I have an hour-long podcast in mp3 format composed of three contiguous presentations (48 min, 12 min, 2 min) to the tune of 58MB. The only part I really want to keep is the 12-min segment.

I have no idea how to edit the item so that that I can extract the item and/or erase the other items. I don't even know if such is possible within iTunes, where the podcast is stored (in the Library) — The Missing Manual is silent on such — and that's the only app that I have that might be able to do the job.

Directions?

Mac OS X 10.7.5, iTunes 10.7

Edit: I note that it might be possible to edit podcasts via GarageBand, but all the references point to tutorials for doing so. I'm not interested in long drawn-out protocols for doing such editing; I just want to get the job done in a finite amount of time and then forget about it.

You might try the free audio editor Audacity. The interface is somewhat like a cut and paste of an audio wave/signal using sliders. Find the 12 minute interval you want and Cut and Paste to a new document, then Save.

Alternatively you could Cut the 48 and 2 minute segments, then save what is left.

Oh, and to get the podcast into Audacity, choose File>Import and go to ~/Music/iTunes/iTunesMusic/Podcasts.

This probably all sounds worse than it really is.

Thanks. Audacity appears to be a nifty, fairly comprehensive app, but unfortunately way too complicated (or confusing) for me to use. It sure isn't a simple "cut-and-paste" procedure.
I can open the podcast, isolate regions of it, but cannot manipulate by any means the parts I've isolated (in spite of attempting to follow the accompanying manual's instructions). So essentially what I've got is an mp3 player with a wave form that I can gaze at.
C'est la vie.

EDIT:
Reading further through Audacity's notes, I find that I would need to download and install the optional LAME MP3 encoder in order to export the "Audacity project" as an mp3 file (even though the podcast is already in mp3 format).

So it really is more complicated and convoluted that it was touted to be.

Back to square one.

Aside: Reading the 50th anniversary edition of Thomas Kuhn's The Structure of Scientific Revolutions is a cakewalk compared with Audacity's manual.

Despite being a little complicated to use, (and in your case, also requiring the lame codec download) I would still recommend it. I'm not any kind of expect at audio editing and I use it from time to time to do audio editing. (most recently to make new ringtones for my iPhone)

Out of curiosity, I took a look at Audacity.

1. I first copied my file, an .m4a/Apple Lossless, so I could work with the dupe.
2. I selected "1 (Mono) Recording Channel" from the top control bar, but that's the only change I made to the interface
3. I opened the dupe (command-O > Select).
4. Using the time stamp at the top of the window and my space bar to start/stop play I located the section I wanted to save.
5. I command-click dragged from its start to the start of the piece, i.e. highlighted the section to be deleted, and hit "delete".
6. I repeated that procedure from the end of my selection and was left with what I wanted.
7. I hit Audacity > File > Export Audio and selected "AIFF (Apple) signed 16-bit PCM" from the "Format" drop-down.
8. I hit save.
9. Bingo!!!

The resulting file played in iTunes with no further ado.

Bottom line is you dropped out of the game without trying any other formats when you couldn't export your podcast as an .mp3.

Note: I used a music .m4a in the absence of any .mp3s.

Note 2: Since AIFF is a lossless format, the file is almost twice as big as my original.

Note 3: Is it odd that when I saved my file as a .wav, a Windows format, it played in iTunes all the same, although at a slightly reduced volume?

I glad you could make Audacity do your bidding.
I couldn't, as noted in Post #37011. (And I'm not willing to spend considerably more time than the entire podcast to figure out how to make Audacity work for me. This is purely a one-off issue. Perhaps when I haven't got anything better to do ....)

The entire project took less than 15 minutes (and following my instructions should take you even less time), and it was dead easy! I never even had to refer to "Help", because what you want to do is pretty intuitive.

I'll just add step 4a: I forgot to check, but you may be able to expand the time bar into smaller increments by hovering your cursor over the waveform and side-scrolling.

That's what I would have thought too, but for me essentially nothing worked (and I spent an hour trying to make it work).
What you did doesn't apply to what I want to do.
I appreciate the encouragement, but I'm not wasting any more time on the project.

What I did is precisely what you want to do!

I saved a segment from the middle of an audio file (Edit: albeit in a different, although equally playable, format).

