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13
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Last Post
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Jan 2, 2009 5:58 PM
by: DanYork
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Posts:
483
Registered:
Sep 2, 2004
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Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 3, 2008 2:30 PM
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Gear: Macbook Pro (early 2008 model) - 2.4gigs cpu 2gigs ram - all the latest updates... no other applications running during the test
Hi folks. Currently I am having a latency issue when trying to record directly into iMovie using the built-in microphone and iSight camera. Basically, the video seems 5 - 7 frames late to the audio. I found that a good way to demonstrate this issue was simply doing a few handclaps as a test.
This is a quick handclap test displaying some video latency during recording with the iSight camera in iMovie 08.
- Just download this link — and import it into iMovie 08 - Here is a link to a zip file that you can import into iMovie 08 - It's 2.5meg - .m4v export - Also it was recorded as standard format and audio midi setup app: audio was set to 44.1:
http://www.brainbeast.com/37/clap-1-large.zip
- Play from beginning. As soon as you hear a clap sound — pause with the space bar - then back up before the clap with the left arrows
- Then click the right arrow several times until you hear the beginning of the clap sound ( This is the audio: start frame)
- Now — you will notice the video still has an open hand. At this point click the right arrow, counting as you go several times until you see the hand close. This is the amount of frames that the video is late to the audio. For me it seems to be an average of about 5-7 frames late.
Unfortunately iMovie 06 nor QuickTime will not scrub audio as you go frame by frame with the arrow keys so you cannot test it there. If you have some other application such as final cut Pro, you could test it with that.
! IF YOU WOULD LIKE TO PERFORM THE TEST YOURSELF:
- Just record a new movie in iMovie 08 - using the built-in mic and i-Sight camera — and see if it is also slightly out of sync
Note: to be as fair as possible — I did a slow handclap ( in order to not challenge the frame rates) - also, in order to get the maximum volume I used an open palm ( clap on the palms with your fingers spread out as you can see I did.)
Please let me know if this latency appears to be the same for you as it does for me.
Q: Is it just my machine or does it happen to you too?
Q: Does anyone know a way around this latency issue?
Q: Does anyone know if Apple is aware of this latency issue?
MBP 2.4
Mac OS X (10.5.5)
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Posts:
483
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Sep 2, 2004
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 3, 2008 5:57 PM
in response to: Rev Dave
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I might also suggest that if anyone wants to do the test - try clapping from about 12 inches away from the camera (and slowly as described).
Macbook Pro 2.4
Mac OS X (10.5.5)
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Posts:
1
From:
Fort Worth, TX
Registered:
Dec 3, 2008
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 3, 2008 8:30 PM
in response to: Rev Dave
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iMovie 08 seems to scrub audio just fine, so the whole test can be done there.
I don't know that it is surprising that audio/video are out of sync, since it seems the main purpose of the camera in the Mac Book Pro is for video chatting--and it takes longer to process the video, but they probably didn't want to delay the audio to match the video.
To me the real question seems to be, is the latency amount consistent throughout the video clip? If so, a quick slide over of audio in FCP solves the problem.
MacBook Pro
Mac OS X (10.5.2)
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Posts:
12
Registered:
Aug 21, 2006
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 4, 2008 9:09 AM
in response to: Rev Dave
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I had a siimlar experience importing video from VHS. I was capturing my son's childhood videos througha Firewire conversion box. What I experienced was variable drift over the course of the rpogram as I could not in fact nudge the audio to line up as it would drift later in the program. I believe there is no sync reference occurring on capture that locks video to audio. Latency between the built in camera and audio makes no sense as it is not just a video conferencing tool as almost every application has video capture built in.
Macbook pro
Mac OS X (10.4.6)
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Posts:
3,759
From:
London, UK - usually..
Registered:
Nov 7, 2001
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 4, 2008 9:57 AM
in response to: outofrange
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..or Extract the audio in iMovie, and slide it along by the requisite number of frames ..easily done in iMovie HD 6.
G3, G4, G5, Intel Mac mini, late '08 MBP; iMovie 2,3,4,5,6,7; FCE HD, FCP HD;
Mac OS X (10.5.5)
Sony, Canon, Panny HD cams; FireWire drives, iPods, AppleTV, iPhone, etc.
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483
Registered:
Sep 2, 2004
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 4, 2008 12:06 PM
in response to: David Babsky
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Hi David,
I don't know if this is easily done in iMovie 08. anybody know?
you can export the audio - but then what? have double audio (giant file) after import? or?
