9 Replies Latest reply on Dec 6, 2011 6:01 PM by Kris_24

    Strange corruption problem with AVCHD

    Kris_24 Level 1

      This problem is so weird I can't even figure out how to explain it, but here goes:

       

      I have video taken in the AVCHD file structure (puts clip into a nesting of folders, the MTS files are playable by Windows Media Player/VLC). The problem I'm having is that one of the clips has a couple seconds of corruption in the 8th minute (of an 78 min clip). Playing the clip in Windows Media Player/VLC, the clip recovers and plays just fine immediately after that point, however, in Premiere Pro CS 5.5, the audio goes into a loop for the next hour or so of footage, but then finally recovers and plays fine for the last 15 min.

       

      Why is Premiere handling the corruption so differently than the media players? Naturally, I would really like to have Premiere recognize all of the intact audio!

       

      Thanks for any suggestions/help.

       

      Kristofor

        • 1. Re: Strange corruption problem with AVCHD
          Stephen Pickering122 Level 1

          Well this isn't a reason why but should at least be a way around it.  Every now and then I will notice corrupt "blocks" in my avchd footage (almost like it was encoded at a low bitrate).  What I have to do is open it in AE and re-render it out again.  I think I might have even been able to render it right from PPro (not in the timeline but rather just rendering the clip.   I can then import it into PPro and all is well...

           

          Again, I know this isn't the same issue but if you haven't tried it already it's worth a shot.

          1 person found this helpful
          • 2. Re: Strange corruption problem with AVCHD
            Harm Millaard Level 7

            Instead of playing this clip, try razoring that 8-th minute and ripple delete it. Then try playing the timeline again.

             

            Why is Premiere handling the corruption so differently than the media players?

             

            Because it is an editor, not a player.

            • 3. Re: Strange corruption problem with AVCHD
              Kris_24 Level 1

              Well, thanks for the ideas, but unfortunately neither suggestion did anything with the problem.

               

              Can you elaborate on the difference between Premiere/After Effects reading of the audio versus the player's reading the file? Since the audio recovers immediately after the glitch when playing back the file (outside of editing applications!), I have to think that there must be some way I can recover the audio separately, but I don't know the best way to do this.

              • 4. Re: Strange corruption problem with AVCHD
                Colin-B Level 1

                Are you able to produce a section of the file (perhaps a minute in length) which shows the problem? Where the start of the file plays OK then the problem section occurs. I'm not sure what tools would allow you to chop the file up at packet boundaries, but failing all else a hex editor such as HxD would be OK. It might then be possible to take a look at the packet structure to see if there's a obvious cause.

                1 person found this helpful
                • 5. Re: Strange corruption problem with AVCHD
                  Kris_24 Level 1

                  I hope this helps you help me! Thanks

                   

                  • 6. Re: Strange corruption problem with AVCHD
                    Colin-B Level 1

                    Well that helps to see what you are seeing, but you would need to provide a section of the original MTS file to be able to see the original packet structures.

                    • 7. Re: Strange corruption problem with AVCHD
                      Kris_24 Level 1

                      How can I go about doing that/what (parts of?) files would you need to see? I'm sorry - I don't have much experience yet with working with file-based video formats...I didn't think it would be possible to take a section of an MTS file directly, but if I can, I'll certainly do that.

                       

                      Thanks,

                       

                      Kristofor

                      • 8. Re: Strange corruption problem with AVCHD
                        Colin-B Level 1

                        Your original file is obviously way too big to provide for download.

                         

                        > I didn't think it would be possible to take a section of an MTS file directly

                         

                        It's not straighforward. There may be a utility somewhere that allows you to mark in and out points, and then cuts the original MTS file into exact copies of the marked sections - but I don't know of one offhand.

                         

                        As I said earlier, you can use a hex editor to trim sections of the file before and after the section of interest, but finding the "section of interest" will be guesswork and may require a few attempts. Frankly it may not be worth the effort for you if you aren't familiar with using a hex editor.

                        • 9. Re: Strange corruption problem with AVCHD
                          Kris_24 Level 1

                          I managed to get around the problem by converting the MTS to a mpeg, taking the audio from that and keeping the video from the original. I used Free HD Converter V2.0 after trying a few other conversion programs, unsuccessfuly. I'll probably remove the program, as it's a bit on the sketchy/adware side of things, but, it did do its job, so I can't complain too much.

                           

                          Thanks for all the suggestions and help!