8 Replies Latest reply on Apr 16, 2013 8:54 AM by Jim_Simon

    Gopro qaulity drops after encoding in CS6

    arobz Level 1

      So I recently started using CS6 and have noticed that after I encode all my gopro footage the qaulity drops pretty significantly.  I have all my export settings on high and everything setup correct but the original gorpo file I edited with still looks much better then the encode.  I tried to even set the bitrates to be exactly the same and it still doesn'tlook as good as I would have hoped.

       

      Is this a problem with CS6 that people have encountered before?  I was reading somewhere you might have to encode the files to avi before going into CS6.  Seems like a total pain especially since I have my video clips already made and put together and don't want to redo it.  Anyone know of a solution for this?  Attached are my ecode settings:

       

      Framerate is at 1 because it is a motorcycle on the track so heard that is better for fast motion scenes.

       

      cs6.jpg

        • 1. Re: Gopro qaulity drops after encoding in CS6
          Harm Millaard Level 7

          Why use maximum depth and at the same time such low bit-rates?

          • 2. Re: Gopro qaulity drops after encoding in CS6
            Rallymax-forum Level 3

            The power of encoding in h.264 comes in what it can compress between full-frames (they are called I frames). These are either P-frames that use knowledge of the _P_rior frame to skip a lot of what it has to express and B-frames (with _B_oth prior and after frame information).

            You set the key (ie I-Frames) frame interval to 1 - which is kinda like AVC-Intra.

             

            At 15Mbps AVC-Intra is going to look AWEFUL.

             

            The frame-rate you have is 59.94fps.

             

            I think you might have simply mixes up the Key-Frame interval with the framerate.

             

            Also, trying to render at 1fps won't work. When played back it'll still be 1fps.

            what you need to do is make a standard sequence in Premiere at say 30fps and then drop your footage on to it. Right-click on the footage and change it's playback speed to make it play faster

            • 3. Re: Gopro qaulity drops after encoding in CS6
              Jim_Simon Level 8

              I think Rally's on to something.

               

              Uncheck "Key Frame Distance", leave everything else the same.

               

              See a difference?

              • 4. Re: Gopro qaulity drops after encoding in CS6
                arobz Level 1

                Why not?  My bitrates are not that low.  The original gopro file is 15000 so not sure what you are getting at?

                • 5. Re: Gopro qaulity drops after encoding in CS6
                  arobz Level 1

                  From what I was reading people usually do a lower key-frame interval in high motion video so that is why I set that.  Should I normally not be using that feature at all?

                  • 6. Re: Gopro qaulity drops after encoding in CS6
                    arobz Level 1

                    I just installed a new GTX card so I am going to test it now and see what happens.  Hopefully looks much better.

                    • 7. Re: Gopro qaulity drops after encoding in CS6
                      Rallymax-forum Level 3

                      arobz wrote:

                       

                      From what I was reading people usually do a lower key-frame interval in high motion video so that is why I set that.  Should I normally not be using that feature at all?

                      You are correct. For high motion video it will be better to have more complete frames (ie I frames) since the in-between frames are going to struggle.

                      But you have to compensate with a higher bitrate to cater for more bit-laden I frames vs smaller B and P frames.

                      For example, AVC-Intra (which is AVC at keyframe 1 with some other rules) is done at 50 or 100Mbps. At 15Mbps it's going to fall apart. There simply isn't enough bits to make 30 or 60fps of I-frames without having to make some pretty ugly compression artifact decisions.

                       

                      Stepping back 1000 feet for a second... what is the goal here?

                      If it's to make master edits for use later then you should be saving it to a digital intermediate like DNxHD.

                      If it's for archiving then AVC-Intra50 is a good balance of size and quality and ease of editing.

                      • 8. Re: Gopro qaulity drops after encoding in CS6
                        Jim_Simon Level 8

                        You are correct. For high motion video it will be better to have more complete frames (ie I frames) since the in-between frames are going to struggle.

                         

                        That really applies more to acquisition than to delivery, though.  It's quite normal to leave that setting off and use the normal 1/2 second keyframe interval.