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Left stereo track "forgets" edits

Posted: Sat Apr 30, 2011 11:21 pm
by robotkarateman
I have a stereo track that I've imported into Audacity - imported from a WMA file. I used Audacity to delete pauses and incidental noises from the recording from that track - still linked so I've been deleting bits from both left and right channels simultaneously. I saved my project when I was done and exported to MP3 through Lame.

After uploading my file, some users reported "echoing" at points in the recording. Sure enough, there were places where it sounded like a duplicate track had been placed simultaneous to my original stereo track. This confused me because, except for a short track of music at the beginning and end, the one stereo track made up the whole of the project. But, when I went back to the original Audacity file I found that there was actually echoing when I played it back.

What I found was that a few, not all or even most, just a few, of the edits I made seemed to have been 'forgotten' by the left channel, so that there's a heartbeat of extra silence or a bit of recording that was removed from the right track. This was what was causing the echoing. But the weirdest part is that a few seconds after one of these "echoes" showed up, the tracks would suddenly pop back into sync.

Remember that this is still a single stereo track that I edited while it was merged. I never broke the channels into separate tracks when editing.

My only option now is to split the channels and go through the entire left channel to find and mute the parts where the echoing occurs. This is nuts. What happened?

Re: Left stereo track "forgets" edits

Posted: Sun May 01, 2011 12:51 am
by kozikowski
Do you have FFMpeg software installed? If it's blank look time, then that could be the problem. Audacity will sometimes open and cheerfully edit a show when it really doesn't understand what the show format is. This leads to insanity downstream when you try to use the show for a presentation.

Exactly which Audacity are you using? Help > About (I think). Audacity 1.3.11 and before had odd problems. 1.3.12 was the first 1.3 version that didn't have serious problems and we recommended it for hundreds of users. Current version is 1.3.13.

Koz

Re: Left stereo track "forgets" edits

Posted: Sun May 01, 2011 12:53 am
by kozikowski
Where did Windows Media get the file from, what kind and how long is it?

Koz

Re: Left stereo track "forgets" edits

Posted: Sun May 01, 2011 6:29 am
by robotkarateman
I was actually wrong about the original file. It came from an Olympus recorder in stereo WMA, which I coverted to MP3 in Super. I didn't have FFMPEG installed when I started the project. About halfway through, I wanted to try exporting directly to MP3, so I installed LAME for Audacity and FFMPEG for Audacity.

I'm using 1.3.12-beta under Windows 7, 64 bit.