5 Replies Latest reply on Jul 12, 2015 8:51 PM by A.T. Romano

    flv frame rate/duration problem

    charles h.r73861333

      I have an flv file with a variable frame rate.  The file's duration is two hours, thirty-nine minutes, four seconds and eleven frames.  Its frame rate is 25 fps.

       

      Premiere Elements does not accept flv files.

       

      I used XMedia Recode to copy it into a PE-friendly container, specifically an mp4 container.

       

      I then pulled the mp4 file into Premiere Elements.

       

      At first it appeared to pull it in fine.  It conformed fine, I thought, etc.

       

      I put it on the timeline.  The clip's duration on the timeline was exactly what it should have been, two hours, thirty-nine minutes, four seconds and eleven frames.

       

      And that's when I noticed the problem.

       

      The video was playing back s-l-o-w-l-y.  And, when I first noticed this, I didn't notice what was perhaps the bigger problem:  The duration of the file on the timeline was the CORRECT duration of the original file, two hours, thirty-nine minutes, four seconds and eleven frames.  You will see in a moment why this was a problem.

       

      I right-clicked the file in the Project Assets window and went to Interpret Footage.

       

      At which point I discovered that Premiere Elements erroneously thought the file should play back at 20.3280 frames a second.

       

      "Well," I thought to myself, "Simple.  Tell Premiere Elements to assume a frame rate of 25 frames a second."

       

      So I put that in, and took a second look at the file on the timeline.

       

      The video was now playing back fine.

       

      But the audio was now playing way too fast.

       

      Why?

       

      Because the duration of the clip had changed; it was now two hours and nine minutes.

       

      And that's when I realized my real problem:  Even though Premiere Elements, PE, had erroneously thought the clip's frame rate was 20 frames a second, it had NOT correspondingly lengthened the clip's duration accordingly; instead, it had left it at two hours, thirty-nine minutes, four seconds and eleven frames.

       

      So when I changed the clip's frame rate to 25 frames a second, PE also did two things:  it shortened the duration of the clip to 2 hours and 9 minutes, and it had sped up the audio to fit within that new duration.

       

      So my problem is that every time I correct the frame rate I wind up with the wrong duration.  Every time I keep the correct duration I wind up with the wrong frame rate.

       

      I've tried for three hours trying to trick PE.  I've tried changing the frame rate and then going into Time Stretch to change the duration.  No dice; sometimes it works but then my frame rate is screwed up again.  Sometimes it simply refuses to take the new duration.  I have not even been able to figure out why it sometimes take the duration I'm telling it to accept and other times it just pops back to the old duration.

       

      In short, I'm stuck.

       

      I tried totally recoding and converting the original flv file before putting it into PE, taking it down a whole generation, in other words, at which point everything's fine.  But surely there's a way for me to do this without taking that drastic and quality-degrading step.

       

      I look forward to your expertise.  Thank you!

        • 1. Re: flv frame rate/duration problem
          A.T. Romano Level 7

          charles h r

           

          What version of Premiere Elements are you using and on what computer operating system is it running?

           

          The first thing that we need to clear up is your use of the description where you say that your original flv file has a variable frame rate.

          Does the file have 3 frame rates

          minimum frame rate

          frame rate (which you are calling 25 frames per second)

          maximum frame rate

           

          It seems that your issues are from the program that you used to convert the flv to presumably some sort of .mp4 file.

          There are two ways to create slow or fast motion effects in Premiere Elements

          Interpret Footage Frame Rate Section

          and

          Time Stretch

          I will not go into that now.

          Keep away from both.

           

          My suggestion is to put the original FLV through the free HandBrake program to get a H.264.mp4 version at the constant frame rate of the original FLV file.

          https://handbrake.fr/

          You should get a H.264.mp4 version of your FLV and the H.264.mp4 should have the same frame rate and duration of the original.

           

          Please let us know the outcome. I road tested this. If any problems, give details.

           

          Thanks.

           

          ATR

          • 2. Re: flv frame rate/duration problem
            charles h.r73861333 Level 1

            Thank you very much for taking a look at my message and giving me some feedback.  I appreciate your time and your help.

             

            By an unusual coincidence, your Handbrake suggestion is exactly what I first tried, and, yes, it worked perfectly.  But I find this solution unsatisfactory.  Let me quote from my first message in this thread:"surely there's a way for me to do this without taking that drastic and quality-degrading step."

             

            To me, taking the whole file down a generation and recoding and re-processing it is not a solution.  The goal is to pull it into Premiere Elements clean, without taking the video down a generation.  We all know that the video's going to be eventually taken down yet another generation when I finish editing and render the finished product.  So, before that happens, I would like to maintain as little quality loss as possible, which logically means figuring out how to work with the file in Premiere Elements in its original state.

