Export track 2 audio out of sync no luck deleting renders

[Richard Herd]

[Rosie Walunas] “It’s got to be some stupid little thing in Premiere.”

I disagree, here. It is not Premiere’s fault, here. And I feel it’s the editor or Post Production Supervisor’s job to make sure production delivers the correct stuff to editorial. It can be a tricky situation, and political, because the boom pole operator may not exactly be qualified to deliver material. I’m sure they are a great on set, though.

I checked the manual, and it is not possible for the C300 to record two different frame rates in the audio channel simultaneously. https://www.manualslib.com/download/275688/Canon-Eos-C300.html

This means, the lav mic was probably a wireless gadget plugged into the camera so it is sync’d properly. But often a boom pole operator records to a field recorder, of which there are many types.

Then production then delivers the camera data and the boom-data to the DIT, who muxes and delivers for post.

It is the DIT’s responsibility to deliver proper material. She or he should have noticed the error at that time, and then (1) notified the boom pole operator to change time base, and (2) re-sampled the audio for editorial BEFORE delivering to editorial.

This appears to be a relatively large mistake, and you are the only one who knows. So that gives you some power to explain and fix. I hope you feel you can bring it up. Having been down this path I can tell you that these conversations are not happy win-win conversations, but they need to happen. Politely and professionally, quickly to the point, with screen grabs. The fact is: (a) they delivered the wrong audio frame rate and (b) that will add significant time to post production. In effect, their mistake has negated the technological advantage of file based recording, and you (generally speaking) have to recapture all of the audio, as if it were a DAT recording, and then sync it all to picture, screen, create subclips, screen the subclips checking aud1 and then aud1, and then, after all that, finally start telling the story.

I feel your pain. Soooooo sorry. 🙁

If you haven’t already, try asking in the Premiere Pro forum and the Art of the Edito forum. They may have a quick fix I don’t know about (but would also like to know).

[Rosie Walunas]

Hm. It’s not possible to plug a wireless lav and boom – like a shot gun mic into the C300? I assume that’s what they did.

This is such a small team that it’s just two camera people who are also the producers and everything in between.

Why would everything play in sync in Premiere and even in FCP (at 29.97) if the audio rates burned on to the clip play in sync? It’s only on the export in Premiere that it falls apart.

I really appreciate this info though. They’re kind of getting fed up with me about this clip conversion.

[Richard Herd]

[Rosie Walunas] “It’s not possible to plug a wireless lav and boom – like a shot gun mic into the C300? I assume that’s what they did.”

You can–and that’s a really good practice! You just can’t record two separate frame rates. And because you have two separate frame rates, they have done something that either they don’t know what they did, or are trying to hide it and blame you.

[Rosie Walunas] “Why would everything play in sync in Premiere and even in FCP (at 29.97) if the audio rates burned on to the clip play in sync? It’s only on the export in Premiere that it falls apart.

Maybe this will help? https://library.creativecow.net/articles/devis_andrew/Premiere-Pro-CS6-Basics_71/video-tutorial

What if you try this:

[Rosie Walunas]

Hi again. I’m not sure I’m conveying what’s happening very well.

I have C300 footage, lav on track 1, boom on track 2. Recorded at 29.97. All is okay, plays each track fine and in sync. Even when transcoded at 29.97.

I Import the clips into Premiere, interpreting them as 23.976, adjust speed for proper 23.976 playback, and everything plays just fine in the timeline, audio is in sync.

I send my timeline to Encoder to export, export settings okay and match my timeline.

Export is complete, open QT file to listen – and the boom track falls out of sync!

If I try to trick Premiere and compensate for this drift, unlink, adjust boom audio speed in timeline, export, it just changes the pitch of the boom track.

I understand the track layouts and they are as I want them.

How could it be possible that they recorded the boom as a different rate have it be attached and part of the raw camera contents and the lav track is just totally fine?

[Richard Herd]

I admit I have never heard of this problem before. I think the person who delivered the files to you made a mistake with their timeline options and export. If you want, I have some time today, I can check out a file. I can be contacted at gmail: richardmarkherd@gmail.com

[Jp Pelc]

What are your export settings? H.264 has a lot of sound sync issues. Usually it is just a frame or two, sometimes it is a bit more. That is a problem as the C300 shoots to h.264 (side rant: it’s ridiculous that a camera at that price shoots to such a terrible raw codec, but obviously you are stuck with it).

So basically the raw footage could be going in and out of sync by a few frames within your timelines, then if you export to h.264 it can be swinging back and forth in either direction by even more frames.

[Rosie Walunas]

The C300 is shoots XDCAM 50 natively and that’s what my seqs are. When sent to Encoder I am transcoding the codec to Pro Res 422 HQ. No h.264. It’s more than frames off – try seconds.