"Skip to End" doesn't go to exact end

[Rozil]

First I'll start off by saying I love audacity and have been very happy with it for all the time I've been using it. I'm glad I didn't settle for anything else!

The problem is that when I click the "Skip to End" buttons to have to cursor pinpoint itself to the exact point when the sound stops, I instead get taken a single line too far. (By line I'm talking about how if you zoom in to the maximum, you can see little dots connected by lines. The dots can be shifted up and down with the pencil tool and the lines are what connect the dots.) I'm on windows 7 now and this thing never happened when I was using an XP computer. On XP I was using audacity 1.2.6 and now on windows 7, I have to use 1.3.12beta. The problem is a very small one and I hope it can be fixed easily. It's annoying because when cutting out part of a track and moving it to the end, I get a quick moment of silence and this makes a small pop or snapping sound because the playback goes from sound > no sound > sound again. It makes noise after a short moment of no noise so that's why the snapping happens.

At the current time, I have to zoom in to the maximum zoom, slide the cursor the left so it's pinpointed at the exact ending spot so I can then paste the sound without any cuts to silence in between music playbacks.

This was on windows 7 with audacity 1.3.12beta.
Everything worked great on XP with audacity 1.2.6

Thanks for taking the time to read about this (very minor) issue. I'd appreciate any help you can offer.

[Edgar]

You might want to grab the nightly build – 1.3.13a, the developers are making changes every day in this exact part of the code. The problem is that Audacity is not "sample level accurate" and when these values are calculated they are time-based and sometimes these time-based numbers are rounded and sometimes they are truncated and this gives rise to the problem of off-by-one at the sample level.

[kozikowski]

Yeah. It does it to me, too. Skip To End overshoots by one sample.

Picture 1.png (10 KiB) Viewed 1231 times

MacBook Pro 2.66 GHz Intel Core 2 Duo
Leopard OS-X 10.5.8
Audacity 1.3.12

Koz

[billw58]

Rozil, you can actually hear this effect? I can't. And I'm not sure Audacity is doing anything wrong.

Start Audacity 1.3.12
Generate tone, 440 Hz, 0.8, 5 seconds
Edit > Copy to put the 5 seconds on tone on the clipboard
Skip to End
Zoom into maximum
You see this:

skipToEnd01.png (18.84 KiB) Viewed 1221 times

Yes, that looks wrong.
Edit > Paste, and you get this:

skipToEnd02.png (20.33 KiB) Viewed 1221 times

If I play this back I don't hear a dropout.
Click on the split line to join the two clips and you get this:

skipToEnd03.png (20.44 KiB) Viewed 1222 times

Edit > Undo twice to undo the Join and the Paste
Click to place the cursor exactly at the end of the audio clip - at about 4.999976 seconds (?)
Edit > Paste and you get this:

skipToEnd04.png (21.31 KiB) Viewed 1221 times

Now that is not what you want! One sample has been removed from the end of the first clip.

You don't have to click on the exact end of the track. Placing the cursor anywhere past the end of the track and before 5.000000 seconds will cause this to happen.
1.3.13 shows the same results, except that placing the cursor between 4.999990 and 5.000010 will cause a correct paste to happen.

You can see the difference in behaviour between 1.3.12 and 1.3.13 by setting the selection tool bar to display hh:mm:ss+samples then click around between 4.999980 and 5.000020 seconds.

Rozil, can you describe a step-by-step procedure that produces the audible dropout?

-- Bill

[Rozil]

After using a loopable sound clip I have for testing audio and programs, I figured that there was actually no problem with audacity. Whether or not I keep the break between sounds doesn't matter. The problem I was having was that I had difficulty connected piece 1 with piece 2 and it didn't sound quite right. I zoomed in and saw this break when I pasted piece 2 and thought the problem was with the two sounds not completely connecting. After some more careful work on my mp3, I finally got it sounding right.

I just had to be more accurate when I cut pieces out of the music to rearrange them.

Thanks so much for the great detail of help you all provided. I even found audacity 1.2.13alpha to be pretty cool, but I'm sticking with the current version for now. Best of luck to development for the team!

[billw58]

After using a loopable sound clip I have for testing audio and programs, I figured that there was actually no problem with audacity.
...
I just had to be more accurate when I cut pieces out of the music to rearrange them.

I wondered if that might be it. When cutting loops it is important to cut at a point where the waveforms match up as closely as possible, otherwise you'll get a "click".

-- Bill