video?

Feed the music directly to the camera, not through a mic.

I can only say what I do. I have the whole band wired direct into a 32 channel Presonus mixer. All the band members use in ear monitors. The speakers for the band's PA system are turned off. You can only hear the singer in the room. That way I get no remix from the live performance. At the beginning of each song I have the drummer hit his sticks together for the beat of the song and so I can capture it with the in camera mics. I then manually line up those four stick strikes between the camera and the final mastered song. Much the same as using a slate.

After lots of us have responded nothing from the OP

Hello, wow, thank you very much for so much support.

So I think that from what I read it has 100% to do with the 48kHz.

I play the finished song, i.e. instruments and vocals, through a Bluetooth box and move my lips to it.

I record the whole thing with a microphone that is connected to the camera. This way I have the original sound of the song to which the lips move.

Then I load the videos into Resolve that have a sound from the day of recording and synchronize it with the finished song that was recorded in the studio.

So that I understand this correctly, the camera records at 48kHz, i.e. the wave must also be 48kHz so that it can be synchronized as a waveform in Resolve.

How does it work that I feed the song directly into the camera via the Bluetooth box?

best regards
Manuel