             

            While utilizing Interpret Footage, IF, and/or Time Stretch, TS, may get a little complicated and/or time-consuming, nevertheless that is my preference if the only alternative is to take the video down a generation.

             

            I'm relatively comfortable with math; I'm prepared, if need be, to get a little in the weeds with Excel formulas and so on (though I would certainly prefer not to go that far if I don't have to).  Are there other ways, short of going into IF or TS, or taking the video down a generation, by which I can skin this cat?

             

            If not, then I would like to give IF and/or TS a shot, if you would like to walk me through the proper steps in the proper order.

             

            Let me wrap up by answering your other questions.

             

            I'm using Adobe Premiere Elements 13.  20140903.daily.717136.

             

            As for the frame rates on the original file, playing it back in VLC reveals only the one frame rate, 25 fps.  If there is a player that can reveal the presence or absence of minimum and maximum frame rates, I'm afraid I don't know what that player might be.  I took a look at the file in both VLC and GOM, and I saw the 25 framerate.  When I first got Premiere Elements, I had a discussion with some folks on the Video Help forum regarding which file types, codecs, bitrates and so on work well with Premiere Elements and which can sometimes present problems.  At that time, I was warned that if I was working with flv files, I would sometimes have to do adjustments to compensate for variable bitrates.  When I bumped into this problem with this particular flv file, I assumed they were related to a variable bitrate.  That fundamental assumption that underlies my thinking at this time could be wrong.  If that assumption is indeed wrong, then what's another way for me to solve this issue where I don't have to take the file down a generation?

             

            You suggest something that had not occurred to me, namely that the problem is NOT with the original flv file but with the software I used to convert it to an mp4 file.  Hmmm.  I used XMedia Recode.  I specifically used it because it has the capability of making perfect copies of files from one container to another with no reprocessing or recoding.  Is my thinking flawed in that regard?  Is there another way to get this flv file into Premiere Elements as a first-generation perfect copy that has merely been moved to a different container, and not recoded or reprocessed in any way?

             

            And thank you again for your help on this; I appreciate it!

            • 3. Re: flv frame rate/duration problem
              A.T. Romano Level 7

              charles h.r

               

              Thank you for the reply.

               

              I do not see that you have or can trick Premiere Elements into what you want it to do with Interpret Footage/Frame Rate or Time Stretch manuevers in this case..

               

              Consequently, have you put any focus on the program that you are using to re-wrap your FLV file's compressions in order to get at why Premiere Elements might not be interpreting the footage with the expected 25 frames per second frame rate? Have you found any significant file properties  differences (other than file extension) between original FLV and mp4 rewrapped?

               

              What video compression and audio compression are being used in the original FLV and the file rewrapped from FLV to MP4? Same, if this is just supposed to be a re-wrap. We both seem to agree that HandBrake works perfectly for converting the FLV file to H.264.mp4. But you find it unaccessable that your file must be subjected to a re-encoding progress. I am not seeing this dramatic quality hit related to the HandBrake H.264.mp4 derived from my FLV file

              video compression = On2VP6

              audio compression = MP3 Stereo

              frame size 1920 x 1080

              frame rate = 29.97 frames per second

               

              I will think about this some more.

               

              ATR

              • 4. Re: flv frame rate/duration problem
                charles h.r73861333 Level 1

                Since you suggested further examination of the theory that the problem is NOT with the original flv file but rather with the supposedly perfect copy that XMedia Recode has made of the flv file into an mp4 container, I took a close look in VLC to see if I could see any differences at all between the flv original and the mp4 copy that XMedia Recode had made.

                 

                The flv original is described by VLC as having 25 frames a second.

                 

                The mp4 XMedia Recode copy is described by VLC as having a frame rate of 20.328878!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

                 

                In other words, you were absolutely right!!!  It was the mp4 copy that was the problem, NOT the flv original.

                 

                So my question is now a different one:  How can I get a good copy of this flv file into an mp4 container?  Is there some menu you're aware of in XMedia Recode, for example, that will force a particular frame rate even on a copy that is not being recoded or reprocessed in any way?

                • 5. Re: flv frame rate/duration problem
                  A.T. Romano Level 7

                  charles h.r

                   

                  Thanks for the follow up.

                   

                  I have been in the hunt for more information on the XMedia Recode as well as other software for rewrapping FLV file.

                  I do not use XMedia Recode. And, from what I have read, it is essentially impossible to get information from the author or the site (in German or otherwise). No Forum.

                   

                  At this point, all roads seem to lead to re-encoding the FLV to H.264.mp4 which you find unacceptable.

                   

                  I will resume the search tomorrow.

                   

                  ATR