6 Replies Latest reply on Oct 17, 2011 9:25 AM by moroccodriver

    encoding 4k to SD very slow

    moroccodriver Level 1

      I'm exporting small chunks of a 1.5hr 4k R3D timeline using the default MPEG-2 encoding setting for DVD creation.  There are 2 alternating video tracks using simple edits, and about 8 audio tracks.  I changed the color/ISO in the R3D source settings, applied an MPE-enhanced color-correction filter to change brightness, and a few clips have been altered via "motion effects" to zoom in on part of the frame.

       

      I'm running CS5 5.03 on an i7 930 with 12GB RAM and a GTX470.  I export to a sata drive that doesn't have footage on it (and isn't the C drive). The footage is on a 14TB SAS RAID-5.  I'm using the appropriate timeline for the original footage. I export directly from Premiere. I've tried unchecking boxes for maximum quality and MRQ.

       

      It takes about 1 hour to export 3 minutes of footage!    All 8 threads are at 100% and RAM is generally around 5-10GB used. The progress window usually freezes, but the processor keeps its 100% load and finishes at the time I estimated based on previous exports.

      Is this just a matter of going from 4k to SD?  Is there anything I can do to speed it up?  When I export from DV to MPEG-2, it takes less than 3 minutes.

        • 1. Re: encoding 4k to SD very slow
          Harm Millaard Level 7

          Going from around 9 mio pixels down to 345K pixels requires huge amounts of recalculation. That is why you CPU is maxed out. Add to that the only limited amount of memory, 12 GB, and it is no wonder your system is stressed out. Increasing memory will certainly help to improve performance.

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          • 2. Re: encoding 4k to SD very slow
            moroccodriver Level 1

            Thanks, Harm.  That's sad to hear, as it presents a huge drawback in my choice to work directly with the 4k files.

             

            If I switched to 24GB of RAM, should I expect the encoding time to drop by 1/2?  Or would it only make a small difference (for example from 1 hour down to 50 minutes)?  Can Premiere make use of all 24GB if I upgraded?

             

            Are there settings for memory allocation that could help me now since it doesn't seem to be using all 12GB currently? 

             

            Are there any tricks or workarounds like nesting my 4k sequence in an SD sequence or something?

            • 3. Re: encoding 4k to SD very slow
              Harm Millaard Level 7

              Nesting sequences will not help at all, because the basic problem is recalculating all the pixels from 9 mio to 345K. The problem in this case is the fabulous quality of the source material and reducing it to SD quality. People with large stills have the same problem and for them the solution is to batch resize their stills in PS before importing into PR, but with RED 4K material, I simply do not know the answer.

               

              Increasing memory will definitely help, but I can't tell you whether that will improve performance by 10 or 50%. A wild (and unsubstantiated) guess is by around 25-30% but I could be off.

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              • 4. Re: encoding 4k to SD very slow
                moroccodriver Level 1

                Okay, thanks.  It's only $175 to upgrade to 24GB, so maybe I'll try that.  I wish Premiere could use the same process that allows it to play 1/4 or 1/8 resolution in real time to export to SD in real time.

                • 5. Re: encoding 4k to SD very slow
                  Stephen_Spider Level 3

                  "Are there any tricks or workarounds like nesting my 4k sequence in an SD sequence or something?"

                   

                  I have had big render time differences when I export a HD sequence to SD Mpeg2, or drop the same HD sequence into an SD sequence and adjust the size to fit SD with motion controls before exporting to SD mpeg2.

                   

                  I don't know the mechanics and I'm not trying to contradict Harm, but I think it would be something quick to try.

                  • 6. Re: encoding 4k to SD very slow
                    moroccodriver Level 1

                    Thanks, Stephen, but I tried that and it still took the same long time.

                     

                    Just as a possible workaround, what about this:   I always create 8.5GB DVD's and then very quickly shrink them down to 4.7GB DVD's using DVDShrink.  Would it be significantly faster to create Blu-Ray files and then shrink them to regular DVD?  (so that the difference between the first two mediums isn't as huge as 4k to SD)  Is there some program that quickly shrinks Blu-Ray to regular DVD?