13 Replies Latest reply on Jan 12, 2012 8:31 AM by Ekeroil720p

    Drifting out of sync audio in PE10 (h264 sources)

    Ekeroil720p

      I am having issues with certain h.264 clips recorded with a Hauppauge Colossus internal PCI card at 720p: when I export the final movie, longer (2min +) clips can go out of sync up to 1-2 seconds, depending on clip length. This is in the recently purchased Premiere Elements 10 by the way. Yes, I know H264 is not the best editing format but I have few choices because of image quality and handling of huge files.

       

      The project format I use is AVCHD 720p and there is no red strip above the clips (except when using effects obviously) so I believe the captured material is in its "native" format.

       

      Here is the real kicker: when previewing said sequence in PE10 (space key), everything is fine and perfectly in sync. The problem only occurs when exporting. So far I've tried:

       

      * exporting to different formats (WMV, QT, etc)

      * adding cuts every 10-20 secs in the offending clips

      * time stretched them to 99.9% or 100.1%

      * unlinked audio and video and moved them to different tracks

      * forced a fixed framerate on the source videos - which helps in certain situations

      * used different bitrates and formats (fixed & variable bitrates) in the capture software

       

      What I haven't tried but I'd rather not is:

      * export WMV/QT at highest setting from the capture software and edit that (quality loss and intermediate footage)

      * split the .TS h264 file into its Video and Audio components (intermediate files and disk space issues)

       

      AFAIK, this issue did not happen in PE9.

       

      Any input and suggestions are warmly welcomed!

        • 1. Re: Drifting out of sync audio in PE10 (h264 sources)
          Steve Grisetti Adobe Community Professional

          This is a common issue with video from Hauppage devices, which produce non-AVC H.264.

           

          I don't know that there is a solution. Premiere Elements is designed to interface primarily with camcorder-based video.

           

          You may want to look into a program like Quicktime Pro instead.

          1 person found this helpful
          • 2. Re: Drifting out of sync audio in PE10 (h264 sources)
            Ekeroil720p Level 1

            Thanks for replying Steve. Can't really go the QTPro way since there's too much editing going on - or did you mean for transcoding the captured material to another format? I'll have to simply render the faulty clips from Hauppauge's software then. Luckily it happens very rarely but it's so frustrating to see everything in sync when you preview then the sh't hits the fan when you export.

             

            This made me think it was a problem within Premiere. Luckily it's only happened with maybe 20% of the clips if not less.

             

            Another observation is that Premiere is reporting odd framerates for those clips, like 265.7fps and the like.

            • 3. Re: Drifting out of sync audio in PE10 (h264 sources)
              Steve Grisetti Adobe Community Professional

              This is typical with this type of non-standard, non-camcorder video.

               

              Maybe Bill or Neale or someone has a suggestion.

              1 person found this helpful
              • 4. Re: Drifting out of sync audio in PE10 (h264 sources)
                nealeh Level 5

                That comment about high framerates strikes a chord - try searching the knowledge base.

                 

                The only other suggestion I can make is to:

                • unlink video / audio
                • export audio
                • convert audio to .wav 48KHz 16-bit PCM (the free Audacity can do this)
                • delete original audio from timeline
                • add the PCM audio to timeline.

                Several steps, but it really takes very little time to do.

                 

                Cheers,
                --
                Neale
                Insanity is hereditary, you get it from your children

                • 5. Re: Drifting out of sync audio in PE10 (h264 sources)
                  Ekeroil720p Level 1

                  Cheers nealeh, it worked (almost) 100%!

                   

                  The exported audio was already at 48kHz PCM, just like in the original captured file. For the same of conversion I used Audacity to make an MP3 out of it (256kbps, constant bitrate) and using that as the audio source instead.

                   

                  At the very end of the clip (5min) there is a noticeable delay of the audio but we're talking frames here. It can easily be corrected by offsetting the audio track.

                   

                  Thanks again to you and Steve, I had no idea about this non-AVC standard thing that Hauppauge are doing.

                  • 6. Re: Drifting out of sync audio in PE10 (h264 sources)
                    nealeh Level 5

                    Glad that sorted it out for you.

