AVCHD Editing

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Barry Hunter
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Joined: Nov 30 2001
I`m currently editing a Dance Show shot on 5 AVCHD Cams, 3 x HXR-NX5e`s, 1 x HXR-NX30e & 1 x HXR-MC50e. My editing PC`s specs are:-
Intel i7 @ 2.80Ghz 4 core processor
NVIDIA GeForce GT 430 graphics card
6Gig Ram

When in Multicam I experience quite a bit of stuttering however, when I revert to normal mode it plays OK! So the way I`ve been editing is to go into MC, perform the edits, back to normal to check & then back to MC to continue.

Am I expecting to much from this set-up? And what if any changes can I make to improve this. I spoke to the support of the company that built the system in late 2010 & they said, "wait around 6 months for the new processors to arrive"

So, any ideas guys?

 

Barry Hunter videos4all.org

Mark M
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Joined: Nov 17 1999
Re: AVCHD Editing
And your NLE is....?
Is your media on the same disk as your OS?

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johnd
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Joined: Mar 8 2009
Re: AVCHD Editing
Have you tried reducing the monitor window resolution?
Barry Hunter
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Joined: Nov 30 2001
Re: AVCHD Editing
Editing using Edius vers 6.05, media stored on 2 x separate drives plus a further data drive for music etc.

Barry Hunter videos4all.org

sleepytom
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Joined: Sep 15 2000
Re: AVCHD Editing
Hi Barry
 
When you edit in multicam your computer attempts to decode all your separate cameras at the same time. To decode each stream requires the hard disk to seek to the needed frame and pass it to the CPU where it is decompressed before being sent to the graphics card for display. If there is a bottle neck somewhere then the graphics card will not get the next frame for display in time and the output will stutter as it drops or repetes a frame. 
 
In normal edit mode only the currently displayed clip is decoded and so the resource usage is much lower, reducing the chance of dropped frames and their associated stutter. 
 
Looking at your system the likely bottlenecks could be..
hard disk speed (drives cannot supply frames in time to the CPU)
CPU Power (cpu too slow to decode multiple streams of AVCHD in time)
General resource crisis due to internal transfer speeds / lack of ram. 
 
It should be fairly easy to work out which of these is your issue. 
First lets try the CPU. AVCHD is a difficult codec to decode, so the CPU works hard to decode multiple streams. You can try converting your cameras rushes to an intermediate codec such as Edius' own HQAVI which is much easier on the CPU. The hqavi files are much larger than AVCHD which is good for the CPU but bad for the hard disk, so ensure that your running your test clips from fast hard drives (if you have more than one drive then spread out the rushes over your available drives, as this reduces the seek time overhead).
 
If using an intermediate codec doesn't improve the smoothness significantly then it is most likely to be a hard drive bottleneck.  Multicam is very taxing on hard drives due to the amount of seeking between the different streams on the disk.  If your drives cannot keep up then you'll drop frames and get stutters. Upgrading to some SSD storage for your media drives would make a huge difference. As SSDs have much faster seek times than spinning drives a single SSD can outperform multiple spinning disk drives and should smooth out your multicam process I've had very good results from this drive - 256GB is enough space to keep all the rushes for a decent length edit.  
 
General performance issues can be addressed in a number of ways. You should be sure to use a 64bit OS and the 64bit version of Edius, this will ensure that you can access all the RAM in your system. I'd suggest adding more RAM really i7 CPUs need at least 2GB per core to run at full speed, more is obviously better and RAM is quite cheap so it is a good value option to get a 16GB or 24GB set of matched RAM for your system. Obviously you should do all the basic good practices for running an edit suite, turn off antivirus whilst editing, don't run other apps / utils at the same time as your edit software (things like skype, itunes etc - quit them and make sure they have actually exited rather than just hidden themselves as seems to be popular with these kind of apps!)
 
 Give the intermediate codec option a try, this might work and give you smooth video for nothing (except the conversion time). You might find that even with an SSD the hqavi codec performs significantly better than native AVCHD. The future holds specific GPU/CPU decoding hardware which works very well on the latest ivybridge CPUs if you have software which supports it (I don't know if there is a version of Edius with support for these CPUs??)
 
I hope this helps
cheers
tom
 

You can contact me at http://tombassford.org
People interested in live production might like to check out http://atemuser.com 

Barry Hunter
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Joined: Nov 30 2001
Re: AVCHD Editing
Hi Tom
Many thanks for your extremely comprehensive reply. Having 2 data drives I should have put the media across both but for some stupid reason I didn`t. The project is a dance show in a similar vein as "Strictly" and is over 3 hrs long on 5 cams! I`d thought of converting the media to Canopus HQ but I think I would have run out of space. System is 64bit although I seem to think that Edius is 32bit, if that`s the case would extra RAM help?
 
I`ve almost finished the edit (29 routines plus 3 competitions & medal presentation) so I`ll do some experimenting once I`m done. Thanks again for your advice. 

Barry Hunter videos4all.org

Arthur.S
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Joined: Jun 2 1999
Re: AVCHD Editing
To take advantage of more RAM Baz, the software needs to be 64bit too. While on the subject of things computer, I've just come across this on another forum: God Mode.{ED7BA470-8E54-465E-825C-99712043E01C}
Put a new folder named as above on the root of your C:/ drive, create a shortcut to it on your desktop. You now have easy access to every tweak possible on your PC. The icon looks cool too! smiley
Tony Carter
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Joined: Oct 15 2000
Re: AVCHD Editing
Thanks Arthur. yes

TonyC

Arthur.S
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Joined: Jun 2 1999
Re: AVCHD Editing
WARNING! DO NOT do this on a Vista 64bit system. Crashes Windows explorer. Works fine on 32bit.