Author Topic: Need help eliminating "chirping" in MP3 encoding!  (Read 3954 times)

seedpress

  • Full Member
  • **
  • Posts: 19
Need help eliminating "chirping" in MP3 encoding!
« on: December 02, 2007, 05:35:51 am »
I'm trying to prepare a bunch of prerecorded podcaasts to list on Blubrry. Unfortunately, I'm having problems with MP3 artifacts, specifically with what is called "chirping." I've heard this on other podcasts before, and found it so annoying that I actually stopped listening to the podcasts.

I'm using Audacity 1.3 with the Lame 3.96.1 "MP3" encoder. Here's the problem: If I encode at 320 kbps I get a great sounding file--no chirps. But if I encode at 64 kbps, or even 128 kbps, then I can hear really BAD chirping artifacts. (Naturally, the 320 kbps files are about 6 times the size of the 64 kbps ones.)

Now here's the BIG MYSTERY--why do Todd Cochran's Geek News Central podcasts, of which I am a big fan, sound so great, no chirping, at an encoded bit rate of only 64 kbps, whereas mine at the same bit rate sound terrible due to :o the chirping?

Should I use another encoder and ditch Lame?

Any functional tips would be greatly appreciated!

Mikethinks

  • Full Member
  • **
  • Posts: 28
Re: Need help eliminating "chirping" in MP3 encoding!
« Reply #1 on: December 03, 2007, 07:25:39 am »

Why don't you post up a few minutes of both the uncompressed wav and the mp3 at 64 and 128 and let us take a look.  There are a few possibilities, but it will be much easier to try and pin down with solid examples :-\

seedpress

  • Full Member
  • **
  • Posts: 19
Re: Need help eliminating "chirping" in MP3 encoding!
« Reply #2 on: December 04, 2007, 12:48:27 pm »
Mike,

Thanks for offering to look at some sample files; however, at the moment I don't yet have a hosting space for sample files. (Will soon, though.)

In the meantime, I've managed to MP3 encode satisfactorily at 64kbps and 128 by using WinLame, a GUI for Lame. WinLame gave me more options for encoding than Audacity does. My understanding is that WinLame uses its own, specially compiled version of the dll. But which particular Lame release WinLame was built upon, I couldn't discover. Anyway, I'm tempted to geek out on this and try to understand why Audacity's encoder doesn't work well, while WinLame's does. But I need to move forward with my project, so I'll resist that tangential geek urge--for now.

If Todd ever reads this post, it would be useful and interesting to know what encoding process and tools he uses. . . .

Seedpress