4 Replies Latest reply on Feb 14, 2011 9:49 AM by Dave LaRonde

    Trimming Video Saves Memory in After Effects CS4?

    buyer4life

      I'm working on this project, and I've got a bunch of large video files.  If I trim the video within the composition, does that save me memory  giving me longer RAM preview or speed things up?? Or would you suggest trimming it before importing it within the  composition. I'm worried if I trim the video before importing it, maybe  using VirtualDub or AfterEffects itself, I would lose the quality?

      The clip was recorded using Fraps in 'full screen' mode, and I'll be  outputting it using After Effects to 1280x720 pixels. I need  to retain the quality so people can view it later in Youtube in HD.  It's a 6-min composition.

      The problem is that the files are really large, a 2min30 sec footage  being around 3GB, and I'm not getting RAM preview longer than maybe 5-6  seconds now due to the number of files in the composition (most of them  will be used). I even turned on the multi-processor option and increased paging file memory. I was even using a 4 gig flash drive with Windows ReadyBoost.

       

      Composition Settings:

      Preset: HDV/HDTV 720 29.97 (is this the correct setting if I want to post it up in Youtube HD?)

      Durating: 6 mins

      PC: I got 4GB RAM on my system.

      Total size of files: Around 20GB, 190 files.

       

      There's one more issue, I actually need to crop the bottom/top part of the clips. For now, I've scaled the clips to exclude the top/bottom parts I don't need, but I was wondering if I should've cropped before importing them to the project. That would probably give me longer RAM preview, but then if I cropped the dimensions those clips beforehand would they lose quality? (Once again, done using AE4 or VirtualDub)

      Any help is appreciated

        • 1. Re: Trimming Video Saves Memory in After Effects CS4?
          Todd_Kopriva Level 8

          >  If I trim the video within the composition, does that save me memory  giving me longer RAM preview or speed things up?

           

          What, exactly do you mean by "trim"? Are you referring to shortening the duration of the video in the source file? That has nothing to do with RAM preview.

           

          > I'm not getting RAM preview longer than maybe 5-6  seconds now due to the number of files in the composition (most of them  will be used).

           

          The number of files used as source for a composition aren't relevant to RAM preview length, either.

           

          > I even turned on the multi-processor option...

           

          Don't do that.

           

          You only have 4GB of RAM. That's not enough for using the Render Multiple Frames Simultaneously multiprocessing feature.

           

          Also, by using that feature, you dedicate RAM to the background rendering processes, which subtracts RAM from what's available for RAM preview duration.

           

          You have very little RAM, so your RAM preview durations aren't going to be great. See this FAQ entry for some tips on mitigating this:

          http://forums.adobe.com/thread/424030

          • 2. Re: Trimming Video Saves Memory in After Effects CS4?
            buyer4life Level 1

            Thanks for the help!!  Yes, by trim I meant shortening the length of the source file. It's good that the size doesn't matter, now I'll have more editing options in my composition

            • 3. Re: Trimming Video Saves Memory in After Effects CS4?
              Mylenium Most Valuable Participant

              RAM preview duration has nothing to do with the number of layers or their duration. It is solely defined by the comp size and comp resolution setting. to increase preview length, preview at lower resolutions like half or quarter. The rest has been pretty much answered by Todd - you are making your system burst at the seams by enabling MP and it works in fact against your RAM previews.

               

              Mylenium

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              • 4. Re: Trimming Video Saves Memory in After Effects CS4?
                Dave LaRonde Level 6

                buyer4life wrote:

                 

                ....now I'll have more editing options in my composition...

                 

                Yeah, well, since you still run AE 9, you might not be totally out of the woods yet: what's the codec of this 1280x720 video clip?

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