5 Replies Latest reply on Dec 19, 2010 9:46 AM by the_wine_snob

    Audio sync problems with mpeg4 files and flv files

    tlswcid Level 1

      I use Wirecast encoder to encode and record streamed video to disk and have saved as both .flv and .mp4 files which are the two options.  I use H.264 encoding at 1080i/30 with AAC audio encoding.  I have imported the file into premiere pro and the clips have a progressive audio sync problem (where as a 2 hour game goes by the sync gets worse as we go along)  I imported through media browser and by right clicking and neither affects the outcome and have followed what was one suggestion from the help file thatI saw to import without setting the sequence settings and drag the asset to the "new" button so that the sequence is set with the same settings as the asset.  This didn't help.

       

      I saw in an old forum from 2008 with PP CS3 someone was having problems with AAC.

       

      My settings of the file from G-spot are:

       

      mp4a: MPEG-4 AAC LC

      44100Hz  128 kb/s tot , stereo (2/0)

       

       

      Any ideas, questions?  I am a relative newbie.

       

      Windows 7 Pro

      Quad core 2.8 ghz

      6 GB RAM

      NVIDIA 9200 512MB

      Updated quicktime

      Updated CS5 (Master)

        • 1. Re: Audio sync problems with mpeg4 files and flv files
          Jim_Simon Level 8

          Others may have more helpful information, but my own viewpoint is that Wirecast is used to create a finished product, not source material for editing.  You start with camera footage, edit it, (or use a live camera feed) then use Wirecast to send it out to the Internet.  You've mixed up the work flow here.

          • 2. Re: Audio sync problems with mpeg4 files and flv files
            tlswcid Level 1

            Yes, this is true.  We do live shows for the most part. and so the one or two cameras are input into Wirecast and streamed at the same time it is recorded to disk.  You are right that we could just record from the camera but this would lose some of the finished product from Wirecast.

             

            The thing about Wirecast is that it has titles and a scoreboard incorporated into the encoder as an all in one concept.  It can also act as a switcher.  We are looking at getting a switcher (probably tricaster) so that we can have an output that gets saved and one that gets streamed.

             

            This also would have a processed video file that is imported unless throughput is all NTSC.

            • 3. Re: Audio sync problems with mpeg4 files and flv files
              the_wine_snob Level 9

              Some users have had issues with AAC Audio. IIRC, the CS5.0.3 update addressed some of those. What version are you running?

               

              You might also look into ripping the Audio form those muxed files, and doing a Save_As PCM/WAV 48KHz 16-bit. Import that into the Project, and if the CTI is placed at the beginning of the Clip, with Snap turned ON, then when you drag the ripped Audio Clip onto an empty Audio Track, near the CTI, it will Snap into place. If this works, you can then either Delete the muxed Audio, or can just Mute that Audio Track. This workflow often eliminates sync issues.

               

              Good luck,

               

              Hunt

              • 4. Re: Audio sync problems with mpeg4 files and flv files
                tlswcid Level 1

                I ripped the file using adobe soundboard and, though the video is 1 hour 20 minutes long the audio track and file according to soundboard is only 37 minutes long.  Maybe I should use another program outside of adobe to rip the file?

                • 5. Re: Audio sync problems with mpeg4 files and flv files
                  the_wine_snob Level 9

                  I have found that the free audio-editing utility, Audacity, does a good job of ripping most Audio, and actually has fewer issues with some formats, than do the Adobe audio-editors. Might be worth the effort to download and install.

                   

                  Good luck,

                   

                  Hunt