8 Replies Latest reply on Sep 20, 2010 9:39 PM by mufananidzo pamberi

    Benefits of more than 1 Pass?

    Rkenosha Level 1

      Just a quick question. Are there any benefits to using more than one pass when encoding high-quality mpeg 2 video. I am starting out with NanoFlash files that are recorede at 180MPS.

      Thanks Roman

        • 1. Re: Benefits of more than 1 Pass?
          Harm Millaard Level 7

          Each pass improves quality at the cost of encoding time. Ideally one would have the option to choose a number of passes between 1 and 9 line CinemaCraft. The most noticeable this is on hard to encode parts like leaves moving in the wind, ripples on water, high speed objects, etc.

          • 2. Re: Benefits of more than 1 Pass?
            Rkenosha Level 1

            Harm,

            Thanks for the reply. So if I have the time, multi pass encoding is the way to go. Normally, I will let it encode overnight.

            Roman

            • 3. Re: Benefits of more than 1 Pass?
              the_wine_snob Level 9

              Yes. Multi-pass will yield better results, especially with motion, either camera, or subject, as Harm points out. The only loss is the time to Transcode.

               

              Some users ponder how Hollywood gets such good Transcodes. It's very expensive, multi-pass encoding (as Harm also mentions), and that software is run by highly-trained professionals, who do nothing else all day - every day.

               

              In our general case, we only have the option of 2-pass VBR, instead of 9 - 20-pass VBR.

               

              If you have low-motion footage, then 1-pass CBR will just fine. Add much motion, and those scenes will benefit from the second pass.

               

              Good luck,

               

              Hunt

              • 4. Re: Benefits of more than 1 Pass?
                John T Smith Adobe Community Professional & MVP

                A couple of other products to consider...

                 

                CCE Basic for coding http://www.cinemacraft.com/en/
                or Grass Valley Procoder http://www.grassvalley.com/products/procoder_3

                 

                From what I've read, the "big" CCE coding program does multi-pass work... for a multi-large price

                • 5. Re: Benefits of more than 1 Pass?
                  Jim_Simon Level 8

                  You'll get better end results using the free HC Encoder in CQ mode.

                   

                  CQ (or Constant Quality) is the true professional way to encode.  Unlike VBR, CQ will actually use only the bits necessary to encode the frame at the desired image quality.  While it may sound like this is what VBR should do, the specification of a "target" bitrate means the encoder will do it's best to hit that target, even using bits it doesn't need to to get there.  So while VBR has some freedom, it is still a constrained encoding method.  This is why multiple passes are often required.

                   

                  With CQ mode, you require only one pass.  The encoder will use whatever bitrate it needs to to reach the desired quality setting, regardless of bitrate.  (Of course, DVDs have a limit to the bitrate they can use, so if such is your end goal, you can specify an upper limit.  When the bitrate required to reach a specified quality setting goes beyond that limit, then the encoder will reduce the quality to keep the bitrate within specs.  This may sound like a bad thing, but CBR and VBR are doing the same, and worse, to your footage.)

                  • 6. Re: Benefits of more than 1 Pass?
                    expeditionwest Level 1

                    Bill ?

                     

                    I thought WE were the highly trained professionals.

                     

                    We'd have to be to get CS5 working as well as we do (when we do)

                     

                    expeditionwest

                    • 7. Re: Benefits of more than 1 Pass?
                      the_wine_snob Level 9

                      Well, not sure about you, but I do not make the same $'s, as those Hollywood folk!

                       

                      Also, no one has handed me a 20-pass encoder, and said, "have at it."

                       

                      Hunt

                      • 8. Re: Benefits of more than 1 Pass?
                        mufananidzo pamberi Level 1

                        Jim,

                        Do you have workflow guidelines for using the HC encoder? I have 1080p25 source material in PPro CS5 that I would like to convert for DVD authoring in Encore.

                        Thank you.