what the differents from mp3 files flac files

From a discussion on another forum:

I'm late to the discussion, but I think I was referenced above, and I have a couple of cents' worth I can put in. mp3s and .wma and other lossy formats have a place. They're for people who want to listen to music on a portable player in earbuds, so overall sound quality isn't an issue; the issue is mass storage of tracks in the smallest number of megabytes. It isn't a true high-fidelity medium.

Think about how voices used to sound on telephones before the cell phone was introduced. They were perfectly clear for the limited audio spectrum they took up. When the cell phone specs were being drawn up, a codec was invented that works similar to mp3, whereby the sound is digitized and downsampled to the absolute lowest bitrate they could get away with. Unfortunately, this is just on the other side of intelligible... it's crappy but it works. Cell phone calls could sound much better if they'd increase the bitrate, but it could never sound as good as the best analog phone unless they increased it to such a high rate that it would take up too much bandwidth on their system. So we're stuck with it.

A lot of science went into the creation of the mp3 standard. It was decided what frequencies they could lose and still have your brain recognize it as music. 128 kbps was decided as the line under which too much quality was lost. The total of 128 is reached by adding the 64 kbps of each channel, the same as how the CD standard sampling rate is 44,100 Hz stereo, but each channel only has 22,050 Hz of information. Resaving a 128k mp3 at a higher bitrate like 192 or 256 or 320 doesn't make it sound any better: it removes more information from it and makes the filesize bigger. If you're in an audio editor and you do something with a 128k mp3 and resave it at 128, it halves the bitrate it was at before, so that what you have now says that it's still 128, but in reality is 64 kbps, or 32 kbps in each channel. This is approaching cell phone quality.

In a 128k stereo mp3, the file size is reduced even more if *joint stereo* is selected, which alters the stereo separation and makes it worse. The spectral view of an average mp3 shows that there is nothing above 16,000 Hz. The sound below that has had several bands of frequencies removed, resulting in what looks like Swiss-cheese holes in the audio spectrum. This is what makes cymbal washes and hi-hats sound all warbly, and why overall the music sounds weak and anemic. Somebody decided that you didn't need to hear those frequencies. One anomaly of the mp3 format is that of file padding. I don't know the reason why, but it is impossible to split a continuous recording into tracks in mp3 without having a gap at the end of each one. This makes it unsuitable for concert recordings.

A stereo .wav file takes up approximately 11 MB of space per minute. So a 3:00 song is about 30 MB. A 128k mp3 of the same song takes up about 3 MB, because so much information has been removed from it, to make the filesize smaller. This is why mp3 cannot be taken seriously as an archival format. Its whole purpose is to wreck music to make it smaller so you can have thousands of them on your iPod. Now, obviously, the higher the bitrate, the better the sound. But even at 320, information is still being removed. Once it is removed, you can never get it back. Transcoding an mp3 back to .wav or .flac does not make it lossless. It preserves it in whatever kind of reduced quality it was in as an mp3, but now it takes up more space.

FLAC is not an audio format. It is an algorithm by which the physical size of .wav files is reduced without any information being removed. It's like WinRAR for sound files. If you extracted a song off a CD and converted it to .wav and then to FLAC, you would be hearing the same thing as if you were playing the CD. If you decoded that FLAC file back to .wav, it would be bit-for-bit identical to the .wav that made it. Stereo FLAC files at level 8 (highest compresion) are on average about 60% the size of a .wav file. Mono (one-channel) files are even smaller with no loss.

Just going by discussions I've read over the years in places where there are sound files, not many people are very well-versed in this subject. "But I can't tell the difference!" That doesn't matter. Maybe *you* can't hear it, but that doesn't mean that an mp3 doesn't contain a permanently damaged version of the audio you're listening to. It's OK for portability, but it really has no place in the world of rare and archival recordings. The objective there should be to preserve them in the highest quality forever. This being said, upsampling a CD format recording in 16-bit 44.1 KHz to 24-bit 96 KHz does not improve the sound, it just makes the filesize bigger. If you want 24/96, the source audio has to be recorded in that format.

I make no apologies for being picky about the sound files I collect. I do have some mp3s, and they are segregated into their own directory so they don't get mixed in with the rest of my lossless files. I only have them because the audio seems to be unavailable in lossless, even though there is *somebody* out there who has it in lossless: the person who encoded it. I have passed on tons of stuff that I might have liked to hear, because it was lossy. While I appreciate the effort that people go to, to share rarities, if they're mp3s, I don't download them. I'll wait for the real thing to come along, or I guess I'll always go without it. What is a hassle, is that now it is necessary to open up everything I get and look at it in spectral view to make sure that it isn't an mp3 transcoded to FLAC. I wouldn't want to be passing that kind of thing around, because, as mentioned, it dilutes the trading pool. Archival material deserves to be preserved in an archival format, and nothing less.

Well, maybe that was more than two cents' worth, but I hope it makes sense to you.

Friends don't let friends use .mp3.

thank you all

correct;
Now it is necessary to open up everything I have or get and look at it in spectral view to make sure that it isn't an mp3 transcoded to FLAC.
Some lossy items I share will be marked as such.
However: Most of my uploads to Stonesvault and shared here are not checked because I did not know how to check but now and than I am working on that.