Audio is distorted when exporting clip

Question

Level 1

18 points

Audio is distorted when exporting clip

Hello,

I have tried many times to export a clip to a web streaming .mov file and also have tried .avi. When I listen to the original audio it is clear. When I listen to the clip it is distorted. The kind of distortion i am describing is when you record something too loud and it peaks.

I did try to lower the level of the clip in iMovie but it does not seem to have an effect at all when I export. Also, I did apply a graphic EQ wave to the file and noise reduction from the Audio FX section, and once again, the original sounds like I want it. The export is distorted. Anyone with any suggestions?

MacBook Pro, Mac OS X (10.4.10)

Posted on Nov 13, 2007 6:22 AM

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Answer 1

Nov 13, 2007 9:05 AM in response to Erly

welcome Erly to the  boards ..

hmm, hard to tell from remote..
did any other iM project before export correctly?
or is that your first project?
is this your only project which acts weird?
how do you check the audio?
in iM you hit 'play'... and the exports..? you open with...? does the app, you're using for checking the audio, playback other files correctly...?

try to check and answer all questions to locatee the problem .. sometimes, the headphone in use is just broken.. 😀

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Answer 2

Erly Author

Level 1

18 points

Nov 13, 2007 9:33 AM in response to Karsten Schlüter

Thanks Karsten,

1. This is my first project. No other project has exported correctly since I have nothing else to try!
2. I check the audio through my headphones. I have a pair of Beyer Dynamic Studio Reference Headphones. (I am a saxophone player and I do studio work) When I listen to the original project, it sounds fine. First, I split the audio off of the clip. Now a waveform appears in the TimeLine window. I applied the graphic EQ to it using the headphones to get the sound as best it could be. I then also applied a little noise reduction to the clip. Now it sounds great when I hit play in iMovie. I then select Export and web streaming for that clip. It completes it, and when I open the exported clip in QuickTime, the video looks fine but the audio is way too loud and is peaking. (This is a problem as this is a promotional video of one of my perfomances. The music is more important than the video) So I wnt back, selected the clip and pulled the audio back to 80%. Exported again and it is just as loud. I went back and reduced to down to 20%. JUST AS LOUD. I Then tried multiple export formats using expert settings, from AVI, to MPEG-4, and still the exact same thing.

What could I be missing?

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Answer 3

Erly Author

Level 1

18 points

Nov 13, 2007 1:30 PM in response to Erly

So, I kept fiddling with the clips and noticed that in my audio waveform I saw several volume lines. They were both up. The main clip was at zero but I had at least 2 volume lines in my audio waveform. I dragged one of them down, and exported and the distortion was gone! So It appeared that some way I had several waveforms overlaid on each other.

So here is what I want to find out. What is the proper way that someone would do this and not end up with several waveforms overlaid on top of each other?

1. Select a imported clip of audio and video.
2. Put a fade in and fade out audio transition on them.
3. Apply graphic equalizer to the audio
4. Apply noise reduction to the audio
5. Export as a Quicktime movie.

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Answer 4

Nov 13, 2007 10:52 PM in response to Erly

Hi Erly,

it's allways sad when a first time user experiences .. 'trouble' ..

as far as you're discribing the problem, I assume, iM does its job correctly, and we have some trouble with the QTplayer app ...

a) when you lower the volume in QTplayer (that tiny slider under the pic) .. is it just quieter but distorted, or does the distortion stop?

b) does any other audio (web, youtube, songs from your iTunes library) playback correctly, without clipping ...?

c) actually, a lil' silly, but for test purposes: would you please select a few seconds (a clip) in your iM project, Export/Quicktime/FullQuality and check the box 'selected clips only' ... create a New Project and import THAT generated file back again and hit Play.. distorted...?

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