-
audio out of sync (not in the usual way)
Hi
When I export my 4 minute project as any file type (I have been specified a few by various tv stations) and play it on another computer the audio is a little out of sync with the video.
It doesn’t slip out of sync, it just is out of sync, by probably (at a guess) a couple of fames.
I thought that it might be that my laptop was not fast enough to process the big file so I converted the output file into a small file, internet friendly etc. But the audio is still out of time.
For instance when an original file was a H264 1920×1280 max quality file, 48k stereo audio. So I converted it to an h264 640×480 1,550 bitrate file. AAC audio. The audio was still out of sync.
I wonder if it is because the machine I was doing the editing on had a firewire (Apogee Duet) interface, perhaps it wasn’t set up to compensate for the audio buffer latency? Therefore what seemed on time on that machine was actually out on other machines. Do you think this could be possible?
Any help would be appreciated. Note that I am not sitting in front of the editing machine at the moment.
Thanks in advance
Matt
-
5 Replies
-
first and foremost, H264 should not be used in FCP, it has to be converted first to an editing codec before being brought into FCP.
Having you been syncing the audio with the video manually or just using clips with video and audio together.
How are you monitoring video and audio in FCP? External monitor and video card?
-
Thanks for your reply
Firstly, I know, I wasn’t editing in h264, I was outputting in H264, as per MTV’s specific request.
It was this output file that had the audio out of sync on another computer (my macbook pro) (it plays fine on the editing computer, a macpro). So I used quicktime to convert this H264 file to a smaller file purely to see if the audio was out of sync when the computer wasn’t under such a strain. This smaller file was still out of sync on my laptop.
To answer your other questions:
I have been syncing audio manually, not using clips with audio (its a music video).
On the editing computer, I am only monitoring video on the computer monitor, and the audio through an apogee firewire “duet”
cheers
Matt -
[matt thomas] “On the editing computer, I am only monitoring video on the computer monitor, and the audio through an apogee firewire “duet””
My guess is this is where the problem is, you have a delay between the audio and video, so your syncing is off.
To test, pull in a video clip with audio and look for the sync issue. IF it looks out of sync that is your problem.
-
thanks
that was my thought too, I will go back to the editing place ( a friends house) and try this.
Its extra hard as his copy of FCP is in german (he’s swiss), and I only speak basic german, so its hard for me to look through settings, oh well 🙂
thanks again for your time
matt
-
OK, strange thing
I made a DVD in iDVD out of the h264 file.
When I play the DVD on my laptop the audio and video are out of sync. (onboard sound/speakers, laptop screen, macbook pro intel 2.4GHZ, Core 2, 4GB RAM)
But then I play it on my DVD player and TV and it is fine.
Weird..
Anyway, I think I can assume that its ok, and deliver it to MTV..
Matt
Reply to this Discussion! Login or Sign Up