                     

                    But try using Audacity to make the .WAV - you may find it gives you a full 100% solution. It would be good to know - after all your next project may be 15minutes and those few OOS frames might become a bigger issue.

                     

                    Cheers,
                    --
                    Neale
                    Insanity is hereditary, you get it from your children

                    • 7. Re: Drifting out of sync audio in PE10 (h264 sources)
                      Ekeroil720p Level 1

                      The WAV was at 48kHz already, do you mean changing the "Advanced..." Share settings of WAV to 44.1kHz the convert it in Audacity to 48kHz?

                       

                      PS: Export in the File menu is disabled no matter what I do so I had to go via Share to get to export the audio.

                      • 8. Re: Drifting out of sync audio in PE10 (h264 sources)
                        nealeh Level 5

                        I was suggesting that you Shared the audio from PRE in its native format (whatever was in your source file) and use Audacity to convert it to 48KHz 16-bit PCM and then load that converted file in. From your response I got the impression that you converted it to MP3 and then brought the MP3 back in to PRE.

                         

                        Incidentally File> Export is only used to export Titles. All other 'exports' take place in the Share tab.

                         

                        Cheers,
                        --
                        Neale
                        Insanity is hereditary, you get it from your children

                        • 9. Re: Drifting out of sync audio in PE10 (h264 sources)
                          Ekeroil720p Level 1

                          Neale, the native format was already at 48kHz 16bit. Is it 48kHz specifically you're after or just letting PE "render" the audio itself and get rid of the issues? I'll do a WAV->WAV pass in Audacity like you suggested a bit later to see if there's a difference.

                           

                          Cheers for the clarification about the Export function, they should have renamed that to Export Title instead.

                          • 10. Re: Drifting out of sync audio in PE10 (h264 sources)
                            nealeh Level 5

                            It's the reference to MP3 that's throwing me. It is perfectly acceptable to use PRE as a file converter. And so you can Share audio from PRE as .wav then delete the audio on the timeline and import the Shared file.

                             

                             

                            1.png

                             

                            However you choose to do it I think you will get a better result with the .wav.

                             

                            Cheers,
                            --
                            Neale
                            Insanity is hereditary, you get it from your children

                            • 11. Re: Drifting out of sync audio in PE10 (h264 sources)
                              Ekeroil720p Level 1

                              Cheers, trying exactly that. Will do 2 versions, one with the re-imported WAV created with the settings above and one with a similar WAV that has passed through Audacity. Both resulting files should be identical sync wise but I'll try anyway.

                              • 12. Re: Drifting out of sync audio in PE10 (h264 sources)
                                Ekeroil720p Level 1

                                Well, that took longer than expected. I tried exporting and re-importing the WAV, giving it a pass via Audacity and finally re-using the previous MP3 I did. All the resulting vids were off sync, at a perceived rate of almost 1 second per minute, it doesn't make any sense.

                                 

                                It may have something to do with how my machine deals with AVCHD at codec level, the non standard files the Colossus creates (like Steve mentioned) or a combo of both.

                                 

                                Luckily it happens rarely and I can export the offending clips as maxed QTMOV or WMV files from Hauppauge's own software. For longer takes and important takes (family) I use a HD cam which doesn't display this issue so it's not the end of the world.

                                 

                                Thanks again for the suggestions, will research some more around this, with Hauppauge if possible.

                                • 13. Re: Drifting out of sync audio in PE10 (h264 sources)
                                  Ekeroil720p Level 1

                                  I think I solved it: by using a piece of software called VideoReDo TVSuite I transcoded the file to H.264 MP4. The whole operation took 10 seconds (when writing to the same hard drive!) and reported the image below.

                                   

                                  Opening the new .mp4 file in Premeire, it got slightly shorter: 00:05:03:28 compared to 00:05:05:39. More importantly the audio is perfectly in sync, both when previewing in Premiere and when exporting the final cut as WMV.

                                   

                                  The trial version of VideoReDo works for sub 15 minutes clips, I'll do some more tests with existing/future projects but right now it looks like the best solution.

                                   

                                  videoredo.jpg