Awful HDV playback on FCP6 problem

[Geoffrey Cox]

Hi All,

I have a problem playing HDV footage (shot with XH-A1) back in FCP 6.0.5 on my MacBook Pro 2.6 GHz Core Duo 2 (4 GB 667 MHz DDR2 SDRAM) running OS 10.5.7 especially footage shot with fast shutter speeds. This is the first time I've tried to edit HDV footage as previously I've always converted it to SD for other reasons, so I'm new to this.

When viewed direct from tape into a TV it looks fine but once imported into FCP it looks awful - stuttering, ghosting, jerky etc. though occasionally when I play it (in the viewer) it plays fine! Footage shot at slower shutter speeds (generally with a Z1) is better though still not right. Sometimes even playback gets stuck and flips back and forth between a few frames and reports a general error, even with the slower shutter footage suggesting there might be more than one problem here.

It makes no difference whether the clips are on the computer's hard drive or an external one. I should say that when I select the medium quality playback option the problem stops (though obviously it looks poor) suggesting to me it is a lack of processing power problem but I thought one could edit HDV OK on a MacBook?

Tried playing the clips iMovie and the problem is the same and QT (7.6.2) which is slightly better but still awful.

I'd be grateful for any suggestions as at present I can't see how I can continue the project.

Thanks.

[Reuben Miller]

Originally Posted by Geoffrey Cox

Hi All,

I have a problem playing HDV footage (shot with XH-A1) back in FCP 6.0.5 on my MacBook Pro 2.6 GHz Core Duo 2 (4 GB 667 MHz DDR2 SDRAM) running OS 10.5.7 especially footage shot with fast shutter speeds. This is the first time I've tried to edit HDV footage as previously I've always converted it to SD for other reasons, so I'm new to this.

When viewed direct from tape into a TV it looks fine but once imported into FCP it looks awful - stuttering, ghosting, jerky etc. though occasionally when I play it (in the viewer) it plays fine! Footage shot at slower shutter speeds (generally with a Z1) is better though still not right. Sometimes even playback gets stuck and flips back and forth between a few frames and reports a general error, even with the slower shutter footage suggesting there might be more than one problem here.

It makes no difference whether the clips are on the computer's hard drive or an external one. I should say that when I select the medium quality playback option the problem stops (though obviously it looks poor) suggesting to me it is a lack of processing power problem but I thought one could edit HDV OK on a MacBook?

Tried playing the clips iMovie and the problem is the same and QT (7.6.2) which is slightly better but still awful.

I'd be grateful for any suggestions as at present I can't see how I can continue the project.

Thanks.

I suspect your problem is that your harddrive is having a difficult time playing the footage back and running the OS and app at the same time.

Rule #1 for editing on ANY computer: Always store your media on a different drive than your OS/Application Drive.

You did not see many problems from the SD due to throughput. I would suggest a fast external HD such as a G-Raid, and see how that works for you.

Good Luck :)

[Greg Boston]

Originally Posted by Reuben Miller

You did not see many problems from the SD due to throughput.

Throughput is the same for HDV as it is SD. Both are 25mbs data rates. The HDV though, being more compressed as an MPEG2 product, taxes the CPU harder to decode the frames once they come through the hard drive pipe.

-gb-

[William Hohauser]

External drive should be FireWire, USB will cause problems like these.

Make sure you don't have any other programs open and running like PhotoShop.

If you have TechTool or another diagnostic program run it to make sure the hardware is OK, especially the memory. The fact that it plays fine at a lower resolution suggests that something is taxing your computer's resources.

I have an old 2gb MacBook Pro and it will occasionally choke on HDV (a frame stutter) but not ProRes.

[Boyd Ostroff]

I would also check your clip/sequence settings and be sure they are correct for whatever mode you shot in. Something is wrong somewhere... I am able to edit HDV fine on a system just like yours but dual 2.4ghz cpu. I am using a firewire 800 external hard drive.

[Geoffrey Cox]

Boyd, William, Greg, Reuben, thanks all for your suggestions. For reasons I don't understand the serious problem has stopped (in part) though I'd changed nothing at this point, simply booted my system up, loaded the project and pressed play!

However the motion is still not right - blurred with any close-up cross or angled movement (not present on the tape) - could this be that my computer cannot cope and that when I record back to tape it will be OK - I should try this.

Btw I'm using an external drive linked via Firewire 800 and the drive is 7200 rpm with hard disk average seek time 10 ms. Could it be that the fast shutter speeds I used cannot be accessed quickly enough? I tried capturing to Prores 422 but it made no difference. Can see the interlacing but this is not the blurring that I'm seeing which is a kind of motion blurring - also turned motion blur off in playback settings and tried numerous tweeks in a/v settings etc but to no avail - only playing back at medium quality stops the problem.

[Pete Cofrancesco]

Capture it as ProRes instead of HDV.

[Geoffrey Cox]

Originally Posted by Pete Cofrancesco

Capture it as ProRes instead of HDV.

Pete, tried this and it makes no difference at all.

[Pete Cofrancesco]

you could wipe the computer clean reinstall everything. drastic but i don't know what it could be.

[Boyd Ostroff]

Originally Posted by Geoffrey Cox

Could it be that the fast shutter speeds I used cannot be accessed quickly enough?

Shutter speed should have nothing to do with playback whatsoever. If you used some strange shutter speed it might make the footage look bad, but it would also look bad when playing back from tape on your TV.

Don't confuse shutter speed with frame rate. The Z1 is an interlaced camera and always operates at 30 frames per second (60 interlaced fields). The shutter speed controls how long the shutter is open during those 1/30 second time slices.

[Geoffrey Cox]

Thanks Boyd, yes I think I thought that anyway but wasn't wholly sure - the footage does have that fast shutter look about it (and not always so successfully so due to my inexperience) but this issue makes it look far worse and unusable. I'm beginning to wonder if it's not my LCD screen exacerbating things though it still looks far worse coming out of FCP than straight from tape.

[Boyd Ostroff]

How are you viewing the footage in FCP? Are you using an external computer monitor via the DVI port and Digital Cinema Desktop full screen mode? What is the resolution of the external monitor?

[Geoffrey Cox]

Originally Posted by Boyd Ostroff

How are you viewing the footage in FCP? Are you using an external computer monitor via the DVI port and Digital Cinema Desktop full screen mode? What is the resolution of the external monitor?

Hi Boyd - yes I'm using an external LCD monitor (Samsung T240 HD), resolution 1920x1200 with '1080p full HD supported'. It displays the image (via Digital Cinema Desktop full screen mode) in the correct 16:9 ratio with thin black bars top and bottom. I'm using the DVI port from the computer - the screen as a direct DVI in; I'v tried that as well as using an HDMI adapter but this makes no difference.