sTutTerinG Video: Something to just accept?

I've been on two other forums with this artifact and they suggested I check with LAFCPUG for more depth.
This problem is shared by three different edit systems in three different studios, so I think it might be a common problem. Yet, maybe it's just these few systems...?

Here's the deal: I export a timeline of any format to self-contained .mov . If it's played on computer monitors it will stutter (movement across the screen will stop and start, rapidly, irregularly), a little or a lot, but if played via a TV monitor it is stable. I sent out samples to 20 regular people, people like our clients, and almost all experience this.

- ProRes / DV / 8-bit Compressed / etc - They all stutter
- Compressed to H264 / interlaced or progressive - they all stutter.
- It's random, with stutters at different points each time it's played.
- Sometimes none, sometimes a lot... with the same clip.

Is this something to accept, a random stutter here and there in any show, if it's played via computer? I hope not!! What about projecting from computers? What about playing HD versions of shows to clients?

Is there a compression or transcode that will smooth out this stutter problem? Remember, it's not a compression issue, as it occurs with a straightforward export with the same format.


If you're interested in checking this... HERE'S A SIMPLE TEST
Here is a link to a very small and simple test project (235kb) ---- [rcpt.yousendit.com] ---- with very basic movement created within FCP with generated mattes, as simple shapes moving across the screen. No external source video. A cross... a box... a simple wipe, moving across the screen within 4 seconds One timeline in ProRes, one in DV, one in 8-bit uncompressed.
Are you able to export any of these so that computer viewing is stable?

Any experience out there with this? There must be...




Thanks MUCH,
Ralph

I don't know if QT player is a frame accurate playback device. That said, I ran your experiment with a couple of clips. I used the Pro Res interlaced and progressive sequences and both played back fine with no stuttering.

Stuttering playback can sometimes be a result of the drive playing the clip back. What systems are you attempting this on? How fast/full are the drives that you're storing the media?

I've never had a problem watching full frame HD encoded to H264. It's typically a low bandwidth codec.

Now Uncompressed can give you stutters if you're not using a RAID because it's got a pretty high bandwidth.

Andy

If even a DV movie file stutters, you've got something wrong with your setup. All of your setups. Yeah, first suspect is the drives. If you try to use USB drives to playback these files, or if you tried to play them back from a data disc (CD/DVD), they'd never play back well.


www.derekmok.com

Stuttering is NOT normal. If it happens to me, it is rare, and I know something is wrong. What causes it? Slow hard drives that you are using as Media drives. The codecs you are trying to play back. Amount of RAM (odd numbers like 5GB cause issues)

QT player almost never plays back higher end codecs at full frame rates.


www.shanerosseditor.com

Listen to THE EDIT BAY Podcast on iTunes
[itunes.apple.com]

PB/sequence settings and drives are the first things to look at.

One other thing to be aware of is that your Motion tab-Y key frame coordinates(right window) could also be contributing to the problem.

You should get smoother motion when your Y key frame values are even whole numbers. Odd numbers like 5.08, 1.47, and 694.45(found in the ProRes Progressive seq.) are contributing to the PB problem. Change 5.08 to 6, 1.47 to 2, etc. The change in where the item moves based on the new values shouldn't be big enough to notice.

It's gratifying to get the feedback from the group. (I've been on location for a week and am now slamming to get an edit I left behind done and out.)

Most of the comments have to do with the playback systems people use, something we have no control over, yet we must try to "coddle" them, as we want as many people as possible to have a prime viewing experience.

I would love it if it were my settings or one of my drives causing this and that I was PRODUCING something that has stutters built into it. That's fixable...

The stuttering occurs with DV and H.264 files that should be able to play well on almost any modern computer.

**I wonder if there's a compression format that is known for being very stable...?

I'm not sure how to test for this, among this group that typically has high end equipment (unlike average viewers). Over the next days, in between jump-cuts and renders, I'll try to think of a way to test for it.

