24f mode and iMovie
 

Hello. I use iMovie to import footage from my HV40. I bought the HV40 for it's 24f mode which looks great on my camera.

When I capture/import the footage, the audio goes out of sync from the footage. On the camera it looks normal, but when importing, it's totally off.

I am not extremely well-versed in tech-speak, so if anyone has any ideas on how to correct this, please help!

Eeek.

I know exactly what's happening.

On the earlier, HV20 and HV30 models, the 24p stream was recorded as "hidden" within a 60i format.

There's some more information here: Eugenia's Rants and Thoughts Blog Archive Canon HV20 24p Pulldown

With this "hidden" format, you'd get some artifacts because the video was, essentially, "scrambled" and you needed to first capture the footage and then "unscramble" it, using a process called "inverse telecine."

However, that "scrambled" footage still looked good and the audio and video remained in sync.

But on the HV40, it records to 24p "natively" - which means that the information isn't "scrambled."

This can be a problem because iMovie - and even Final Cut Express - will only capture 60i streams.

So what iMovie is doing is trying to capture the 24p footage as 60i streams. Which means it's trying to throw 30 frames per second into a timeline meant to have only 24 frames per second.

Thus the audio sync issue.

The only solution would be to find some way to capture the footage directly as 24p - as far as I can tell, only Final Cut Pro can do that at this time on a Mac.

Sorry.

Yes, I had the same problem. I wrote about it in the XH-a1 section. I don't know how to fix it in I movie, but in FCP you have to change the timeline settings for 24p. That being said, last night I did a shoot in 24p on my XH-A1, and mixed the footage in with what I shot on my HV30 and it was severely out of sink. I'm at the point where I won't shoot in 24p anymore. I think this is a Canon problem.

It's not a Canon problem, you're mixing two different things. If you shoot 24F with an XH A1, you edit in a 24.98 timeline and everything is perfect. But if you try to put footage from an HV30 which does 24p with the pulldown technique, then it's not going to drop into a 23.98 timeline properly without going through the pulldown removal process. You can buy software from Nattress Effects for about $100 to deal with that.

The HV40, on the other hand, is supposed to do "real" 24p and it should intercut fine within the same timeline as the XH A1's 24F footage. Should.

The previous post about iMovie and Final Cut Express is correct--they do not do 24p, so if you're editing in iMovie or FCE, you should shoot 60i.

Yes, I got a little frustrated with this problem and blamed on the first camera I could find, which happens to be my two Canons. I just got off the phone ( an hour ago) with Canon concerning this problem. Canon said it just like you stated it. However, they said the newer version of Final cut Pro ( which I have ) should convert any frame rate to fit in the timeline, and this obviously didn't happen. They didn't know why it didn't work. Neither do I.

I do recall a conversation with Apple once and stated I had an XH-A1, and was having some problems, and they told me they knew of some problems with the XH-A1. However to my glorious XH-A1's credit, the problems I had were of my own making. None the less I recall the guys at Apple help FCP said their were some issues around the A1.

The only reason I shoot in 24fp is to upload to YouTube. I have some custom settings in compressor which I apply to all of my Youtubes. I've noticed a vast improvement in the quality of the videos when I switched from 60fp to 24pf. Mike at Canon went on to say that 30pf is better than 24 pf for uploading to YouTube. I was always under the impression that 24pf was the best choice for the web. Mike said that Youtube converts down to 15 fps, and 30 divided by 2 is 15 and this works better than 24pf.

Not exactly.

I thought the same thing as well when I just dumped an hours worth of A1s HD 24F material into imovie HD. Picture was fine with no problem of taking the 24F at all. But the sound was off, just like everybody else's.

Then I went to my wife's newer (actually 2 years old) imac with iLife that has the newer imovie with the weird interface (and no ability to rubber band sound and no out to tape capacity).

I put in about ten minutes of the A1s 24F HD material and it was perfectly in sync. So I thought maybe my mac mini was just not fast enough. But you CAN get 24F HD into the new imovie with no problems.

I then down converted the HD material out of the A1s to Standard Def into the mac mini and the old imovie HD and the sound was in sync.

So, if you want to use HD 24F in imovie, it has to be the newer version, or if you want to use the older version of imovie HD, you can, but you have to go down to SD as you ingest into imovie.

At least this is what worked for me.

Kelly,

When you capture 24F video with the new iMovie, are the captured clips 24 frames per second or 30 frames per second (24 progressive frames + 6 interlaced frames)? In other words, does the camcorder export native 24 frames via firewire or does it apply pulldown and export as interlaced 30 frames?

P.

Well, there are 30 frames when it is ingested into imovie, but I'm not certain that any of the extra 6 are interlaced, but you may know better about this than I. All I know is that it is in sync and looks pretty good.