AVCHD Playback Stutter Problem after Importing

V

Vince27

Member
Hello everyone, I'm new to the site...

I wasn't sure where to post this, but since I just imported my footage through FCPX last night, & have a feeling this is an import problem, I figured this would be the best place to post...

I have an HMC150 which seems to shoot real nice (now that I have an idea of what I'm doing with it) and originally, I bought this camera because I wanted to go tapeless, and the price of the SDHC cards was right (as opposed to the p2 card system)...

I'm now thinking that maybe I made a mistake going with this technology because it seems AVCHD is one problem after another when it comes to importing & editing, which brings me to FCPX...

I just bought a pretty loaded 27" iMac with the idea of making my film with the new FCPX because from everything I read beforehand, FCPX is supposed to be the best current editing system for AVCHD - so I got the most powerful system I could afford - (8g RAM, 2g Dedicated for Video, i7 3.4) along w/ a 2T External G-Drive) - which is way more than what is recommended to run this program...

So i downloaded the free 30 day trial of FCPX & imported some footage last night to start getting my feet wet, and to my nightmare, I noticed that alot of the footage has certain spots where when you're watching it, it will slightly "stutter" or be "jerky" and from what I am aware of, It does't stutter like this when I view it on playback in the camera... so I'm thinking either I imported it wrong, or FCPX has a problem with AVCHD (as it seems so many other platforms do as well) - it's not "major" stuttering, but it's also Not Acceptable -

Aside from making my film I am also trying to pick up freelance work, but don't see how I can do either if my footage is going to have a stutter problem like this after I import it? - is the footage getting damaged through the import process??

I've yet to export the footage to a DVD, or export to youtube or something like that to see if it will still stutter after creating a project & exporting, so I'm not sure if this is a big deal or not...

when I imported...
i checked "create optimized media" & "separate mono" & "remove silent tracks" - thats it... no video analysis
from the tutorials I've watched, this seemed to be the right thing to do when importing...

the clips (about an hour's worth) seemed to import pretty fast (but then the background tasks went on for 3 hours!) -
another issue -> is that normal? or maybe is it better NOT to check anything when you import AVCHD into FCPX? -

The footage I imported was 720/60p -

I don't want to jump the gun here (because I know there are so many people now using DSLRs for almost everything out there (I believe the DSLR is the same AVCHD technology, as I know those cameras record to SDHC as well) - and I know there are alot of people who own the HMC150 as well - so hopefully, this is an easy fix - because I seriously doubt people are out there freelancing & making films and wedding videos with this AVCHD technology and producing results that have playback stutter problems...

ANY help and/or insight would be GREATLY appreciated!

Thanks! - Vince
 
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I have the same computer (but with 16gb of ram), no problems with native AVCHD/DSLR video playback. I never have FCPX create optimized media, and I recently disabled rendering to some pretty good results (I can get realtime or near realtime previews on almost everything from color corrections with multiple shape masks to simple motion graphics).

You don't have to stop the machine while it's performing analysis in the background. Working on anything simply suspends the current action and resumes when you are no longer working.

It sounds like your issue is with memory (get 16gb, it costs like $100) and your external drive - IIRC it only has a 32mb cache. I generally work on WD Caviar Black 2TB drives, they have a 64mb cache and are really fast. All things being equal the G-Drive is not going to perform as well.

I don't think anything weird is happening to the footage after importing - FCPX just rewraps it into a Quicktime container, IIRC. If you want to double check, just open the video files in Quicktime and see if they stutter there as well.
 
hey thanks for getting back...

I double checked by viewing some of the footage straight from the external hard drive and still saw some stuttering issues, but it wasn't in the same spots as it was when viewing through FCPX - but the weird thing is, when you rewind the footage (after it just stuttered) & then play it again, in most cases you won't see the stutter again (in the spot you just saw it in) so I'm starting to think that this is some kind of playback issue... maybe like you're saying the G-drive just isn't fast enough or something...

if that is the case, do you think a final exported project would come out fine? or does this definitely need to be addressed first?

So many people told me the G-drive was the best drive to go with...

I think i might import a clip into the iMac's internal hard drive just to see if that makes a difference... i just read that the internal drive will always work faster than the external... so I'm thinking if there is no stutter doing it that way, then it would have to be the G-drive right?

you import your clips proxy instead of optimized? doesn't proxy make the footage lose some quality or something like that?
all of the tutorials i watched for importing AVCHD into FCPX said to check "optimized" when importing... so that's why i did it...

I'm not familiar with this term "IIRC" - ?

thanks again...
 
IIRC = if I recall correctly

I import video into FCPX without transcoding to ProRes or ProRes Proxy. I have not run into a situation where FCPX had problems playing back the native footage. FCPX just brings in the original .mts media and puts it into a Quicktime container.

Before you reimport video, try transferring one of the clips onto your internal drive and seeing if playback issues persist. Also make sure you go through the usual troubleshooting steps - making sure your external drive isn't full, repairing permissions, etc.

Playback issues shouldn't affect a final render, but I would find it really obnoxious to edit and would want to get that fixed.
 
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I never have FCPX create optimized media, and I recently disabled rendering to some pretty good results (I can get realtime or near realtime previews on almost everything from color corrections with multiple shape masks to simple motion graphics).
Click to expand...

- if you don't import into fcpx "optimized media" - then you import proxy? as far as i know those are the only 2 options when you go to import...?


It sounds like your issue is with memory (get 16gb, it costs like $100)
Click to expand...