Thanks again,
R

I guess this is a sticky problem.

If it's a playback issue, then I/we have no control over it.

If I'm producing the stuttering (as are a number of other editors in San Diego) then I'd like to get on it and correct whatever setting or ? is involved.
(I'm working with Mac Pro, dual core; 4Mb RAM, a TB drive less than 50% full (7200rpm, 32mb cache))

It would be great to know if there's a format that will not stutter when played by Quickitime. Any ideas out there?

Thanks for whatever can be recommended. This may well be a problem that affects us all and it would be great to know ow to overcome it.

Thanks!
-Ralph

You're looking for a magic bullet and there isn't one. If you ask me for a QT format that won't stutter, I'm going to tell you H.264. I have never had a single stutter from any H264 movie I have ever played. But then again, the codec is not the only reason that a video might stutter.

H264 is a low-bandwidth codec perfect for web viewing and client review and all sorts of things. If you are stuttering an H264 quicktime, then it's time to stop looking at the codec and start looking at everything else that could cause your problem.

You say that you would love it if the drives were causing the problem because that's fixable, but you haven't sufficiently ruled your drives out as an issue. At least not in these posts. Just because your drives outwardly look ok and they aren't full doesn't mean they aren't the cause of your issues. Have you replaced your media drive with a known good drive and gotten the same issue? Have you checked the fragmentation of your system drive? Have you repaired permissions? Have you checked your RAM for bad RAM? Have you checked for conflicting applications or exotic QT decoders?

You can't keep asking us to provide you with some magical setting or codec that will make your troubles go away. We're not hiding anything from you. H264 is a format that won't stutter unless there's something else wrong with the computer.

Andy

For all the postings you're writing, I'm still not seeing one crucial piece of information:

What interface are you using for the drives?

If even your eSATA or FireWire 800 drives are playing back DV movies choppily, 720x480 at 29.97fps, then you really have problems.

But if you're trying to use a USB hookup...then duh.

Before you accuse the formats -- and 95 per cent of computers I've met can play DV back smoothly, even anemic laptops owned by actor friends -- you need to look at your own hardware.


www.derekmok.com

Two very good replies, Andy and Derek. Yes, I haven't supplied enough information as yet and I haven't gone through all the inspections and checks that Andy pointed out. I'll next do a clean install of OS and FCP onto a new drive, to see what that will create.

Yet there are some revealing "knowns".

- I sent the test clips to 12 regular people, to try on their systems. 9 of 12 experienced stuttering playback on at least one of the three test clipst. As Derek says, 95% should have played back at least the DV clip cleanly.

- Current drive in use is internal 1TB, 7200rpm, 32mb cache, Western Digital Black, new. I've tried three other drives, one external FW 400, one eSATA, and another internal drive, all with 80% or less of full capacity. All have the same results.

- I've executed the same test on three separate FCP platforms, two MacPro's (with FCP7) and one Mac Book (FCP6), at different studios, with the same results. This led me to think that it might not be just my edit system.

- To limit variables, no external media is in use. All video is created via FCP's internal generators. (a colored matte is manipulated)


I'll try out the clean install,etc. on a new drive; and also try to get some more editors to execute the simple test and send results back to me.

I'll report back with results.

Would you be willing to try the test? The simple project can be downloaded here:
[rcpt.yousendit.com]

Here is a link to a very small and simple test project (235kb)... with very basic movement created within FCP with generated mattes, as simple shapes moving across the screen. No external source video. A cross... a box... a simple wipe, moving across the screen within 4 seconds. One timeline in ProRes, one in DV.

If you can try this, please export the wipe clip in the ProRes timeline and the wipe clip in DV timeline... both as a simple self-contained movie and upload to me via YouSendIt.com
User: rwc@cox.net
Pass: summerpops
The interface is pretty clear, just put rwc@cox.net in the To: email field

Thanks a lot,
Ralph