BWF2XML in FCP 6.0.5

[Bouke Vahl]

Andreas will correct me if i’m wrong, but here is my take on it:

BWF2XML is there to fix playback speed issues. It has nothing to do with automatic syncing, nor TC reading.

FCP reads TC info on BWF just fine.
BUT, to be thechnical correct, BWF does NOT have TC, it has another timestamp that is dependent on sample rate, giving it room for error in 29.98 / 30 / 23.976 / 24 fps workflows.
And that can bite you if you do not know the theoretical background.
It really isn’t that difficult, but with high school math still will take you a day to grasp it.

(and yes, automated syncing is possible, check the FCPauxTC reader on my site. But DO READ ABOUT BWF SPECS)

Bouke

https://www.videotoolshed.com/
smart tools for video pro’s

[Ryan Krickow]

This is what Andreas had told me in the past…

“FCP 6 does use the current project settings to interpret the playback speed and the timecode. So be very very careful with that. It’s always a good idea to create a project with a setup you need match the easy setup and relaunch Final Cut. Then import all your BWAVs, open the project they should belong to and drag the files over. Final Cut will cache the BWAV settings from the “Import Project” and write to your work project. So if you don’t import all BWFs in one day, this works easily. If they come a day by day you should do this procedure each day.

Another thing with BWAV files, they don’t have a Quicktime Timecode, which is used in FCP to sync clips. You will see a timecode though in FCP with BWAV files, it based on the audio timestamp and is generated on the fly.
If your work includes synching video with external audio you can’t do that by timecode even if you spent money and time to keep cam and audio running running in sync on the set. Same is valid for multiclips and for a certain extend also for subclips.
Be careful when you media manage projects.

That’s why there is BWF2XML. It takes the audio data and puts them into QT wrapper including a matching QT timecode.”

It has taken me a while to wrap my head around this issue since I keep getting conflicting responses from people regarding the use of BWF2XML. Some say it isn’t necessary anymore and others tell me that they use it. I’ll check out your website, and I really appreciate your help. Thanks, Ryan

[Andreas Kiel]

Bouke is not totally correct.
It looks like FCP can read interpret BWAV timestamps and correctly creates a SMPTE time code, but this in many cases only looks like as the widely used Sound Devices recoders and Aaton recorders always buffer back the recording to full seconds. It’s different with Zaxcom.
Look at the Final Cut manual pages 325-327. It describes somehow how the SPMTE time code is mapped on the fly to the BWAV file. This time code effect can be used in Final Cut Pro to sync audio and video, but this is not a stable sync when clips are merged, subclipped or multiclips are created out of those clips.

As Bouke stated correctly the QT wrapper for a BWAV file assigns a stable playback instruction to the file which is independent from Final Cut setups. Also no (wrong) time code caching will happen any more in Final Cut.
Bouke’s AuxTC reader finally does the same thing when the audio is merged with the video.
In both cases the audio how does have a QuickTime time code track, which does allow to keep AV in sync even trough inserts, media management and other XML roundtrips.

Andreas

Spherico
https://www.spherico.com/filmtools

[Ryan Krickow]

Thank you both for the info! May I ask what exactly you mean when you say “stable sync” in the following sentence… “This time code effect can be used in Final Cut Pro to sync audio and video, but this is not a stable sync when clips are merged, subclipped or multiclips are created out of those clips.” I’d like to merge all my audio tracks in the beginning before I start cutting, in that case should I use BWF2XML or AuxTC Reader in order for there to be “stable sync” and if I don’t use either of the programs what will happen? I would appreciate it if some third parties would provide info from their experiences with BWFs and FCP 6.0.5. Thanks again, Ryan

[Andreas Kiel]

Ryan,

Both Bouke and me have given you all infos you need.

Maybe you don’t need fcpAuxTC or BWF2XML, but both of them are like afire insurance – maybe you don’t need it, but in case of fire you’re happy to have it.

Andreas

Spherico
https://www.spherico.com/filmtools

[Ryan Krickow]

I really appreciate all your help, thanks! Ryan