Macbook Pro 2.4
Mac OS X (10.5.5)
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Posts:
6,726
From:
Charlotte, NC
Registered:
Jul 8, 2007
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 4, 2008 12:32 PM
in response to: Rev Dave
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IN Imovie 08, Select the clip you want. (Yellow Rubber Band should be around it). Now use Command-Shaft-Drag (with left mouse button) to drag the audio portion from the clip. Drag the audio onto the first thumbnail of the clip and drop it there. You should see a green video track under the clip, which you can move forward and backward. You will then need to go into the original video clip, go into the sound settings, and turn the volume to zero (so that only the audio clip is audible.)
iMac 24 2.8Ghz, iPhone, ATV
Mac OS X (10.5.5)
Parallels 5584 with XP, Panasonic HDC-SD5
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Posts:
647
Registered:
Nov 4, 2004
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 4, 2008 3:21 PM
in response to: outofrange
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its seems to me that the purpose for the camera is for both video chatting and realtime video recording. i'm having the same latency problem with camera. very annoying. they need to fix latency or have some type of buffer range you can change like they do in logic. and the less workarounds you have in life, the more time you have to be creative.
i agree with rev
G5 Dual 2.0
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Posts:
2
From:
Fort Worth, TX
Registered:
Dec 6, 2008
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 6, 2008 9:14 AM
in response to: Rev Dave
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Definitely a serious latency issue for me as well. Video is 5-6 frames behind the audio; certainly unacceptable for movies. If you are making a movie in iMovie with your built-in camera, there is really no reason for the software to not automatically offset the audio to match the video as you are recording.
Definitely something Apple should fix in the next update of iMovie.
Cheers to Rev Dave for pointing this out.
MacBook Pro 2.4GHz
Mac OS X (10.5.2)
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483
Registered:
Sep 2, 2004
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 13, 2008 8:59 AM
in response to: Fort Worth Brian
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Hi folks,
Well, now that I see that others are having the same problem - now I have to ask:
Q: Is this a software or hardware problem? Is there a hardware issue with the iSight camera - or a software bug?
BTW: I have to point out that I haven't tried tests with a real firewire/USB camera yet...
Macbook Pro 2.4
Mac OS X (10.5.5)
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483
Registered:
Sep 2, 2004
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 15, 2008 4:38 PM
in response to: Rev Dave
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Still curious ...
Q: Is this a software or hardware problem? Is there a hardware issue with the 2008 iSight built-in camera - or a software bug?
Macbook Pro 2.4
Mac OS X (10.5.5)
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Posts:
2
From:
Fort Worth, TX
Registered:
Dec 6, 2008
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 29, 2008 11:47 AM
in response to: Rev Dave
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I'm going to have to say it is probably a hardware problem, in that the hardware can't process the video fast enough to keep up with the audio. That being said, the software could easily fix this by having a "lock audio/video" checkbox that would keep them in sync by delaying the audio to match the video. Which would be great in iMovie, but not in iChat, so they are still probably having meetings about it....
MacBook Pro 2.4GHz
Mac OS X (10.5.2)
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483
Registered:
Sep 2, 2004
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Dec 30, 2008 8:48 AM
in response to: Fort Worth Brian
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"lock audio/video" - sounds like a great idea - but no need for a checkbox except in maybe iChat - cause you would always want it active in anything but maybe live chat - so it just should be built into the software directly - like iMovie etc.
Pass the doughnuts! Meeting almost over....
Macbook Pro 2.4
Mac OS X (10.5.5)
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Posts:
2
From:
Keene, NH, USA
Registered:
Jan 2, 2009
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Re: Video Latency Issue On The Mac Book Pro 2.4 With Leopard 10.5.5
Posted:
Jan 2, 2009 5:58 PM
in response to: Fort Worth Brian
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I am experiencing the same incredibly frustrating problem as well. When I record directly into iMovie
'08, the video lags the audio by a fraction of a second.
I have tried shutting down all other applications and having only iMovie up. Same problem.
I tried recording the video into QuickTime instead of iMovie and experienced the same problem. (Which makes me think it is perhaps a hardware or operating system issue.)
I tried the technique suggested here and on other sites of "double-dragging" the clip from the Events pane into a project (one normal drag and one Shift+Cmd drag) so that I had the audio and video as two separate tracks. After muting the audio on the video track, I then attempted to slide the audio over to sync it with the video, but even down at the 1/2 second zoom setting I didn't seem to have enough granularity to move the audio so that it was exactly in sync with the video. I was wishing I could use the arrow keys or something like that to move the audio just one frame at a time.
All I want to do is record a video directly into iMovie '08 - this would seem to be something trivial to do!
MacBook Pro
Mac OS X (10.5.6)
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