4 Replies Latest reply on Nov 6, 2008 9:07 PM by (Let_me_think)

    audio pop or blip on clip edited in Windows Movie Maker

    Level 1
      I had a long clip that needed to have the boring parts cut out. I understand that editing frames out in PE's timeline does not really remove the cut from the avi file itself, but that's what I want--to delete cuts from my hard drive that I know I'll never need because they just take up a lot of disk space. So, I decided to edit the clip in Windows Movie Maker, then saved the movie to avi format and brought it into my timeline in PE.

      My problem is that in one of the places where I cut and closed the gap of the original clip with WMM, there is a loud POP! This pop was not heard in WMM, but is quite obvious in PE. Since it was at the end of a scene, I just edited out those 3 or 4 frames. But I'm curious as to why the pop was there.

      Also I know that the yellow line in the audio track is to adjust the volume, but I've never paid much attention to the audio track until now. Is the track supposed to have twin halves; i.e., identical wave patterns above and below the yellow line? Well, it seems odd that the wave form above the yellow line had a big blip where the loud pop was, but the wave form below the yellow line did not have it. Can anyone explain that? Is there a better solution than deleting the pop frames--next time the video frames of the pop may not be so expendable?

      Is there an easier, more foolproof way to delete unwanted frames from a clip and from the hard drive, before adding the clip to a PE project? I know PE4's Project Archive feature only saves the clips actually used in the timeline, while the Project Copy feature saves all the clips whether used in the project. or not. But I think--correct me if wrong--that the Project Archive saves the whole clip, even if only a few seconds of it are actually used in the timeline. If that is the case, I want to know an easy way to "pre-edit" and delete the long stretches of nothing happening while the camera is recording and waiting for the action to start.

      Thanks for your input.
        • 1. Re: audio pop or blip on clip edited in Windows Movie Maker
          Ozpeter Level 1
          If you imagine a sound waveform going up and down, and you edit it so that the outgoing cut is at the top of the cycle and incoming cut is at the bottom of the cycle, then at the join there will be a very sudden transition in the waveform from top to bottom, probably leading to an audible pop or click.

          When you edit audio in an audio editor, you can avoid this by cutting at zero crossings - the place where the waveform is neither high nor low, but in the middle. However, it's not so easy with video, where the video frames may dictate exactly where the cut happens. Using a very fast audio crossfade at the video edit can help by smoothing over any potential click or pop.

          That's the background - I'll leave it to others to answer the rest of your actual question!
          • 2. Re: audio pop or blip on clip edited in Windows Movie Maker
            Steve Grisetti Adobe Community Professional
            Many times this can be fixed by updating Quicktime, your audio card's firmware and, especially, your RealTek drivers.
            http://www.adobeforums.com/webx/.3c057647/2
            • 3. Re: audio pop or blip on clip edited in Windows Movie Maker
              Level 1
              Ozpeter,
              Thanks for your input. Actually, there was no audio where I cut, nor where I joined the video clips. I didn't explain the waveforms very well. The audio track 1 above the yellow line had the big waveform blip--which was the loud pop, but other than that blip, there was a flat line before the blip and after the blip. The same audio track 1, below the yellow line was also a flat line on both sides of the cut, but there was no waveform blip corresponding to the blip in the upper half of the track. I don't know why PE4's audio track is divided by the yellow line with identical waveforms above the line and below the line. (Maybe for stereo and this video is mono?) I was puzzled that the waveform blip (the audible pop) appeared only in the top half of the audio track 1 and not in the bottom half.

              Steve,
              Thank you for your suggestions. I spent half the day updating Quicktime, my Sound Blaster Audigy card's drivers, and while I was at it my NVIDIA graphics card with the latest drivers. I don't have RealTek. When I searched for firmware, I couldn't find any, but I found this post in Creative Labs forum:

              <<But why do you believe the firmware is "user" upgradable? I remember the modification of a SB Live! to SBLive! 5.1 included the step of unsoldering the chip, reprogramming it and then resoldering it. I doubt any of the Sound Blasters has a Flash memory device onboard, which can be reprogrammed without removing it from the board.>>

              I learned at Movie Maker technical support forum that I'm not the only one who gets audio blips when movie is saved as avi. So maybe it's the software. I'll use another program.
              • 4. Re: audio pop or blip on clip edited in Windows Movie Maker
                Better if you edit it in premiere elements and then save your edited portions as DVAVI and then discard orginal video to save disk space.