But...nuff said. :shrug:

I wanted the exact same file format (mp3) as the original, which would also require yet another download/installation (LAME MP3 encoder).
Since my 'intuition' can't make it work, I could chalk it up to early signs of a failing mind .... {sigh} Let's go with that.

OK, but please teach me something.

> "I wanted the exact same file format (mp3) as the original...."

Other than file size, what's the difference between saving your podcast in one format or another?

File size and format; every entry in my iTunes library is in mp3 format, and that's simply the way I want it.

As I pointed out in my attempt to use Audacity to edit, I supposedly did more or less exactly what you did, but in my case nothing worked: Highlighted a chunk, tried to delete it: nada.
No matter what I did or however many tries I made, same result.

When I look at the tableau produced by Audacity, it is visually overwhelming, stuffed with so many entities, most of which are unknown to me, that my mind just goes "fuzz" — and that's ballgame for me. The whole thing is just tortune since I just don't have the technical background to make sense of it all — and I am unwilling to devote the time and energy to get around this block at the moment.

So, unless there's an app out there that doesn't require me to have an advanced engineering degree to reach the desired conclusion, this issue is dead in the water.

EDIT
Just to frame the situation a bit more broadly: I see and use the computer strictly as a tool — Internet access, written document production, storage device, and the like. More than 50% of the apps which came with Mac OS X Lion I have no use for and have never examined. Even third-party apps which I use all the time I probably only use 5% of their capacity: Office for Mac mostly Word – I have touched any other component in years; Photoshop I use now and again, but I can use Preview for most of my JPEG diddling and its use is definitely intuitively straightforward; and so forth.

When my computer tries to use me as a tool or to force me to do its bidding through (to my mind) poorly designed apps or apps directed to a more technologically minded user who already knows what's going on, I draw the line.
Ergo my attitude in this thread.

If you've got a Dropbox, or some other place online to post the mp3 file, I can edit it for you.

Many thanks for the offer, but I don't (and most likely won't – until such service becomes impregnable – I don't entrust anything to the Cloud – and Dropbox's history is sketchy – if Edward Snowden was leery of it and called it "hostile to privacy", who am I to gainsay him).

I've got no love for the cloud either, but why turn your back on its usefulness for passing public domain and other innocuous material back and forth?

Long term storage being unnecessary in instances such as the present one, it would be no more than a temporary "atmospheric" clipboard.

Non-secure encryption keys and many other paranoid reasons. Allow a crack in the wall and it will most certainly expand.

so gt out disk utility and make a 100mb image with encryption. Put your data on that, and put the image in the cloud. Who cares who has access to the DMG? Only you have the key. (and whomever you give it to)

I use this approach with my SSH keys since I use pubic key login all the time. Your SSH keys are in a hidden folder in your home, with NO protection on them at all unless you are using filevalut. (which I do not) So when I login, a script mounts a little DMG from my home folder, using a key from my keychain (which my login pw unlocked). If my computer is stolen, they won't see my .ssh folder if they sled up my hdd. And if they reset my password and login as me, my DMG keychain won't unlock so my DMG won't mount.

Just because the channel is insecure doesn't mean you can't secure it and use it securely anyway.

Many thanks for the encouragement (yet again). I appreciate your efforts (and even cajoling).

Apparently I haven't made my insecurity and incompetence in such matters obvious enough. What you describe, at least for the moment, is well beyond my ken.

As for the original issue, I intend to give that another shot (with Audacity) somewhere down the road when more pressing matters don't intervene. (And to that end I've even/already downloaded/installed LAME MP3 encoder into the Library.)

Encore une fois: merci – à toi et à tous.

I've been meaning to post this, and now's a good time...

In case you're unaware of it, mp3 is a "lossy" compressed format, meaning that part of the audio content (I believe it's the top and bottom of the wave.) is lost during compression.

If your podcast is an mp3 it's already undergone this process, AND if you edit and save it as an mp3 it will undergo it AGAIN.

So be aware that your starting audio quality is going to degrade, the best thing you can do being to save your mp3 at a high(er) bps rate so you'll lose "less more". (This is a far more important issue when you're dealing with music, classical music in particular.)

Edit: If you run into a sound quality issue, saving to a lossless format (Apple Lossless [m4a] generates the smallest files of its ilk.) is a good idea.

though the true audiophiles all demand FLAC

You might be interested in this:
http://www.theregister.co.uk/2015/11/12/snowden_guide_to_practical_privacy/