Audacity Forum

I downloaded the clips off YouTube using ClipGrab. I attached a short snippet of the audio (after I exported it as an MP3) and screenshots of the file in Audacity.

I also took a screenshot of the menu when I click on the filename on the track. I have just noticed that "Left Channel" is checked, but the option is greyed out so I cannot uncheck it. However, in my headphones the audio still does come out of both the right and left.

Is there something I can do, such as "Swap Stereo Channels" or "Split Stereo Track to Mono"? When I tried this second option it creates two files. I can make one the right channel and one the left channel. Would that solve the problem?

If you know, from the extreme zoom method that the left and right sides are out of step with each other, that can be fixed.

Split Stereo Track (but leave them left and right). Select the bottom track by clicking just above MUTE. Effect > Invert. Then Make Stereo Track (from the top track). That's it. The stereo track is normal now.

You can zoom back in close to see the waves are going the same direction now, and even better don't vanish any more.

Koz

Thank you for all your help. I just wanted to verify a couple things.

1) In the attached photo is our theme music, which had no issues. I see small variations in the top and bottom stereo tracks. Is this what you are saying I should look for to make sure the audio will still be heard if someone is listening in mono ? I'm just thinking for future YouTube clips I grab, I want to be able to check and see if they will work fine without going through the process of fixing them first.

2) If I do need to fix the track I:
-Select Split Stereo Track
-Select Invert for the bottom track
-Select Make Stereo Track for the top track.
And that's all I have to do to fix the problem? And would it potentially cause any issues if I did it unnecessarily?

Thanks again!

Is this what you are saying I should look for to make sure the audio will still be heard if someone is listening in mono ?

No. That's perfectly normal in a stereo show. For example, in an orchestra, the violins will be predominantly on the left, less on the right. So during a violin passage, those two blue waves will be significantly different.

First you should be inspecting a loud passage rather than blue waves that are almost a straight line. I know what I'm looking for and I can't tell from that illustration. They're not tall enough.

In the case of a clip likely to vanish, all or most of the blue waves will be mirror images of each other. One goes up and the other goes down. Most observers would call that out of phase or "broken."

And would it potentially cause any issues if I did it unnecessarily?

Nice try. That little dance, to drop into precise English for a second, reverses in-phase and out-of-phase. If it was broken before, that will fix it. If the clip was healthy, this will break it.

So it pays richly to know ahead of time what you have. Probably the easiest way is Tracks > Stereo Track to Mono. If the clip vanishes or drops significantly, it's very probably broken. Edit > UNDO.

From 10,000 feet: The out of phase problem is pretty rare. It's terrifically difficult to get a digital system to do it by accident and there are relatively few ways to get an analog system to do it. I'll go out on a limb and say all your damaged clips are coming from the same Producer.

Run away.

If you're using the clips by permission, you might drop them a message.

Koz

Ah, great! I will just test the clips by switching the stereo track to mono in the future.

I wish the problem were more rare. It's happened on several of our podcast episodes when I have pulled show clips off of YouTube, from a variety of different YouTube users. We only use brief snippets of the TV shows we are talking about so it falls under fair use.

Perhaps it is because it is a low quality video on YouTube to begin with. But either way, from now on I will just test the clips by switching them to mono, and then go through the repair method you explained in your previous post if necessary.

Thanks for your help!

carlosross wrote: It's happened on several of our podcast episodes when I have pulled show clips off of YouTube

Could you give a link to one of the YouTube videos that had this problem. It could be useful for us to check if it is actually the video that has the problem, because if it's not, then it must be something that you are doing.

Or better still, two videos.

Koz

Never mind. H R Pufnstuf 017 Jimmy Who is YouTube posted out of phase. It sounds funny when I listen (hole in the middle effect) and the blue waves are clearly out of phase when I download it with SoundFlower.

One Sabrina Adkins is responsible for that show and a number of others. I suspect strongly just looking for that YouTube Producer would be a good guide for whether the show is damaged or not.

H R Pufnstuf 008 is damaged, too.

I wonder if she has contact information.....

I wonder if I have a YouTube account.

Koz

H R Pufnstuf In 3D - The Horse With The Golden Throat
Producer KingGhidorah58

Is OK.
Koz

We watch a different show each week so it's always a variety of different YouTube users I am pulling from. I don't quite have the ear for listening if it is out of phase on the video so I'll just have to check when I open the file in Audacity.

Thanks again for your help!