FLAC Files

[SE14man]

Hi there,

I know they say FLAC audio files are lossless but how can they be when theyre a lot smaller than WAV?
Can encoding WAV to FLAC loose quality? I can only assume not as theyre lossless right?

Also can compressing them in RAR/ZIP files loose quality in the audio file itself or is that just another way of storing it?

Am i right the only way to loose quality on FLAC/WAV is if i encode it to a lossy format such as mp3?

Thank you.

[hech54]

I've thought the same thing. FLAC, to me, would only be "lossless" if there were not different encoding "levels".

[SE14man]

Yeah exactly.. It made me wonder if it was in some way lossy..

[AlanHK]

I know they say FLAC audio files are lossless but how can they be when theyre a lot smaller than WAV?
Can encoding WAV to FLAC loose quality? I can only assume not as theyre lossless right?

Also can compressing them in RAR/ZIP files loose quality in the audio file itself or is that just another way of storing it?

All compression looks for patterns in the data and stores the patterns.
Lossy compression will simplify the data to make this easier, lossless will not.

RAR, ZIP are general file compressors that losslessly compress any kind of files. Including audio.
FLAC and APE, etc, are specialised for audio data. They are completely and perfectly reversible to wave. And they also can be streamed by media players, and include metadata.

Am i right the only way to loose quality on FLAC/WAV is if i encode it to a lossy format such as mp3?

Yes.


You can easily test this for yourself.
Compress files using these and then extract and compare with the original.

[AlanHK]

I've thought the same thing. FLAC, to me, would only be "lossless" if there were not different encoding "levels".

Wrong.
A higher level means that the analysis is deeper, takes longer, and so the compression is (marginally) better, giving a smaller file. There is no loss of data at any level.

FLAC faq

Why do the encoder settings have a big effect on the encoding time but not the decoding time?

It's hard to explain without going into the codec design, but to oversimplify, the encoder is looking for functions that approximate the signal. Higher settings make the encoder search more to find better approximations. The functions are themselves encoded in the FLAC file. Decoding only requires computing the one chosen function, and the complexity of the function is very stable. This is by design, to make decoding easier, and is one of the things that makes FLAC easy to implement in hardware.

What is the lowest bitrate (or highest compression) achievable with FLAC?

With FLAC you do not specify a bitrate like with some lossy codecs. It's more like specifying a quality with Vorbis or MPC, except with FLAC the quality is always "lossless" and the resulting bitrate is roughly proportional to the amount of information in the original signal. You cannot control the bitrate much and the result can be from around 100% of the input rate (if you are encoding noise), down to almost 0 (encoding silence).


How can I be sure FLAC is lossless?
First, FLAC is probably the only lossless compressor that has a published and comprehensive test suite. With the others you rely on the author's personal testing or the longevity of the program. But with FLAC you can download the whole test suite and run it on any version you like, or alter it to test your own data. The test suite checks every function in the API, as well as running many thousands of streams through an encode-decode-verify process, to test every nook and cranny of the system. Even on a fast machine the full test suite takes hours. The full test suite must pass on several platforms before a release is made.

Second, you can always use the -V option with flac (also supported by most GUI frontends) to verify while encoding. With this option, a decoder is run in parallel to the encoder and its output is compared against the original input. If a difference is found flac will stop with an error.

[SE14man]

Thanks for your reply there ppl!

So i could encode to FLAC form WAV then back from FLAC to WAV (using the same file) and i would get no loss of quality what so ever?

Another question i have is on mp3s... If i have a 320 mp3 and kept listening to it, would it eventually degrade in quality and end up sounding like a 128 mp3?

Cheers.

[Ai Haibara]

Thanks for your reply there ppl!

So i could encode to FLAC form WAV then back from FLAC to WAV (using the same file) and i would get no loss of quality what so ever?

As far as I'm aware, yes.

Another question i have is on mp3s... If i have a 320 mp3 and kept listening to it, would it eventually degrade in quality and end up sounding like a 128 mp3?

No. You don't alter the contents of a digital audio file just by listening to it. If you were to convert it (MP3 > MP3), yes. (You'd lose quality, but how much would depend on the encoder settings - and how long it'd take for the audio to sound like it was encoded at 128, I couldn't say. (Unless you re-encode it to 128 right from the start... ))

[hech54]

I've experimented with FLAC(FLAC Frontend) several times. The space savings between WAV and FLAC (at all levels of FLAC "compression") is minuscule at best....leaving me with a file that I cannot play in my car, or my cell phone, or my "MP3 player". Yes there are more and more portable players accepting FLAC but I personally don't own one that does accept FLAC.
And yes I've read the FLAC FAQ and Wikipedia info on FLAC and both contain many words like "approximate" and "approximation" and "roughly", etc etc etc. The balance of usefulness and space-savings is just not there for me. For the minuscule amount of saved space, I'll just leave my WAV files as they are on my computer, and if I need to listen to those WAV files "on the go" I'll use a format that is actually accepted by my car, cell phone and MP3 player.

[AlanHK]

Thanks for your reply there ppl!

So i could encode to FLAC form WAV then back from FLAC to WAV (using the same file) and i would get no loss of quality what so ever?

"Lossless" means "lossless".

Another question i have is on mp3s... If i have a 320 mp3 and kept listening to it, would it eventually degrade in quality and end up sounding like a 128 mp3?

You're joking, aren't you?

[AlanHK]

I've experimented with FLAC(FLAC Frontend) several times. The space savings between WAV and FLAC (at all levels of FLAC "compression") is minuscule at best....leaving me with a file that I cannot play in my car, or my cell phone, or my "MP3 player". Yes there are more and more portable players accepting FLAC but I personally don't own one that does accept FLAC.And yes I've read the FLAC FAQ and Wikipedia info on FLAC and both contain many words like "approximate" and "approximation" and "roughly", etc etc etc. The balance of usefulness and space-savings is just not there for me. For the minuscule amount of saved space, I'll just leave my WAV files as they are on my computer, and if I need to listen to those WAV files "on the go" I'll use a format that is actually accepted by my car, cell phone and MP3 player.

