how to repair jerky clip stutters

meegwell · Post by **meegwell** » Wed Oct 22, 2008 10:10 pm

I've read a lot about the source of jerky output but not tips to fix my situation, which is:

DV capture via firewire is fine, no stutters in source files. (VS 11+).

When I add clips and effects, stutters pop up and remain, in the same spots, through preview and rendered DV (avi) file.

PC specs are posted in profile but generally its a intel 1.6 w/ 2GB, 7200 100gb free.

I haven't tried turning off the mcafee and such but I'll get to that. My real question is, since the source file is fine, do I need to re-do from scratch each clip that has a stutter in it or is there some way for them to be "rebuilt" by VS?

The stutters are often in pan & zoom still photos but in video clips as well.

Properties of Project:

NTSC drop frame (29.97 fps)
MPEG files
24 bits, 720 x 480, 29.97 fps
Lower Field First
(DVD-NTSC), 16:9
Video data rate: Variable (Max. 8000 kbps)
LPCM Audio, 48000 Hz, Stereo

Thanks,

Mike

Post by **Ron P.** » Wed Oct 22, 2008 10:18 pm

When creating your DV file, have you checked to make sure the field order is the same as that of your project settings? It may have been inadvertently set to Upper Field First.

Disabling your antivirus, instant messenger, and other non-essential services or programs is a good idea. That way you need not worry about one suddenly springing to life, interrupting things..

Post by **Ken Berry** » Wed Oct 22, 2008 10:24 pm

What you are trying to do, and the formats and properties you are using, are absolutely rock standard, and there is no obvious software-related reason why you should be getting stuttering. The only logical conclusion I can draw is that it is hardware-related. Your processor (1.6 GHz) is a bit on the light side, though I used regularly to convert DV to DVD-compliant mpeg-2 on an old 1 GHz computer, and users before that used even weaker processors with no problem.

However, VS11 is rather more demanding of computer resources than the earlier versions I was using on that older computer, and I used to disconnect from the internet, shut down my anti-virus and turn off as many background operations as possible. Any of these suddenly deciding to do something, or scan something else, would cause blips in the processing of the video.

So I can only agree with Vidoman that you should first turn off as many things as possible, and if necessary even develop a special video-only profile which you can log-on to when using VS.

DVDDoug · Post by **DVDDoug** » Wed Oct 22, 2008 11:20 pm

I have no idea what the problem is....

But your processor speed or programs running in the background should not cause glitches in the rendered file!

The editing/processing/rendering is all "number crunching" by the CPU. There are things that can slow-down the process, but nothing like that should generate errors or corrupt the data.

Of course, speed and interruptions can affect real-time operations, such as capture, playback and preview.

Post by **Ken Berry** » Wed Oct 22, 2008 11:26 pm

On the old computer I mentioned above, which was in my pre-broadband days, if I received a phone call (same line as my dial-up modem but with a call-waiting facility), then my DV > mpeg-2 conversions most definitely suffered dropped frames at that point. Ditto if the anti-virus decided to scan something while the conversion was going on... So I am not absolutely certainly we can rule out hardware resources as being a cause in the current situation...

meegwell · Post by **meegwell** » Mon Oct 27, 2008 8:45 pm

thanks all...I will first try a "lite" setup closing down all things unecessary and run a few tests. My pc has been running a bit slow lately and could use a tune up.

What about the repair? Do I need to re-do each clip from scratch or is there a was to let it re-calc given all the criteria it already has?

2Dogs · Post by **2Dogs** » Mon Oct 27, 2008 11:23 pm

From the hard drive info in your "system" info, I would have guessed that you had a desktop pc - but from the processor, do you actually have a laptop? If so, and if it's a dual core machine, you won't see any appreciable speed benefit from turning off unnecessary programs, services and processes - although it may still be a good idea to do so to minimise the risk of conflicts.

It might be worth you running chkdsk - from the hard drive properties, select "tools" > "error checking" and click on "check now". The test will require you to re-boot.

Then run disc cleanup and then run the defragmenter.

All of that may take a bit of time but will rule out some possible causes of your problems.

babdi · Post by **babdi** » Tue Oct 28, 2008 5:13 am

I am not sure if increasing windows SWAP size will help

2Dogs · Post by **2Dogs** » Tue Oct 28, 2008 1:37 pm

babdi wrote:I am not sure if increasing windows SWAP size will help

Interesting point, Babdi.

I always set my swap file to be a fixed size - otherwise Windows might decide to resize it, causing a delay in proceedings when it does so, but not necessarily any visible defects in rendered video. The general rule used to be to set the swap file to 2 x RAM, which in your case would be 4Gb - but to me that is excessive, and I might use 2Gb for both the swap file minimum and maximum sizes. It may not help, but it won't do any harm.

meegwell · Post by **meegwell** » Wed Nov 05, 2008 9:39 pm

thanks again for great input. I have several of these clips so I was mainly wondering about about the repair? Do I need to re-do each clip from scratch or is there a was to let it re-calc given all the criteria it already has?

meegwell · Post by **meegwell** » Mon Dec 01, 2008 4:14 pm

just bumping this question:

thanks again for great input. I have several of these clips so I was mainly wondering about about the repair? Do I need to re-do each clip from scratch or is there a was to let it re-calc given all the criteria it already has?

Black Lab · Post by **Black Lab** » Mon Dec 01, 2008 6:11 pm

Not sure what you mean by "re-do each clip from scratch". If the captured clips are fine there is no need to re-capture. Have you tried re-rendering with excess apps turned off?

meegwell · Post by **meegwell** » Mon Dec 15, 2008 7:45 pm

ahh, I think that is what I am trying to do. Re-render. I assume that is straight forward? Yes, the source clips are fine. Is there a process for re-rendering? Please excuse my ignorance.

Black Lab · Post by **Black Lab** » Mon Dec 15, 2008 8:58 pm

Clip>Save Trimmed Video will render an edited clip to a new clip. Share>Create Video File will render your entire project to a new clip.