Well, all we know for sure is that you have an mp4 file and you run after effects CS6. How about trying for information that gives people a fighting chance at diagnosis?
As Dave said, we know nothing about your project, your sources, your render settings or your system, so this is not going anywhere.
- What version of After Effects? AE 18.104.22.1688
- Have you installed the recent updates? I am on the trial version, it's about 10 days old.
- What operating system? Mac OSX 10.8.3
- What kind(s) of source footage? Mp4 exported from Handbrake, this file plays fine in QT and VLC
- What were you doing when the problem occurred? There's no error message, it's simply a spot in the mp4 file that AE decides to change the audio
- Has this ever worked before? Yes
- Do you have QuickTime installed. Yes
- What other software are you running? Photoshop, Mail, Chrome etc. Computer restart did not affect issue
- Do you have any third-party effects or codecs installed? No
- Tell us about your computer hardware.
Processor 2.7 GHz Intel Core i7
Memory 8 GB 1600 MHz DDR3
Graphics NVIDIA GeForce GT 650M 1024 MB
- Do you have any third-party I/O hardware? No
- Are you using OpenGL features in After Effects? I'm using whatever is right out of the box, so probably no.
- Does the problem only happen with your final output, RAM preview, or both? Both
- Are you using Render Multiple Frames Simultaneously multiprocessing? No
- What is the exact sequence of steps that you are taking? The video is placed on the stage, that's all I've done to it. Then at a certain point in the video, the audio cuts out for a second and then jumps back to the beginning, while the video continues to play correctly. I have tried importing a new video in case the old one was corrupted, and it has the same issue.
I saw your reply in my email, but not in this thread. You answered the diagnostic questions.
Based on the answers, I would re-export the clip from Handbrake, and I would NOT use mp4. Try another Quicktime codec. For AE work, I like the PNG codec. Don't forget to include the audio track.
I suspect that the codec you chose in that mp4 media container multiplexes its audio: the audio is embedded right in the video track. AE needs a separate audio track. You may have also selected a codec that uses interframe compression like h.264, which is not AE's favorite codec. If it turns out to be the wrong codec, consider yourself lucky that you got AE to read the audio AT ALL.
Thanks, there's no change though with updates installed (as well as a CUDA update).
I think the problem is the fact that the MOV was exported from Avid. I can't use the MOV directly because I am getting this error:
"[filename] cannot be inported – this 'MooV' file is damaged or unsupported"
If there is a way to fix that and skip conversion altogether that would be ideal. My Handbrake conversion options are limited to mp4 (with h.264, mpeg-2 and mpeg-4 codec) and mkv, which doesn't work in AE.
I got two MOV files from this client and converted them both to mp4 (h.264 codec) in Handbrake, only one is doing this.
Well, try to install the Avid CoDecs and use the originals. Other than that this behavior is typical of Avid files that haven't been flattened properly or are reference clips that contain links to OMF/ MXF files on another storage device. Without going back to the original edit on the Avid, you can't fix any of those errors. Not your fault then, your client simply exported them wrongly.
Where do you get those codecs and how do you install them? What are they called?
The Avid LE CoDecs are free, but require registering on their support page. I'm sure you can find them on other sites as well.
AE is really chugging now, but the good news is that the codec installation solved the issue. Thanks!