Is there any way to clean up Mp3s. I have a few tracks that have random "blips" in them that sound really, really horid, especially when they come out of nowhere and the stereo is turned 3/4 of the way up.

I downloaded Mp3Trim, cause i know you can check for bad frames with that, but i don't think it cleans the file, does it? Or is this just not possible?

Depends on whether the blips were in the original wave file or if they are because of a garbage data embedded in the MP3.

Since MP3Trim lets you "Save As...", you can always try it. Open it and save it as a different file name. If that fixes it, great.

If not, you have to re-rip the MP3 from its original CD and check your settings to see why you got the blips in the first place.

If you downloaded the file instead of ripping it yourself, well, then, you have discovered the reason why I don't download my music.

You can always dump it back to wav, fix the errors with Soundforge or something, and then re-encode it, but of course you lose some clarity that way. It is not that hard to find the pops and clicks and fix them (finding is usually harder than fixing), I do it all the time when I rip dirty CDs.

Of course some CDs are so bad that it isn't worth the time to do all of them. When that happened I usually got a copy some *cough* other way. Thankfully almost everything I rip nowadays are new CDs. If you are going to re-rip them I suggest Exact Audio Copy, it has ripped some CDs I thought unrippable.

You can always dump it back to wav, fix the errors with Soundforge or something, and then re-encode it, but of course you lose some clarity that way.

A week ago I would have said you were crazy for even thinking of trying something like that -- the sound quality would be so bad that you'd be hard pressed to even tell what the song used to be after all that encoding/decoding/encoding generational loss.

But last week I had someone at the radio station where I work make me a copy of a hard-to-find song that I could put into my empeg player. The song had been converted from a .WAV file to a .MP2 file to go into the radio station's archives. My program director took that MP2 file, converted it to a .WAV file, and then converted it to a 128 kbps CBR .MP3 file. So by the time it made it to my headphones, it has gone from .WAV to .MP2 to .WAV to fairly low quality .MP3. Not exactly a recipe for top notch sound quality.

At this point, I realized that my empeg player could play .MP2 files natively, so I just copied the .MP2 from the radio station archive directly into my player. Now I had both the second-generation .MP2 file and the fourth-generation .MP3. I set up a playlist with three copies of each file in it, then set the playlist to randomize, turned "info" to transient, set the playlist to repeat, and listened to it for more than an hour. (What can I say--- I like that song!)

No matter how carefully I listened I could NOT tell which of the two versions of the song was playing without hitting the mode select button on the remote to bring the transient display back up.

So... this makes me wonder if we are not being needlessly concerned about just what bit rate we use for encoding, and what version of EAC and Lame we use to rip and encode. Perhaps this MP3 format is more robust than we give it credit for being?

tanstaafl.

You're forgetting, Doug, that the MP2 you started with was very high quality to begin with. The radio station automation software uses that format because those files are so good (and they are pretty large, too, if I recall correctly).

The problems with artifacts-piling-on-artifacts is mostly a problem when you take a lower bitrate MP3 (like say, 128) and attempt to perform edits and re-encode at a low bitrate (like 128).

As with any lossy compression scheme, the higher you crank the "quality" slider, the less artifacts you notice. This is true of any generation of recompression, whether it be the first or the tenth. The lower the quality slider, and+or, the more generations, the more noticeable artifacts become.

Also, you are clouding the issue by calling the MP3 fourth generation. It's really third generation in terms of compression:

First generation: Original CD, or any properly-made digital rip of that CD in WAV format.

Second generation: The MP2 file encoded from that WAV, or any exact digital grab of the output from that MP2, such as a written-to-disk WAV of that MP2.

Third generation: The MP3 file made from that WAV.

Now, take that MP3 file and run it through a couple more generations (perhaps even only one more generation) and, depending on the material, you will hear artifacts. Being familiar with the song, it's not one of those songs where you're going to notice artifacts very soon. It's a bad test song. But there are certain songs which will show artifacts on the first 128k encode, let alone the second or third.