Problem with HDV 1080i60 footage in FCP

[Overlook]

Up to this point my only HD experience has been with P2 formats but today I'm editing some HDV 1080i60 footage for the first time. I'm using FCP.

This HDV footage seems to be pumping its resolution. By this I mean the resolution, or sharpness, goes up and down every 1/2 second or so. It pumps in and out of sharpness.

If I step thru the footage it still does so. Is this an issue with the footage or is FCP doing this due to bandwidth limitations? (I'm editing on a 1.25 GHz powerbook with 2 GB ram. I'm viewing on the screen of the laptop.)

I don't thing that this is the camera auto-focusing because it is happening too fast. I don't know what camera was used.

Thanks.

[Barry_Green]

Sounds like a problem in the HDV footage itself... You can get variable resolution between groups of frames depending on how severely the footage taxes the codec. 1080/60i HDV groups its footage together in 1/2-second increments, 15 frames at a time. So if you're seeing this "pumping" effect taking place at 15-frame increments, then that would be exactly what it is.

[Overlook]

WOW! I checked more carefully. What seems to be happening is that every 15 frames there is a clear frame or two and then it goes soft until 15 frames later. Is this typical of all HDV footage?!

The shot is a wideshot of a garden. Lots of fine detail of small leaves. Camera pans across. Yes, this would tax a codec, but I'm a shocked at how bad. Surly, there is something wrong. Could I have some settings wrong in FCP? I have set my sequence properly, I think, to match the footage.

[Overlook]

Is it possible that FCP, while editing, makes the problem seem worse than it is? I ask this because two seasoned producers, including the DP, have viewed the material and have not said there are any problems with the footage. Is it possible it looks OK on a CRT, or in the camera?

I know this sounds a little illogical but I'm grasping.

[ozduc]

WOW! I checked more carefully. What seems to be happening is that every 15 frames there is a clear frame or two and then it goes soft until 15 frames later. Is this typical of all HDV footage?!


Well that would make total sense. It's probably the GOP compression at work. Every 15 frames you have a complete frame, all others in between are basically made up from the 1st and 15th frame.

[Overlook]

How is it possible then to get decent footage with HDV? Surely people do. I haven't had any experience shooting HDV and this is my first editing it.

[Barry_Green]

WOW! I checked more carefully. What seems to be happening is that every 15 frames there is a clear frame or two and then it goes soft until 15 frames later. Is this typical of all HDV footage?!
It is the way HDV works. The question is whether there's enough bandwidth available to adequately render the detail in the shot.


The shot is a wideshot of a garden. Lots of fine detail of small leaves. Camera pans across. Yes, this would tax a codec, but I'm a shocked at how bad.
Sounds like a perfect storm for overloading HDV. There are reasons that some of us just won't use the format. It works perfectly well in some circumstances, and in other circumstances it just can't cope.

I'm sure it doesn't tax it nearly as badly as I've pushed it though. You wanna see some bad HDV footage, try putting smoke and fire and rippling water and strobelights all in the same shot, all while hand-held.

Now, the question is: how many times would you do something like that? If you're shooting interviews HDV can do very well. If you're shooting complex detailed scenes with lots of changes, it does quite poorly. Sounds like your scenario was somewhere inbetween.


Surly, there is something wrong. Could I have some settings wrong in FCP? I have set my sequence properly, I think, to match the footage.
Post the raw footage and let us see. What form is the raw footage in? Ideally it would be an MPEG-2 quicktime movie that was captured directly from the tape, and not some recompressed form of MPEG-2 or AIC.

[Barry_Green]

How is it possible then to get decent footage with HDV? Surely people do. I haven't had any experience shooting HDV and this is my first editing it.
You can get very decent footage with it as long as you don't overload it. If you overload it the results can range from mediocre to hideous. But if you don't tax it it can look very, very good.

[BenB]

You're footage I bet is fine. FCP on your Powerbook is trying to comprimise image quality for RT playback. This is normal. First, never edit HDV native, it's a roayl PITA, as you're finding out. Always capture and edit in FCP with the Apple Intermediate Codec. Will make editing much faster, smoother, easier, more consistant.

I did an article and got to interview the product managers of Avid, PPro, Edius, Vegas, etc. ALL in the end said that all ad hype aside, native HDV on any NLE takes a LOT of CPU horsepower, and all HIGHLY recommended using intermediate codecs for HDV editing.

And don't worry, you won't lose any image quality using AIC.

[Barry_Green]

He said he can see the degradation when he steps through frame-by-frame. FCP wouldn't be causing that, would it? It happens every 15th frame, and he's single-frame stepping through it. That's why I think it's got to be in the source footage.

[TimurCivan]

perhaps too the camera was focus hunting?

[Overlook]

I exported a small segment from a timeline and although it must have been too large for QT to play, the degredation seemed like it was gone. At least there wasn't a pumping effect every 15 frames. So BenB's comments make sense.

Is there a way to convert to AIC after capturing. Everything has already been captured, 8 hours worth. I don't have the tapes or an HDV deck/camera.

All is not lost because I can redigitise or convert later but can I convert the native capture?

[Overlook]

Ben, this article you mention, is it available anywhere?

[Overlook]

I did some tests. I exported a clip using the Apple Intermediate Codec. I imported it into my project and created a new sequence. I cut the AIC version of the clip into the sequence. I had to set the compressor of the sequence to AIC to avoid render.

Clip plays fine.

Still how to covert the 8 hours andseveral hundred clips?

My thought at the moment is to just edit as is. When I'm done I will create a sequence with AIC as the compressor and then render all the clips.

Does this make any sense?

If my output is going to be a nested 16:9 sequence in a 4:3 frame with letterbox which will be put to DVD, will the computer just process everything for me regardless of how bad it looks while editing?

Thanks.

[Overlook]

Ben, I think I found your article. It looks good. Will learn from it.

http://www.eventdv.net/Articles/PrintArticle.aspx?ArticleID=11892