4 Replies Latest reply: Mar 12, 2013 9:09 PM by Guy Burns RSS

    Incorporating external sound within a clip without re-encoding

    Guy Burns Community Member

      I'm hoping someone more knowledgeable than me can save me a bit of time. If Premiere is not capable of doing certain things (see below) then I won't have to vainly search through the manual to find how to do them.


      1. Can Premiere automatically align a sound clip that was taken with an external recorder, to the sound already inside an AVCHD clip? A TV cameraman I was talking to recently said that FCP can do it. For a particular clip, he just highlights a series of sound files (if I understood him correctly) and FCP chooses the right one and aligns it to the existing sound.


      2. Can I import a clip in AVCHD format (taken on a GH2), remove the existing sound track and replace it with another (for example, as above), and save again as AVCHD, without the video part being re-encoded? What I want to do is store the externally recorded sound files within the clip instead of having them as separate files. Simplify my archives.


      I don't need instructions how to do the above, I just want to know if it is possible, and what technical terms to look for in the manual.

        • 1. Re: Incorporating external sound within a clip without re-encoding
          J. Simon Community Member

          1. might be possible if both clips have identical timecode.


          2 can't be done with any software that I know of.

          • 2. Re: Incorporating external sound within a clip without re-encoding
            Dave Merchant ACP/MVPs

            (2) is possible because AVCHD is effectively the same format used on Blu-Ray discs, but it's a little fiddly. There are several third-party demultiplexer (demux) applications available which can separate the elementary streams from the MTS file on an AVCHD media card and give you the H.264 video and AC3/PCM audio streams as separate files, and matching multiplexer apps that will stitch the streams back together again without altering their internal data. If you can create a replacement for your audio stream which exactly matches the original in bitrate/length/timing then it should work just fine, but it's hardly a one-click workflow.


            As this isn't anything to do with Adobe software and these apps are used to extract copyrighted material from Blu-Ray discs I'm not going to give links - but Google for 'AVCHD demux' and you'll find things to try.

            • 3. Re: Incorporating external sound within a clip without re-encoding
              Jim Curtis Community Member

              Look into a third party application called PluralEyes.  FCPX has this function built-in, FCP7 does not.

              • 4. Re: Incorporating external sound within a clip without re-encoding
                Guy Burns Community Member

                Thanks for the responses, but I'm still not clear about what is and is not possible. I've got the full Adobe suite, so if any of the software included in the suite can automatically sync sound, please let me know.


                1. Jim Simon responded that it might be possible to sync sound if both clips have identical timecode. Well, my recorded sound does not have timecodes, so does that preclude Premiere from automatically syncing external sound to internal AVCHD sound?


                2. Dave Merchant suggests third-party software for (2), the demuxing/remuxing. That's sort of okay, but I'd rather stick with Premiere (if possible) or FCPX (if I have to). So, does Dave's answer mean that Premiere is not able to replace sound inside an AVCHD clip without re-encoding the video when saved?


                3. Jim Curtis suggested PluralEyes. Looks good for automatic syncing. But it means another piece of software, and for $100 extra I can buy FCPX. He also says that FCPX has this function built in (I assume he means auto sound syncing).


                I'm left with this (correct me if I'm wrong):


                A: FCPX and PluralEyes can automatically align sound files. Premiere cannot.


                B: FCPX and Premiere cannot, without re-encoding when saved, align and replace the audio in an AVCHD clip. For that I need other software.