Sync all over the place

[Paul Harb]

Hoping someone else could chime in here, Ive been reading that others have had this issue as well, but those were dated back in 08 soooo….not really current info that I can find. I did notice that my timeline settings were set to 24bit I think, I changed that to 16bit as the track is an AIFF not camera audio. Its a music video.

Paul

Paul Harb-Producer/Director
Wrong Beach Multimedia
Dual 3.2 GHz Quad/10.5.5/8GIG RAM/FCP 6.0.4/QT 7.5.5

[Gary Adcock]

[Paul Harb] “Hoping someone else could chime in here, “

I did not respond because there is so much info missing to answer your question.

There is NO mention what kind of audio you are using and where did it come from?

what is your workflow, from camera into FCP
If you did, which app did you transcode with and which OS version is the camera on?

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows for the Digitally Inclined
Chicago, IL

https://blogs.creativecow.net/24640

[Paul Harb]

Sorry, I thought I did. The audio is a track NOT from camera, it is an AIFF that is 48k 16bit audio. This is a music video. We shot the RED cams at 4k 23.98…the track was used as playback. I used REDRUSHES to transcode the R3D files to ProRes 422 HQ 23.98 1080×1920.

Now, this is a random thing. Sometimes its out, Ill stop it play again and then it will go back in sync at the same spot that was just out….so Im not sure how it could be some drift due to frame rate/ audio sample rate even though thats the only thing I can think of unless its something with the Kona..I dont know.

THks,

Paul

Paul Harb-Producer/Director
Wrong Beach Multimedia
Dual 3.2 GHz Quad/10.5.5/8GIG RAM/FCP 6.0.4/QT 7.5.5

[Gary Adcock]

[Paul Harb] ” I thought I did. The audio is a track NOT from camera, it is an AIFF that is 48k 16bit audio. “

Have you bothered to check to see that FCP wants 48K 24bit audio and that might have something to do with your problem?

that along with any gaps or empty spaces in your timeline can cause the audio drift you describe-

it’s a settings problem so try rendering a “mix down” for your audio, that will fix it until you edit the timeline.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows for the Digitally Inclined
Chicago, IL

https://blogs.creativecow.net/24640

[Paul Harb]

HEy Gary,

Whats with all the hostility???? The timeline WAS originally set to 24bit 48k and it was drifting all over the place. Why would gaps in the timeline create a drift randomly that is there one minute and then if I play the same spot again its in sync? I will trying mixing down my the AIFF file to 24bit as you say and see if that makes a difference. This is a new workflow for me, so you might cut me a little slack…or not.

Paul

Paul Harb-Producer/Director
Wrong Beach Multimedia
Dual 3.2 GHz Quad/10.5.5/8GIG RAM/FCP 6.0.4/QT 7.5.5

[Mark Spano]

Sounds similar to a problem I had a long time ago with a KONA 3 card. It would start playing with video and audio in sync and slowly drift out. Turned out that the card was not in the correct slot in the Mac Pro. Figure out which cards you have and what slots they belong in – AJA has a primer on their site to tell you where the KONA belongs. It might be in a lower performing slot than necessary and therefore unable to handle the throughput of an HQ sequence.

[Gary Adcock]

[Paul Harb] “Whats with all the hostility????”

the hostility started with the “Nobody” response to your own request.

“This is a new workflow for me, so you might cut me a little slack…or not. “

The needs for FCP do not change because you choose to not follow them. FCP always wants 48k 24bit audio regardless of where the audio ( and or video) came from.

the Mixdown I was talking about is a render inside of FCP.

you are working with audio that is not in spec for real time playback. That means that it needs rendering to playout, gaps in the timeline mean that the render jumps to the next clip to begin rendering whether you have video or not. so the blank areas of your timeline are exacerbating the issue of your audio not being correct.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows for the Digitally Inclined
Chicago, IL

https://blogs.creativecow.net/24640

[Paul Harb]

So your mad that I asked if anyone has run into something similar? Maybe you need to take a deep breathe.

I have always used 48k 16bit audio….not sure Ive ever used 24bit audio….your telling me you always use 24bit audio on your video projects? I have not.

Paul

Paul Harb-Producer/Director
Wrong Beach Multimedia
Dual 3.2 GHz Quad/10.5.5/8GIG RAM/FCP 6.0.4/QT 7.5.5

[Paul Harb]

Hey Mark,

This to me makes more sense than Gary’s 24bit statement. He is saying that my setting are screwed up and I should be using 24bit audio? Im not sure I understand this. Like I said the sync issue is random and fixes itself when I stop and replay the same section, I will call AJA and see if they can help me, thks for the response.

Paul

Paul Harb-Producer/Director
Wrong Beach Multimedia
Dual 3.2 GHz Quad/10.5.5/8GIG RAM/FCP 6.0.4/QT 7.5.5

[Walter Biscardi]

[Paul Harb] ”
I have always used 48k 16bit audio….not sure Ive ever used 24bit audio….your telling me you always use 24bit audio on your video projects? I have not.”

FCP defaults to 24bit audio. This is what you should be using at all times, as Gary says. In order to run 16bit audio you have to manually change the FCP default.

Digital audio is 24bit. If you’re running 16bit audio, you can run into the very issues you have described and which Gary has already addressed in his answers.

Look at any Sequence Preset in FCP. They’re all 24 bit audio for a reason.

Walter Biscardi, Jr.
Editor, Colorist, Director, Writer, Consultant, Author, Chef.
HD Post and Production
Biscardi Creative Media

“Foul Water, Fiery Serpent” featuring Sigourney Weaver coming soon.

Blog Twitter Facebook