Videos shot on Canon Vixia HF R20 are jerky on iMac. Do I need more RAM?

Question

Level 1

8 points

Videos shot on Canon Vixia HF R20 are jerky on iMac. Do I need more RAM?

Hi. I have a new Canon Vixia HF R20 video recorder. I learned here how to upload videos, but they are very jerky. The first few frames seem OK but then the sound continues and the picture remains frozen, then even the sound breaks up. The red bar continues smoothly to move across the thumbnails. Should I have more RAM or something? I have closed all other progams and restarted but this does not help. I have 10.5.8 and the following:

Model Name:	iMac
Model Identifier:	iMac8,1
Processor Name:	Intel Core 2 Duo
Processor Speed:	2.4 GHz
Number Of Processors:	1
Total Number Of Cores:	2
L2 Cache:	6 MB
Memory:	2 GB
Bus Speed:	1.07 GHz
Boot ROM Version:	IM81.00C1.B00
SMC Version (system):	1.29f1

Thank you in advance!

Mac OS X (10.5.8)

Posted on Jan 16, 2012 5:59 PM

Reply

Answer 1

babowa

Level 9

78,568 points

Jan 16, 2012 6:07 PM in response to XLVII

Is your footage HD? Or what is the pixel size of your videos? I see you have 2 GB, which is at the low end for processing video, especially if it is HD. I have 12 GB and find that is better. I'd at least double yours or max it out; see OWC (macsales.com):

http://eshop.macsales.com/shop/memory/iMac/Intel_Core_2_Duo_PC2-6400

As you can see, Apple officially supports 4 GB, but OWC has tested 6 GB, so the decision is yours.

Reply

Answer 2

XLVII Author

Level 1

8 points

Jan 16, 2012 7:05 PM in response to babowa

How do you have 12 GB if only 4 are supported? Does that work? My camera is still at its default settings of whatever density, but it touts itself as an HD device, so I imagine it is in HD from the box. I'll check it out.

Reply

Answer 3

babowa

Level 9

78,568 points

Jan 16, 2012 7:08 PM in response to XLVII

Sorry if I didn't make that clear: my iMac is a mid 2010 and supports 16 GB - I have 12.

Reply

Answer 4

samberl

Level 4

2,007 points

Jan 16, 2012 9:15 PM in response to XLVII

If you are importing video at full HD resolution, your iMac will struggle trying to process it.

It's best to down sample your HD video to 960x540 during import. Unless you really need full HD, 960x540 quality will suffice.

To process full HD video at 1920x1080 requires a major hardware upgrade, you are looking at a quad-core iMac or a Mac Pro with a minimum of 8GB RAM but preferably 16GB and fast hard drives.

Reply

Answer 5

babowa

Level 9

78,568 points

Jan 16, 2012 9:25 PM in response to samberl

Actually, amazingly enough, my previous iMac - 2.16 GHz and 3 GB RAM (maximum) from 2006 - did process my HD footage, but it was s-l-o-w. I generally shot at the other setting (1280x720), which not only made the file size much smaller, but I could actually wait for the rendering. But, yes, it was still much, much slower than my new iMac.

Reply

Answer 6

XLVII Author

Level 1

8 points

Jan 20, 2012 4:05 PM in response to samberl

Thank you. I will give it a try as soon as I clear all the fallen trees from my yard. Ice storm. I don't need really high res anyway since I will be viewing on the Mac anyway at a smallish screen size.

Reply