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Old 01-20-2016, 12:39 PM
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reichman reichman is online now
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Default Bounce to Quicktime sync PT12 vs. QT Pro

I've been so busy, I haven't tested PT12's bounce to Quicktime function for sync accuracy. It looked pretty good to me, so when a client gives me an H.264 video, I bounce the mix back to that video in PT and send it to the client for review. (Actual show laybacks go to a dedicated facility.)

BUT, there is a discrepancy:

1.) marrying the audio and video in QT Pro, reimporting to PT session = 0 sample time shift.

2.) Bounce to Quicktime (H.264) in PT12.4 = 934 samples late (a little less than half a frame).

Why?
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Old 01-20-2016, 03:54 PM
dieffe dieffe is offline
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Default Re: Bounce to Quicktime sync PT12 vs. QT Pro

I don't know if something changed, but there was a problem with the delay compensation: the QT bounce was off by the same amount of samples as your ADC in the session. It may be due to that thing
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Old 01-20-2016, 03:58 PM
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Default Re: Bounce to Quicktime sync PT12 vs. QT Pro

Not sure about ADC. My total session ADC is longer than that, and I did a test bounce of an audio file with the compensation set to blue (bypassed), and still the same thing. I need to perform the test with DNxHD video codec... lots of variables, but a little disappointing since I really don't like having to use QT Pro or some other external app to marry audio and video.

Of course, moving the mix back 934 samples for the video export works fine.
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Old 01-20-2016, 10:43 PM
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Default Re: Bounce to Quicktime sync PT12 vs. QT Pro

I have noticed similar latency exporting AAC-LC audio and importing it back.
Maybe it's due that H.624 codec, MPEG-4 audio stream usually is AAC-LC and maybe PT video engine doesn't handle it very well. I use MPEG streamclip for DNxHD creation and HandBrake for H.264 creation. It's one more step to go, but i had no problems and have noticed that it's bit faster than using PT video engine only.
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Old 01-21-2016, 06:56 AM
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Default Re: Bounce to Quicktime sync PT12 vs. QT Pro

Quote:
Originally Posted by reichman View Post
I've been so busy, I haven't tested PT12's bounce to Quicktime function for sync accuracy. It looked pretty good to me, so when a client gives me an H.264 video, I bounce the mix back to that video in PT and send it to the client for review. (Actual show laybacks go to a dedicated facility.)

BUT, there is a discrepancy:

1.) marrying the audio and video in QT Pro, reimporting to PT session = 0 sample time shift.

2.) Bounce to Quicktime (H.264) in PT12.4 = 934 samples late (a little less than half a frame).

Why?
Can you visually spot less than a half frame? Will the viewers ever going to notice that, when watching on their tvīs, tablets, mobile phones, streaming on YT or whatever? I mean, the process should be sync accurate in the first place, I agree. I can hear 1 ms diference in a music edit (if I made of course),
but I honestly canīt spot a half frame out of sync with my eyes.
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Old 01-21-2016, 07:05 AM
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Default Re: Bounce to Quicktime sync PT12 vs. QT Pro

Quote:
Can you visually spot less than a half frame? Will the viewers ever going to notice that, when watching on their tvīs, tablets, mobile phones, streaming on YT or whatever? I mean, the process should be sync accurate in the first place, I agree. I can hear 1 ms diference in a music edit (if I made of course),
but I honestly canīt spot a half frame out of sync with my eyes.
Context matters. After I spend an hour or two with a director, nudging syllables by quarter-frame increments to improve lip-flap on a close-up, I feel like an idiot sending a video that's off by half a frame. Would I notice a 1 frame offset on 70% of the shots? Probably not. But the other 30% I might.

And when I'm watching TV in my living room, I get distracted by poor lip flap, or obvious ADR. It takes me out of the engagement with the story.
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