audio file clipped
by John Dean on Apr 27, 2011 at 6:01:49 pm
when I import an MPEG-4 audio file into the project window, then into my comp, the last few seconds of the file is clipped off. my comp duration is longer than the audio file so that's not it. any idea why this is happening or what the fix is? thanks.
Re: audio file clipped by Dave LaRonde on Apr 27, 2011 at 6:28:37 pm
Hmmm.... mpeg4 is a video codec. Since I made an mp4 file just minutes ago, I know the audio channel can be compressed. And mp4 is a long-gop codec. If you're NOT running AE 10 (aka CS5), you need to read the following:
Dave's Stock Answer #1:
If the footage you imported into AE is any kind of the following -- footage in an HDV acquisition codec, MPEG1, MPEG2, AVCHD, mp4, mts, m2t, H.261 or H.264 -- you need to convert it to a different codec.
These kinds of footage use temporal, or interframe compression. They have keyframes at regular intervals, containing complete frame information. However, the frames in between do NOT have complete information. Interframe codecs toss out duplicated information.
In order to maintain peak rendering efficiency, AE needs complete information for each and every frame. But because these kinds of footage contain only partial information, AE freaks out, resulting in a wide variety of problems.
I'm a Mac guy, so I like to convert to Quicktime movies in the Animation or PNG codecs; both are lossless. I'll use Apple's Compressor, Adobe Media Encoder or Quicktime Pro to do it.
And in any case, NO version of after effects likes compressed audio. So if you actually meant mp3, you should convert it to a wav or aiff file. And if this is just the audio channel of an mpeg4 file -- but it's comprssed -- you'd have to do the same thing.
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