View Full Version : rendring video in fx tree?

10 October 2009, 07:46 PM
is it simply not a good idea or am i doing something wrong?

i'm making some tests and when i render an avi it takes almost 3x as long to play as i should. for example a 3 sec clip(100 frames @29.7) plays for 8 sec. i'm using 6.5 also if that makes a difference.

sorry if this a little vague, i'm just really confused atm.

10 October 2009, 03:32 AM
Problem is your codec (or lack of one) and computers in general not able to play uncompressed footage realtime. If you need to deliver final product, render that with lossless codec or uncompressed. Lossless compression is like .zip or .rar; you aren't deleting anything, just compressing it.

To deliver to editor for broadcast, I use QT:Animation codec. To play on my computer, try qt:photo jpg codec.

In order to get multipass/variable bit rate, I belive you need to reencode your video outside of FX Tree in a dedicated compression program.

10 October 2009, 04:02 AM
thanks for the reply. after playing around some more, i was wondering if it might not have something to do with the codec. in an earlier test tho i tried qt as well and it just locked up the player. i tried a new test tonight in nuke(ple) and the qt ran fine.

another thing is the file size is huge using the fx tree. i think i had the same settings w/ nuke?

i'm working on a group project were my part is to put all the clips together and this is basically my first time working with animation. i'll be needing to composite some things in and that's were my tests come in. so final product is the goal.

i don't understand how i can render to zip or rar tho, without rendering to mov or avi first?

10 October 2009, 12:53 AM
ok, figured out the problem. it wasn't so much with the codec, but the settings for it. by default mov is set to key frames every 24 frames and avi every 15 frames. changing either to 1 makes all the difference. i suppose just unchecking that box would do the same but didn't test that yet.

i don't understand what the purpose of those settings are but i would thing it would be set right as default. anyway, thanks for not just calling me an idiot off the bat. :-)

10 October 2009, 02:12 AM
keyframes means when the codec stores a full image, instead of the just the difference between images. So more keyframes means larger files and more bandwidth required.
my guess is that you were probably not setting the codec and rendering uncompressed, which means large and slow files.

10 October 2009, 02:37 AM
in that case, wouldn't setting it to key every 1 frames be more than every 15 frames? if i'm understanding right, for 300 frames total, keying every 15 frames would yield 20 full frames and keying every 1 frames would yield 300 full frames. granted there's a several hundred mb difference, but it's happening the other way around.

i'm happy it's working now, but still confused as to why. sorry for being so dense but animation is completely new to me.

10 October 2009, 06:52 PM
I think is happening is that if you don't do anything to pick the codec, it will use uncompressed. As soon as you opened that dialog, then you've chosen a codec - by default "Video" I think - and now your tweaking its setting. 1 key every frame will result in very large file.
for exporting CG to compositing, it's best to use the "Animation" codec, which is lossless

10 October 2009, 07:54 PM
lol, that's just it tho. if i just pick .mov and render, i get a file over 600mb and it locks up when i try to watch it. if i open up codec and change it from 24 to 1 i get a file less than 20mb that plays fine. animation is the default and quality is set midway. maybe i'm being thick headed and not seeing it right and it'll make sence sometime down the road?

10 October 2009, 09:16 PM
Again, there are delivery codecs and viewable codecs. For delivery, quality i the upmost important; filesize doesn't matter. Use QT:Animation - and make sure to set to 100% best quality. If it's lower than 100/best, then it's no longer lossless.

After that, reencode with another program for divx/xvid avi's, or h264 qts to watch it. Also might wanna try wmv, but i'm not too familiar with it...


10 October 2009, 12:37 AM
yea, i'm not concerned with file size as long as it plays good. just using that to try to understand the algorithm(?).

i prefer qt for myself but think it's going to need to be avi for the finished product and i hate re encoding anything more than necessary. right now i'm just testing the waters so i don't fall behind once i start getting scene clips.

i really appreciate all the feed back ya'll have given me. thanks again.

peace, kirk

10 October 2009, 03:47 PM
I was looking for a qt compression tutorial I remember reading a while back. Instead I found a h264 qt encoding tutorial. Well, after breezing over the comments saying the tutorial sucked (didn't even mention bit rates......) I was about to give up, but then I read on how you should skip qt entirely (and not pay Apple for qt pro); Hx264 isn't tied to QT and you can encode to it for free. After recommending doom9, I give you this hx264 encoding tutorial:

But remember, h264 is lossy and shouldn't be used for final delivery (it's like copying vhs tapes; you lose quality each time you encode to lossy).

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