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Cannibal Shogun
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Audio sync drifting in rendered clips

Aug 9, 2012 2:41 AM

Tags: #adobe #pro #audio #sequence #5.5 #render #sync #premier #synch #drifts

I'm using Premiere Pro CS5.5 on a PC running Windows 7, 2.80GHz Intel Core i7 CPU, 6GB RAM, 64-bit OS.

 

I am working on an interview I shot with 2 Canon DSLRs, a 500D and a Rebel T3i, using audio captured with an M-Audio Microtrack II. The audio was edited down in Premiere then rendered out and handed over to a third party to be cleaned up in Pro Tools. The length of the edited interview is just short of 4 minutes.

 

When I preview in my Premiere timeline the audio is synced but when I render out the clip the audio drifts so that it starts already out of sync by a frame or two and by the end it's clearly off by a lot. I'm not sure how to proceed since the audio looks more or less perfect in my timeline.

 

I'm really hoping somebody has some suggestions as this project deadline is tomorrow, I'm supposed to be just making minor fixes at this point but suddenly I'm dealing with an issue that has totally broken nearly half my video.

 

Thanks

 
Replies
  • Currently Being Moderated
    Aug 9, 2012 2:58 AM   in reply to Cannibal Shogun

    What are your project/sequence settings, the formats you're exporting to and the frame rates of the EOS footage? This type of thing can sometimes happen if the audio sample rate is being changed at export, but the obvious question to begin with is which track is actually correct - is the audio running slow or the video running fast? How do the lengths of the exported footage compare to your sequence?

     
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    Aug 9, 2012 6:31 AM   in reply to Cannibal Shogun

    in other sequences I have captured video game footage that is 60fps too

     

    Sorry, that is not possible. Capturing only works over firewire from a tape based camera and that never is 60 fps. Please get your terms and phrasing correct to help us understand you in order to help you. 41.1 KHz is a very weird format. 44.1 is possible but not advisable. 48 KHz is the regular format. NEVER  use QuiRcktime if you can avoid it. It causes serious gamma shifts and reverts your 64 bit environment to 32 bit.

     
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    Aug 9, 2012 8:19 AM   in reply to Cannibal Shogun

    PrPro should be able to Conform the 44.1KHz material to 48KHz, though I wonder if the BM CODEC used might be an issue?

     

    Good luck,

     

    Hunt

     
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    Aug 9, 2012 8:53 AM   in reply to Cannibal Shogun

    I use a blackmagic intensity to capture game footage straight from XBox 360 console via HDMI.

     

    That is not capturing but ingesting. Confusing these terms can lead to misunderstanding. Like saying to your car mechanic, when I drove here versus when I swam here.

     
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    Aug 9, 2012 9:24 AM   in reply to Cannibal Shogun
     
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    Aug 9, 2012 9:46 AM   in reply to Harm Millaard

    Cannibal Shogun is perfectly correct, the term 'capturing' is standard terminology for the process of recording computer screen images using an application other than the one drawing the screen data (Adobe use it for that exact meaning, it's why Captivate is called Captivate and not Ingestivate). The word has a slightly different meaning to those working in tape, but the definition of 'capture' in Harm's glossary still applies to what Cannibal Shogun is doing with his XBox, as the console is behaving as the camcorder or DV deck, sending picture frames to a device which encodes them into digital video.

     

     

    ..and if people don't start acting polite and talking about the topic in question rather than attacking each other, I'm locking the thread.

     
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    Aug 9, 2012 10:08 AM   in reply to Cannibal Shogun

    What application did you use to Resample the Audio? Have you tried any other codec export besides Quicktime H264? Any time you have audio drift over time like that which gets worse as you progress is almost always a sample rate issue /re-sampling between 44.1K and 48K. Those 2 sample rates are the only ones so close that the issues starts as a frame or 2 and gets worse each second. Do you only have the 1 audio file that you had to resample in the sequence your exporting? Did you by chance select Non Drop Frame in your project sequence or export settings?

     

    Eric

    ADK

     
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