Dropping frames while multiclip editing

Question

Level 1

0 points

Dropping frames while multiclip editing

Whenever I edit a multiclip it plays for a few seconds and I am able to cut to the different cameras with no problem. BUT...after just 5 seconds or so it drops frames and nearly freezes. Both clips are ProRes 422 and shot from identical cameras.

It's dropping frames on both computers I've worked on: my MacBook Pro, 2.15 Ghz, 2 gigs RAM..AND a MacPro dual 3-ghz, 16 gig RAM machine.

I'm sure it's a setting I'm missing somewhere but can't figure it out. I've tried it with both Safe RT and Unlimited RT checked but it makes no difference.

Any insight greatly appreciated.

Posted on Nov 16, 2009 4:49 PM

Reply

Answer 1

David S.

Level 7

20,630 points

Nov 16, 2009 4:53 PM in response to Jim Rogalski

Your dedicated media drive has great effect on editing multiclips using pro res, especially at HD quality.

Using any external drive, FW400 or 800, will cause issues.

What are you using, with what sequence setting, frame rate and pixel grid size for the video

How many streams

Reply

Answer 2

Jim Rogalski Author

Level 1

0 points

Nov 16, 2009 5:02 PM in response to David S.

Yes, I'm using a firewire 400 external hard drive. The frame size is 1920 x 1080.

As for other settings, what I've done is drop the multiclip into a new sequence and answer "yes" to the message about changing the sequence settings to match the clip settings.

Reply

Answer 3

Jim Rogalski Author

Level 1

0 points

Nov 17, 2009 4:29 AM in response to Jim Rogalski

So if I have to use a firewire drive for my media, what can I do to stop dropping frames in multicut?

Is it an issue with Pro Res? If so, what is the best codec to use for clips that will be multiclipped?

I'd like to get this problem solved as soon as possible and any help will be immensely appreciated.

Reply

Answer 4

Studio X

Level 7

27,229 points

Nov 17, 2009 6:44 AM in response to Jim Rogalski

So if I have to use a firewire drive for my media, what can I do to stop dropping frames in multicut?

Use a RAID 0 FW 800 drive. It should provide a throughput around 70MB/s. Your FW400 drive is probably producing 30MB/s or less.

Is it an issue with Pro Res? If so, what is the best codec to use for clips that will be multiclipped?

It is an issue with what the hard drive system can provide and the computer can process. ProRes was intended as a lower resolution option to *Uncompressed HD formats*. It is more demanding (heavier bitrate demands on the hard drive) than HDV, AVCHD and the other mpeg based acquisition formats. People like ProRes because it moves them out of a Group of Pictures (GOP) codec to an all "i" frame one at the cost of increased hard drive space and a more demanding throughput.

'd like to get this problem solved as soon as possible and any help will be immensely appreciated.

Convert everything to DV and your drive may function ok.

Get a RAID 0 drive from a manufacturer who makes drive systems for video editing and connect it via FW800.

If you have a computer that allows for external cards, get an esata card and connect an esata RAID 0 device.

Have fun.

x

Reply

Answer 5

Jim Rogalski Author

Level 1

0 points

Nov 17, 2009 7:15 AM in response to Studio X

Thanks Studio X. I'll give your sugestions a go and report back.

Reply

Answer 6

Jim Rogalski Author

Level 1

0 points

Nov 17, 2009 3:35 PM in response to Jim Rogalski

SUCCESS! I am now able to perform multiclip editing as fast as my fingers can click!

Thanks Studio X for the insight.

I converted my Apple Pro Res 422 HD files to HDV1080i50 in one test, and to HD1080p24 in a second test and both times I was able to click back and forth in the multiclip viewer and not a single dropped frame! And all of my edits took.

I used Edit>Export>Quicktime Conversion rather than Compresor to transcode the files.

Time consuming for sure, so my follow up question is: is there a way to transfer files directly from the camera to one of the codecs above? When choosing Log and Tranfer the only options are Apple Pro Res 422 or P2 AVC-Intra Native.

Thanks again for the insight Studio X.

Reply

Answer 7

Broca

Level 1

0 points

Jan 14, 2010 11:13 AM in response to Jim Rogalski

Hi everyone,

I would like to know why I'm having the same problem but with 3x1TB - RAID 0 editing 2 layers HDV1080/60i multiclip?
The video stuttering when I try to change angles between 2 scenes, so I have to stop the video and play again to change another angle and all over again and again.
I'm trying many forums and nobody answer me!
Please, somebody help me, please!!!!

Reply