Topic: iPhone Timecode with Sound Devices MixPre Series

[vantheman]

I’ve never dealt much with video but I’ve suddenly found myself recording some open mic sets locally. What I’m trying to do is use a iPhone as a rec trigger for the MixPre6ii so that timecode is synced. This way, every performer who already has an iPhone can connect to my system during recording, and then transfer the video to me later where I can quickly add my audio track.

Didn’t see any related posts on this board, so I wanted to see how people solve the problem here.

[rastasean]

You want others to connect to your recorder so that the audio is synced? I think that would depend on the camera app the people are using on their phone.

Take a look at Black Magic's camera app: https://www.blackmagicdesign.com/products/blackmagiccamera
It talks about using a timecode generator with the camera app, but that would mean everyone would need to download and use that app.

[morst]

Didn’t see any related posts on this board, so I wanted to see how people solve the problem here.

I sync in post.
Get the video ready visually using the original scratch phone audio, then once the video part is finished, export the exact phone audio (you need to make it the length of the final product with end fades if any for this to work).
Over in your audio workstation software, import this exported audio into the project which has the good replacement audio.


Line up near the front. Mark that spot (I call it SYNC I) as well as the spot where the phone audio begins for that (I call that SYNC I START PHONE)
Then do the same near the end of the scratch audio. SYNC II/ SYNCII Start.
Now you can measure the differences, and plug those numbers into my spreadsheet, to find the speed change details you need.
Do the speed change on your audio (BE SURE TO DO THIS IN A SEPARATE TRACK or separate project, or undo afterwards so you don't trash your audio project)
and export that.


Back to the video workstation.
Import this new fixed audio, and replace the old audio.
Presto!


I guess a way to keep the audio from being resampled would be to duplicate or omit some video frames, but that's not something I've tried.


That spreadsheet is here. I don't allow public "write" access so just download it to your own sheets account, or load it into your fave spreadsheet app.
https://docs.google.com/spreadsheets/d/1pQGfYwPgBFFzcY5m6aRj-Zbu9HsRumLy-tJB1d8Eufg/edit?usp=sharing


Hot tip- audio can lag behind video, and our brains just think we are far away watching it, and waiting for the sound to arrive.
If video lags behind audio, it is disconcerting, if not unsettling!
Therefore, err on the side of slightly delayed audio.

[vantheman]

Whoops, missed these replies.

So the original idea was that if everyone is using the same app/system to sync timecode with my deck, then they could send their video to me after the night is over, and I could conceivably automate the entire process via scripting and use my audio with some automated mixing/mastering moves to produce video and audio quality good enough for social media.

Morst I’ve been meaning to check out your spreadsheet and this is a great opportunity to do that. Right now it works fine just eyeballing it, and it’s been fine. The Tentacle devices might do what I envision in my mind but I’m not looking to sink that much money into a solution I’m not getting paid for.

[morst]

Morst I’ve been meaning to check out your spreadsheet and this is a great opportunity to do that. Right now it works fine just eyeballing it, and it’s been fine.

If you are lucky to have two machines with very similar clocks, lining them up anywhere might work fine.
You also might be able to get away with short pieces that way but longer might require squash-stretch.
I know of at least one taper on here who has a magic pair of recorders.

[rastasean]

You may like this video about timecoder from Curtis Judd: https://youtu.be/jJWe_bn9BlQ

Timecode would sync things at the start/beginning of the recording, but there can/will still be drift by the time it ends if it's an hour or longer.
In that case, he recommends having the cameras and mics connected together to prevent the drift.

I suppose you could stop/start recording audio and video in between songs to prevent the drift, but if the phone/camera isn't yours, may be harder to do that.

Why is there a need to have separate cameras/phones recording the event? Couldn't you take a camera and feed the audio from your mixpre into the camera so it would be in sync?

You probably want to solve these problems/questions before wondering how you will solve the automation thing.

[vantheman]

Why is there a need to have separate cameras/phones recording the event? Couldn't you take a camera and feed the audio from your mixpre into the camera so it would be in sync?

No need, but how it currently works is every performer sets up their own phone/storage wherever they want to record their own set. So a couple things are at play here. One is people are already using this workflow and now since I since I entered the fold there's one additional step, if they choose, of sending their video to me for mixing. Second, if I already had a legit camera setup that could record several continuous hours of video and that handles timecode out of the box, I would just be doing that instead of starting this thread. I'm not interested in investing more money in a time consuming volunteer gig, and I like the fact that I'm not responsible for capturing video.

Setting up 2 mics on stage, mixed with sbd, is easy enough, and each set is about 20 min long, so there's some drift but it's minimal. With a few minutes of work you get a final product that isn't perfect but is much better than onboard iPhone mics. Good enough for social media, and fixable with added effort. Timecode is the missing piece that would make this easy to automate.

[willndmb]

If you are using Final Cut Pro
Load the files, audio and video
Name the angles. I name audio A and video V. If there are multiple sources say a camera that’s full stage and one that zoomed in video vZ and vC
Use the built in create multi cam clip and let FCP li e it up for you