I don't care if you use it or not, I rarely do. But you are misleading people by these foolish and unfounded speculations.

No one was talking about playing on your car radio, or efficiency. Just whether it really is lossless.

And you still suggest that it isn't?


FLAC has been around for at least 8 years, if it really wasn't lossless, don't you think someone would have called them on it (aside from you, that is)?
Why don't you prove it isn't and make your name rather than just changing the subject to how you can't play it in your car.


As for space saving: some actual facts:

I took a 4:20 stereo track ripped from a CD
As WAVE: 46,021,628 bytes
As Flac level 0 encode: 34,905,681
As Flac level 8: 32,662,701 (took a little longer, shaved 2 MB)
As MP3 128 kB 7,426,144

Flac is here about 71% of wave. That was for Jazz, probably does better on simpler sources.

Basically this is an audiophile and archival format.
MP3 is good enough for me most of the time, but occasionally it's nice to know that you have a completely perfect reproduction.

Recently for instance I ripped a set of 14 CDs. As Wave, was over 7 GB. I converted them to Flac, which gave me 4 GB of files that fitted neatly on a DVD. So the "minuscule" saving was exactly what I wanted.

[hech54]

I don't care if you use it or not, I rarely do. But you are misleading people by these foolish and unfounded speculations.

No one was talking about playing on your car radio, or efficiency. Just whether it really is lossless.

And you still suggest that it isn't?

1) I wasn't talking to or referring to you. If I was...I would have quoted you.
2) Am I suggesting that the "encoding" process of FLAC is not truly, completely and utterly lossless?
Yes I am....and there is not a DAMN thing you can do about it.

[AlanHK]

I don't care if you use it or not, I rarely do. But you are misleading people by these foolish and unfounded speculations.

No one was talking about playing on your car radio, or efficiency. Just whether it really is lossless.

And you still suggest that it isn't?

1) I wasn't talking to or referring to you. If I was...I would have quoted you..

I didn't say you were talking to me.
I said you weren't referring to any question that had been asked, by anyone.
So I guess you were talking to yourself.

2) Am I suggesting that the "encoding" process of FLAC is not truly, completely and utterly lossless?
Yes I am....and there is not a DAMN thing you can do about it.

Aside from noting that you can't back up your assertion, no, I can't.
Clearly, the idea that of checking the facts before forming an opinion is foreign to your mode of thought.

[SE14man]

lol... should this really turn into an arguement fellas? I appreciate the help you guys have given me. Stick to sharing your knowledge as i
respect that! Also am thankful for all your answers.

Nice one

[t0nee1]

Originally Posted by hech54
2) Am I suggesting that the "encoding" process of FLAC is not truly, completely and utterly lossless?
Yes I am....and there is not a DAMN thing you can do about it.

Nonsense!!

Hope this helps..Think of it as therapy..

Nursery Rhymes for the Children of Audiophiles

Humpty Dumpty was fat and depressed
Until Humpty Dumpty was losslessly compressed
So all the kings codecs could algorithmically
Play back Humpty Dumpty bit-perfectly

[hech54]

Originally Posted by hech54
2) Am I suggesting that the "encoding" process of FLAC is not truly, completely and utterly lossless?
Yes I am....and there is not a DAMN thing you can do about it.

Nonsense!!

Hope this helps..Think of it as therapy

Sorry. That didn't help.
I still have my doubts that the "encoding" process of FLAC is truly, completely and utterly lossless.
....and that didn't make me stop thinking it or saying it outloud.
You're welcome to keep trying though but like I said....there is NOTHING you can do about it.

[t0nee1]

No one is trying to "make" you do anything...Hence my "hope" it helps..Some of us are just beyond help..It was worth a try!..
g-day!

[bacardi/avt]

Originally Posted by hech54
2) Am I suggesting that the "encoding" process of FLAC is not truly, completely and utterly lossless?
Yes I am....and there is not a DAMN thing you can do about it.

Nonsense!!

Hope this helps..Think of it as therapy

Sorry. That didn't help.
I still have my doubts that the "encoding" process of FLAC is truly, completely and utterly lossless.
....and that didn't make me stop thinking it or saying it outloud.
You're welcome to keep trying though but like I said....there is NOTHING you can do about it.

So what you are basically saying is that a lossless format like FLAC corrupts the data when it compress it!

Since FLAC and ZIP or RAR work on the same principle, hence the RAR and ZIP corrupts data when compressing, I strongly doubt that.

[hech54]

[So what you are basically saying is that a lossless format like FLAC corrupts the data when it compress it!

Corrupts it? I don't think I'm saying that. I am saying that when I press the "encode" button on FLAC Frontend, and I get a marginally smaller file size in return(just like I get when encoding a WAV file to an MP3 file)....well you know the rest. An MP3 file that doesn't play in anything is "corrupt"....an MP3 file that plays and functions properly has been properly "encoded" or re-encoded.
It's just very difficult for me to believe the lossless claim when words like "approximate" and "approximation" and "roughly" are used in the very FAQ written by the creator of FLAC. I don't believe a lot of what people tell me....or what I hear from others. That's just the way I am.

[XicoPT69]

@hech54

You have a very simple way of verifying if a flac file is lossless or not:

1. Compress a WAV into FLAC
2. Decompress it back into WAV
3. Compare the two waves (use "fc /b" at the windows command prompt).

If the two waves are identical, FLAC is lossless Q.E.D.