7 Replies Latest reply on Mar 26, 2008 3:26 AM by Jonas Hummelstrand

    Quicktime stutters

      Hi,
      If I render a larger file as quicktime best quality, the playback stutters. The same project rendered as AVI doesn't do this can anyone tell me why? Can I fix this? Thanks...........dave
        • 1. Re: Quicktime stutters
          Andrew Yoole MVP & Adobe Community Professional
          Please provide more details about the files in question: file size, duration, and codecs used.

          Typically, files that stutter do so because standard computer hard drives are not fast enough to output the high data rate that some video codecs require. If you're rendering your files uncompressed, odds are your hard drives aren't able to play them without dropping frames.

          You can always render a second copy of the output file for test playback purposes - I usually use Quicktime Photo-JPEG for that purpose.
          • 2. Re: Quicktime stutters
            Mylenium Most Valuable Participant
            As Andrew explained - all that matters is the final data rate. Uncompressed movies rarely ever play back smoothly even on the most powerful systems. Presumably you used a different CoDec for the AVI, thuis reducing the data rate already, but you didn't do so for your QT. Also consider that QT is never as quick on PCs as AVIs simply because it's not natively integrated in the operating system. In addition, Apple are somewhat negelcting the PC platform recently and QT is not really well optimized there.

            Mylenium
            • 3. Re: Quicktime stutters
              Level 1
              Thanks for the reply, I have a Quad core cpu 3.24GHz , my O.S. is on a 10k 150GB Raptor hard drive,4GB 1066 ram (until I go 64 bit) The same file rendered AVI, and Quicktime. The AVI is 2.98GB 720x480 1411kbps uncompressed, plays great. The Quicktime file is 2.67GB Animation, Best, and stutters(mildly). I tried your advice Andrew on rendering Photo-JPEG, and that plays fine. So I guess I'll use your method of rendering both If I want to use Quicktime, and then test playback. Thank you both for your help!..........................dave
              • 4. Re: Quicktime stutters
                Jonas Hummelstrand Level 2
                To save render time, you can highlight your uncompressed Output Module in the Render Queue and hit Ctrl-D / Cmd-D to duplicate it and set the second one to a compressed "preview" codec. That way you get both files in one render (with minimal render time increase.)

                - Jonas Hummelstrand
                http://generalspecialist.com/
                • 5. Re: Quicktime stutters
                  Level 1
                  Awesome tip, Thanks!
                  • 6. Re: Quicktime stutters
                    David Wigforss-Hv1BNN Level 2
                    Jonas, to save even more time, you can use the uncompressed render as the source for the "preview" render.

                    When the uncompressed render is setup in the render queue, drag "Output Module" onto the project window to create a placeholder. Drag the placeholder back into the render queue and set it up to render the "preview" version.
                    • 7. Re: Quicktime stutters
                      Jonas Hummelstrand Level 2
                      David,

                      I doubt that would be quicker, since dumping the frame buffer in RAM to two files should be quicker than reading the uncompressed rendered file from disk and then writing it in compressed for to disk again. I haven't timed it, but I'm willing to bet an Adobe-labeled WiFi finder keyring that I'm right. Prove me wrong! :-)

                      - Jonas Hummelstrand
                      http://generalspecialist.com/