- do you have any recommendations as to which brand is best to buy RAM for this machine?


- those cavier drives that you use - ever have any problems? those are what you use with the AVCHD?
- i checked them out & saw that the price isn't too bad for them...

- thanks! - Vince
 
If you leave both optimized and proxy options unchecked, FCPX will only import the native files and work with those. Checking optimized gets you transcoded vanilla ProRes, proxy gets you ProRes Proxy.

OWC is generally a well-recommended brand of RAM, but I personally bought Patriots and haven't had any issues.

WD Caviar Black is generally reliable and fast. I've used them in my single drive enclosures and RAIDs and have never had an issue. As always, create redundant backups of your media.
 
Maybe move some files to your internal hard drive instead of your external, and see if the problem remains the same ... Not a solution, but might help to locate the problem. I have an iMac i5 2.8 Ghz with 8GB that I have played with AVCHD stuff on -- it my casual testing it seemed to work just fine, but at this point my primary system is still an FCP7/ProRes combination so my experience is far from definitive. I would have thought the demands were in RAM & CPU -- the actual data rate of AVCHD is not very high and so any drive should be able to keep up -- but experimenting by isolating your workflow will help. Does this problem happen with any viewer? QT gives you the same issue? Does it happen when you view in source resolution or only when upsizing to full screen? Does it happen when the file is first copied to the internal drive, then played? Is it possible you are running some sort of background tasks that interfere with the flow -- a virus checker that looks at external files? A TimeMachine that is running while you are working?

Cheers,
GB
 
There was a thread on another board talking about AVCHD files and it duplicating 3 frames at the beginning of secondary movie files (files created when the first file reaches ~2GB and starts a new file). This was caused by not stitching the movie files together properly and just importing them into Premiere Pro. You might be having a similar issue.
 
hi hendosan...
thanks for getting back...

just curious - what do you mean by "vanilla" pro res?

If you import natively like you are saying, is this better than to check either proxy or optimized?
I'm still on a major learning curve with all of this, so sorry if these questions are very basic -

I ask because i imported a 1hr clip this morning (checking optimized - and nothing else) & the background tasking went on for over 4 hours (for the import) - which i think is crazy... shouldn't the import time be roughly the time of the clip? I actually just created a thread for this to see if others are experiencing these crazy import times with this program...

i wound up getting 8g of Centon RAM (the guy at microcenter recommended it for mac over the other brands - so far so good) - i do believe i see an improvement with the stuttering issue - i didn't really have a chance to really take a look, but it does seem to be improved.... i think i saw a couple of very slight glitches, but nothing like it was (my fingers are crossed) - I have a feeling that the stutter/glitch problem was more related to fcpx itself more than anything else (& the fact that the footage was 60p) - because the playback straight from the harddrive in the QT window seems to play fine...

thanks again for all your help!

- Vince
 
hi GB -

i upgraded to 16g of ram, & this seems to have made things better...

also like you mentioned, the QT window seems to play the footage fine, so i am starting to believe that this issue (more than anything) may just have something to do with the fcpx program itself... along with using 60p - alonalthough like i said, the 16g of ram now seems to have made things better...

i know there are many issues with this program, so perhaps these are all bugs that need to be worked out - but it seems like this program is a hungry beast when it comes to memory (maybe they should recommend 16g of ram to run it instead of 4 - i don't see how this program can run on 4g of memory)

also it always seems to be doing something in the background, so maybe like you were saying that might be part of it as well...

are you using fcpx yourself?

thanks!

- Vince
 
Vince27 said:
hi hendosan...
thanks for getting back...

just curious - what do you mean by "vanilla" pro res?

If you import natively like you are saying, is this better than to check either proxy or optimized?
I'm still on a major learning curve with all of this, so sorry if these questions are very basic -

I ask because i imported a 1hr clip this morning (checking optimized - and nothing else) & the background tasking went on for over 4 hours (for the import) - which i think is crazy... shouldn't the import time be roughly the time of the clip? I actually just created a thread for this to see if others are experiencing these crazy import times with this program...

i wound up getting 8g of Centon RAM (the guy at microcenter recommended it for mac over the other brands - so far so good) - i do believe i see an improvement with the stuttering issue - i didn't really have a chance to really take a look, but it does seem to be improved.... i think i saw a couple of very slight glitches, but nothing like it was (my fingers are crossed) - I have a feeling that the stutter/glitch problem was more related to fcpx itself more than anything else (& the fact that the footage was 60p) - because the playback straight from the harddrive in the QT window seems to play fine...

thanks again for all your help!

- Vince
Click to expand...

ProRes exists in the following forms: http://documentation.apple.com/en/f...ws/index.html#chapter=10&section=2&tasks=true

ProRes Proxy
ProRes LT
ProRes 422
ProRes 422 HQ
ProRes 444

Final Cut Pro X makes only ProRes Proxy and ProRes 422 available for use.

As far as importing natively, it depends. I do it because it speeds up my workflow for most projects - less time spent transcoding is more time I could be making money elsewhere. If I need to do a lot of heavy grading or effects work however, I will transcode to ProRes (and probably work in FCP7 anyways).

As for transcoding times, I have noticed that import times scale up exponentially the longer the clip. Clips that are a couple minutes long seem to take seconds to transcode, whereas anything longer than 10 minutes seems to take way too long. This is true of my experience in FCPX and FCP7, using both my iMac and an older 8-core Mac Pro. I don't know why the length of video affects transcode time so much.
 
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