4 Replies Latest reply on Apr 10, 2011 10:22 AM by panos pan

    Queue vs. Export - some observations

    jdmack01 Level 1

      One of the new features in Premiere CS5 is the ability to export media directly from Premiere without going through AME.  At first, I thought that it probably didn't matter which method one chose, but I now know that it does.

       

      For my test, I was working with a standard .avi file of 4:37 duration with no effects.  For my export setting, I used Premiere's H.264 YouTube SD preset, except I changed the frame rate to 29.97.  "Use MRQ" and "Use Previews" were unchecked.

       

      First, I sent the timeline to AME, and left Premiere running in the background.  CPU usage was between 90% and 97%, and of my 8 GB of memory, 4.68 GB were being used.  Output time: 2:39.  File size: 69 meg.

       

      I repeated this test, but closed Premiere once the encoding began.  CPU usage stayed the same, but memory usage climbed to 5.4 GB.  Hmmm.  Fewer applications running, but greater memory use.  Output time: 2:42.  Apparently, memory usage has no effect on encoding time.  File size: 69 meg

       

      Next, I ran the test using the "export" button rather than going through AME.  The first time, I had MPE set to "software only."  CPU usage was about the same as it was with AME, but memory usage was only 2.40 GB.  Output time: 2:10!  File size: 70 meg

       

      Then I set MPE to "GPU Acceleration."  Now my CPU usage dropped to between 80 and 90%, memory usage stayed around 2.6 GB, and the output time - 1:36!!  File size 78 meg (hmmm).

       

      Maybe I've been misreading the articles about MPE, but I didn't think it was supposed to effect encoding.  From my test, it appears that it does from within Premiere, but not from within AME. And why the final file would be significantly larger when encoded using MPE, I don't know.

       

      Conclusion - "Export" is a better choice over "queue" for a single output file.

       

      J. D.

        • 1. Re: Queue vs. Export - some observations
          Colin Brougham Level 6

          Maybe I've been misreading the articles about MPE, but I didn't think it was supposed to effect encoding.

           

          To be specific, hardware MPE doesn't affect encoding, but it does accelerate rendering (and playback). This also pertains to things like scaling, deinterlacing, and colorspace conversions--all are accelerated by hardware. When you use hardware MPE, you're taking the load off the CPU for certain activities and giving to the GPU. The result is that the CPU is able to work more efficiently, since it's only doing one task: encoding. The net result is that encoding is (or usually is) faster with hardware MPE than with software alone. Practically speaking, though, the encoding times are probably close to identical; it's the rendering of the composited image that is the resource hog.

           

          From my test, it appears that it does from within Premiere, but not from within AME.

           

          Jeff's post sheds a little light on this (this is a known issue/limitation): Not Getting the Quality You Expect From the Adobe Media Encoder?

           

          And why the final file would be significantly larger when encoded using MPE, I don't know.

           

          Again, you have to be specific: hardware MPE. MPE is always in use in Premiere, regardless of whether you have the appropriate hardware or not. The difference in final encoded file sizes is due to the fact that a hardware-rendered or Maximum Render Quality software-rendered composited frame is of a fundamentally different quality level than what is handed off by a non-MRQ software rendered frame; the former tends to be sharper and decreases encoder efficiencies a little bit, resulting in a slightly larger final file. The increase in quality is worth it. The take home is that you could potentially knock the bitrate down a little bit with hardware- or MRQ-rendered exports.

          • 2. Re: Queue vs. Export - some observations
            panos pan Level 1

            Hi i have something to mention on this.I tryed to export a full project from avcd 1080-1920 to 720-576 mpeg 2 dvd.I know that this conversion create more blur the final output video 720-576 so i put a sharp 10% on the first avchd video.I use m.p.e with n vidia 470.If i send the file to queue with prm closed, i take a blur video,in 45min,with 5,5g of ram working.If i export from prm immediately i take a much better video,working 2.9g of ram no blur at all and of course i can see the 10%sharpness.

            Both of videos are export only with "use preview "CHECKED in prm dialogue.No comment.i7 12g ram gtx 470 raid ,asus p6t.

            • 3. Re: Queue vs. Export - some observations
              Harm Millaard Level 7

              Colin,

               

              FYI, there is a serious slow-down with using the queue versus direct export, most notably with SD DV exports to AVI.

               

              The Disk test in PPBM5 contains almost one hour of standard DV AVI material, no effects, no transitions. Nothing. Exporting to MS DV AVI with:

               

              Direct export takes 19 seconds on my system, and using the queue takes 64 seconds. There is no encoding involved, no rendering, no scaling, no blending, nothing at all. Just a simple export of 13 GB to disk. I have repeatedly asked for reasons behind these results, but it has been utterly quiet on the front and I do not understand the reason for it.

               

              Allegedly both use the same export module, but this has been the case since 5.00 and nobody has explained these huge differences yet.

              • 4. Re: Queue vs. Export - some observations
                panos pan Level 1

                Something new i just found!! Working in avchd always,1 min video from 1080-1900i to mpeg 720-576 with sharpen 10%.If the mpe is enable the difference between the queue and the export is that that the video made from queqe is a bit messy(IN THIS MODE SHARPEN IS ACCELERATED FROM MPE).If the mpe is disable the two files are very clean and same its other(IN THIS MODE SHARPEN IS RENDERED).Finaly i realized that if you queue export and working with mpe the exported file has been effected (always in avchd 1080 i because in sd works fine!!) If you queue export in software mode the file is correct.Why that ??