29 Replies Latest reply on Oct 9, 2013 8:37 AM by Szalam

    Issues with Size of FLV VBR 2-pass vs 1-pass Encoding in CS6


      Hey Everyone,


      I've been doing some testing on various systems (using either Windows 7 or Windows 8 Consumer Preview) using Premiere Pro CS6 as well as Media Encoder 6 and I've noticed that encoding FLV files using VBR 2-pass encoding produces a file that is significantly larger than the same source file encoded using just a VBR 1-pass.


      For example, one test that I ran used 10 seconds of DVCPRO HD 720P 29.97 footage as source material. I exported all clips exported as .flv, 960x540 square pixels, 29.97 fps, 1000 kbps and everything else left at default settings.


      Here were my results:


      Size of Export via Premiere Pro CS5 VBR 1pass: 1.564 MB

      Size of Export via Premiere Pro CS5 VBR 2pass: 1.618 MB

      Size of Export via Premiere Pro CS6 VBR 1pass: 1.450 MB

      Size of Export via Premiere Pro CS6 VBR 2pass: 3.622 MB


      Eric Addison of 100 Acre Films also ran a similar test on his system and got these results:

      Encoding 10 secs of a P2 AVC-I 1280x720, 29.97 clip using the same settings as above to FLV


      Premiere CS6 Export VBR 2 pass – 2.87 MB

      Premiere CS6  Export VBR 1 pass – 1.55 MB

      AME 6 Export VBR 2 Pass – 2.85 MB


      I've tested this out with short clips, ~3 min sequences, raw clips, and clips with lots of effects, and I continue to get consistent results with the VBR 2-pass file being anywhere from 30% up to 300% larger than the same clip encoded using just 1-pass encoding. Again, this doesn't occur using Premiere Pro CS5 or 5.5 (or AME 5), so it appears to be just an issue within CS6.


      Would anyone else be willing to run a similar test using their system and own source files and post your results in this thread to determine if this is a system-wide issue or just flukes?



      Kevin Tostado

      Tostie Productions