[Julie Turner]

Hi All,

I wanted to follow up on my own post in case anyone finds this via search.

In my case, I narrowed down the problem clips and tried to find what was in common amongst them. In the end, the only thing in common was that they all used the aac high efficiency codec (AAC-HE) or version 2 of the HE codec. I don’t know why this would cause a problem—or even for sure whether it was the thing causing the problem—but that was most in common amongst them.

I also found that a bunch of the problem clips had 44.1khz sample rates while my project was 48khz. But this wasn’t true of all clips and I had the same glitchy problems from clips that were sampled at 48khz.

I *did* realize once I narrowed down the problem that there were some clues in the audio waveform representation on the timeline … a sort of drop-out was visible, even though it usually caused no audible issue. This wasn’t true universally, but it was much of the time.

So anyway, in the end my strategy for repair became an iterative process something along these lines:
– re-encode the original clip’s audio to aac (not high efficiency) using ffmpeg
– if that didn’t work, upsample any 44.1khz audio to 48khz.
– relink

One of those worked for about half my problem clips. From there, I had to:
– sometimes open the clip in QT and export back out (fixed a missing audio issue in FCPx)
– sometimes open the clip in VLC and do the same (if QT trick didn’t work)
– re-encode both audio and video

Occasionally no matter what I did the new version was a tiny bit shorter than the old and FCPx wouldn’t relink it. Also, sometimes, especially when sample rate changed from 44.1 to 48 I had to mod the segment because the audio shifted position by around 1 frame.

Finally, when all else failed (and it did a few times), I ended up re-encoded the source video to webm/opus and then back to h264/aac. Somehow this seemed to “cleanse” the file, removing whatever had been buried in it that gave FCPx fits. I’m sure I lost quality here, but this was better than the glitchy clicks I got on export.

HTH someone else some day.

[Julie Turner]

Just to give a sense of what I’m seeing/hearing, here’s a screenshot from Audition:

Neither the original media—nor the playback/timeline in final cut—has this dropout. And these are everywhere…

[Julie Turner]

Well, I exported AIFF audio to Audition so I could take a look and it’s a horror show. There are drop-outs everywhere. These aren’t audible or evident in FCPx, but are present in the output. Like every few seconds. It’s like the signal just disappears, and it happens in the worst ways (e.g. going from signal to 0 in 1 sample).

Any ideas are really appreciated … not sure how these months of work isn’t trash right now….

[Julie Turner]

Hi everybody,

Well, I got somewhere with a keyframed mask of his face, thanks so much. It’s so far from great, but at least it’s now not abysmal! Here’s before and after:

I’ll tweak it more if I get a chance (clearly there’s a lot that still needs work with the feather area)…

[Julie Turner]

Oh, sorry, that was Jeff that said that about the face being low contrast … (wish there was an edit button here).

[Julie Turner]

To clarify, the clip I linked to is before I’ve tried any correction. Presumably that’s how it was created by CNN? Thanks for the tips; will try both of your suggestions and see what I come up with. As Oliver mentioned, the face is so washed out it just looks strange and unreal.

[Julie Turner]

Well, I spoke too soon. It swapped in the right version, but my edits aren’t aligning perfectly. It’s as if all my edits are shifted about 15 frames or so. Still a huge improvement over redoing this segment, but wanted to mention it for others.

[Julie Turner]

Relinking to the higher res version worked perfectly! Just what I was hoping for, in that it preserved absolutely every bit of previous work. The test I just ran was on an ideal test case: I had a higher-res file whose specs identically matched the lower-res I’d been working from (frame rate, precise duration, etc.). However, with the last test I ran it wasn’t so perfect (same frame rate but not identical duration) … so not sure it would have worked for that one. Thanks everybody, you’ve saved me a ton of work!

[Julie Turner]

Just tried it myself. It all appears to go fine, and the clip (container)—when opened in the timeline—now shows the highres clip. But favorites from that clip as contained in my clip container as part of the main project didn’t change to the high res file. However, it appears that if I copy the favorites back into the main project (from the clip I used your overwrite technique on) that those are the high res version. So in other words, this operation didn’t update the clip container but it does give me close to that.

I’m not many of my others will have exact swapouts (same frame rate, etc…) but will see. Thanks!

[Julie Turner]

Interesting! The first clip I looked at for this is at least the same frame rate and duration. So I went through your steps and at when I try to overwrite FCPx throws up a warning dialog that says “Are You Sure You Want to Edit the Contents of this Clip?” Will take a break before deciding if I’ll try it ☺ Would be curious to know if anyone else has tried this before?