(sorry for my english , but I didn't find anything in italian forums..)

I've not a big HD, so I'd like to "normalize" the bitrate of my mp3 files to 160 Kbits. But there are a lot of file with a lower or identical bitrate that I don't wanna encode!

so:

if X(bitrate) is > 160 kbits then encode to 160 kbits
if X(bitrate) is <= 160 kbits then do nothing

It's absolutely necessary preserve ID3Tags

bye

Normalisation usually refers to managing the pecieved volume of a track.

So what you're after is something which would re-encode the files with a bit rate of over 160kbps and not touch lower files? I don't know of any program which does this but it wouldn't be impossible to create one for CBR files. If the files are ABR you may run into some difficulty.

Edit: It should be noted transcoding is generally considered a bad thing so if possible get the source audio and compress directly from it.

I know I loose in quality, but not so much I hope, 160 it's quite good.

Someone said to me I can do it with dbpowerAmp, but How...

Anyway, don't you think it's exagerate encote with lame 256 kbits? Some compilation I have are like that! I don't think I'll hear difference after encoding to 160, with normal PC speakers.

Why not test some files? Re-encoding introduces addional loss when compared to ripping to a low bitrate from a lossless source. So a file re-encoded to 160kbps from a higher bitrate will sound worse than a 160kbps
from a CD or lossless file.

As snaggy already said, this doesn't bother him much, so why just not answer the man?

Your transcode to 160kbps (not "normalize") can be accomplished rather easily with RazorLame.

You'll need to put a copy of LAME.EXE in the same folder as RazorLame. I'd suggest version 3.96.1.

Beware that any tags will most likely be lost in the process.

EDIT: dbpowerAmp is said to preserve the tags. I don't know about this, as I've read that it keeps version ID3v1 tags intact but not ID3v2. Also, the mp3 encoder is no longer free, although it does have a free 30 day trial.

My bad. I was assuming he knew only of the loss caused by using a lower bitrate, rather than that and the extra loss added from transcoding.

With foobar2000, you can do like this:
* Add all your mp3's into foobar's playlist
* Sort your playlist in descending bitrate. Select the files with bitrate > 160.
They are in the beginning of the playlist (right-click/properties to see bitrate)
* With a full install of foobar ("special" download) you can re-encode to desired bitrate (you need Lame for this).

Thanks everybody, i did it with dbpowerAmp and DBpowerAmp media library, sorting files by bitrate, a good idea Larswes, but I think i won't reencode (how do you say that, "transcode again"?) becouse besides loosing quality, it takes to me too much time!

bye

As I understand it, anytime you try to change the bitrate of an mp3 file what is actually happening is that the file is being decoded to wav and then reencoded at your chosen bitrate, so you are taking 2 quality hits, first from the lower bitrate, and second from the fact that you have done 2 mp3 encodes on the file. It may not be apparent from the particular program you are using that this is what is happening, but it is. Simply stripping, or peeling bits without reencoding, is not possible on an mp3 file. Even on the codecs for which it is theoretically possible, such as vorbis, it has never been implemented very well.

See this thread for more information

http://www.hydrogenaudio.org/forums/index....showtopic=32379

Here's an MP3 repacker.

I just wanted to make sure I am clear on this, since I was browsing for a thread something like this one.

If you alter the bitrate on your mp3s it will cause them to deteriorate to a degree?

I came looking because some of the mp3s I have are at various bitrates; 160/192/256(if I am correct on this one) and I was curious if there was anything to be gained by having them at a set rate. When I rip them myself I always do at 192 and was thinking of using my dBpowerAmp to change the others to 192. Now I am not so sure

Any clarification would be appreciated.

TIA

If you try to change the bitrate on an mp3 file what you are doing is decoding it to a wav file and then reencoding it to mp3 at whatever bitrate. This is a lossy process and will further degrade the file. There is absolutely no reason at all to raise the bitrate from 160 to 192.

I don't see any benefit from having them all at the same bitrate.

Totally agreed. Also, there's little reason to lower the bitrate from 256kbps to 192kbps - assuming the reason you rip to 192kbps because you're happy with the quality, then you might not be happy with 192kbps encoded from 256kbps - it'll be lower quality than all your 192kbps direct rips.



No, none at all. Just leave them as they are.

If it was a space issue, that's different, but RocknRoland mentioned increasing the bitrate of 160kbps files, so we're not trying to save space here.

Don't let some idea of having a "tidy" collection make you wreck the quality of your audio files and waste space too!

Cheers,
David.

EDIT: of course, since we're talking about tracks that you already legally own, then you can re-rip from the original CDs. CDs are useful like that. They're great. Get some.

Gotcha. I will leave eveything alone. One comment brought up another question with me then, should I rip at the highest bitrate possible then?

For the life of me I cannot recall where I came accross to have them at 192 but I know I did and that was why I have remained at that rate.

One other question, since I do create my own "best ofs" eventually they will end up on disk. If, say I make a disk then later down the road take some of the songs from it to have on my pc, has that degraded the quality as well?