[dazzer1975]

Ok, this has been done to death, but I am about to re-rip my entire cd library and would like to know a few things.

In the past I have used eac to rip into wav, although before head-fi I sued any program to hand to rip into any bitrate, hence the re-ripping of my library now.

I understand flac is compressed but lossless, forget the issues of player compatibility, every player I have at present can support flac (barring the 6th gen classic ipod as it doesn't have rockbox, but as I use that predominantly for tv series, podcasts and movies it isn't that much of an issue) I am struggling to understand how compression can be a good thing other than for space saving. I mean how does flac compress exactly while retaining all the information in the audio file?

Basically, I usually use wav, and feel in the safe zone with wav knowing its lossless and the file sizes confirm that lol

but am looking for reasons to use flac.

This is where you guys come in.

Storage space is not an issue on my pc, I could store my entire library three or four times over in wav, so which do you use and what are the reasons for that choice?

 

[iriverdude]

It's like winrar, winzip. When you compress a excel document with winrar, then uncompress it, is your spreadsheet corrupt? Nope.

Use flac.

 

[null_pointer_us]

Quote:

Originally Posted by dazzer1975 /img/forum/go_quote.gif I mean how does flac compress exactly while retaining all the information in the audio file?

Computers store digital data (files) as a sequence of bits. A bit is a binary digit, which can have only two values: 1 and 0. Lossless compression software basically analyzes bit patterns for their length and frequency (in the file). The compression software replaces long bit patterns occurring numerously in the same file with much shorter bit patterns; conversely, shorter bit patterns occurring infrequently in that file are replaced with longer bit patterns.

For example, if you've got the 8-bit pattern "00000000" occurring in 247 places in your file, the compression software might encode all 247 occurrences of that pattern as one randomly-chosen 2-bit value "10." In this example, the encoded values would take 1/4 the space of the original values. The trick is, of course, that some information about this substitution process must also be stored within the file so that the information is not "lost."

The actions of the compressor are added to a substitution table that ultimately gets stored in the compressed file's header so that the decompression software knows which codes stand for the real bit patterns. This way, the decompressor can read the substitution table, determine which codes correspond to the original bits, and restore the original file in a bit-perfect manner.

The caveat to lossless compression is that, in its compressed state, the data is no longer audio data but actually just an encoded database of bit patterns that makes sense only to the compression/decompression software, so your audio player has to specifically support the decoding rules (e.g. FLAC, AAC) to convert the data back into its original, uncompressed state on-the-fly (during playback).

The reason for using FLAC, compared to a generic lossless compression format like ZIP, or a disk-wide lossless compression format like a compressed filesystem, is that FLAC is optimized to work with certain types of data, which means its compression/decompression rules are potentially more efficient and convenient for these types of data.

 

[gregorio]

Although in reality it's a bit more complicated, think of it like this:

Let's say in a quiet one second section of music the most significant bit (MSB) is set to zero for the entire second. In a CD format wav file you would have 44,100 instances of this bit = 0. So what you could do is have a small mathematical equation something like "MSB = 0 x 44,100". I've got no idea of the actual equations used but you can see that storing this equation is just going to need a few bits of data rather than the 44,100 bits of data in the original wav file. Providing you have a decoder which can understand the equations and calculate them back to the original 44,100 zeros you are going to get total precision with a smaller file size.

Hope this makes sense. I'm sure there are others around here who could explain lossless compression much more accurately and simply.

EDIT: Damn, someone has just explained it far better while I was writing my post. See the previous post to mine.

G

 

[krmathis]

Apart from the audio data compression, as explained above, FLAC have features not present in WAV.
Especially usable are the support for metadata (tags) and album art. But also the fact that it has checksums embed into it, so you can easily verify if the files are 100% intact. Smaller files can also be a benefit when backing up, since there are less data transfer and less storage space needed.

 

[dazzer1975]

wow fantastic information.

Looks like I am going to re-rip everything into flac. I know it's sad but I'm looking forward to it lol

And many thanks for the detailed explanation as to how lossless compression works, put my mind at ease a bit that has.

Cheers guys.

 

[iriverdude]

If you've got wav's you don't need to re-rip, unless your ripper didn't save .cue information. You'll soon know if you use converter, drag a wav album across. If it shows untitled for everything no .cue info was saved. I'd wipe your wav's at this point going back to your CD's.

I recommend EAC. It comes with flac but not the latest version. I would also recommend replaygain scanning your albums, use foobar for that. Album Art agregator for covers. Bit long winded using three applications, rather than just one. But probably best for rips/encodes.

 

[dazzer1975]

I do have wavs, but they are all lost in the abyss that is itunes which has conveniently given me literally 7 copies of some albums, ripped apart other albums if a guest artist is featured etc etc so its a complete wipe of what I have barring non audio files and a re-rip into a lossless format, and I have been convinced to try flac.

Presumably I could convert into wav from flac if the need/desire arose?

I have eac, and have been looking at different add-ons which would deal with flac so its great to see your recommendations for a good solid rip/encode.

so I need foobar and then album art agregator for the covers etc. cool appreciate that info.

 

[Acix]

I don't see any point to use flac or mp3 if you have wav file's...

 

[dazzer1975]

i have a mixture as detailed in the first post, and furthermore, the library I do have is far from organised. It would take longer to go through it manually and correct it and re-rip into wav what needs to be re-ripped into wav (or flac) than it would to just start again with an organised file tree of freshly ripped cd's in the the chosen lossless format.

 

[iriverdude]

Del *.* /s
then start again ripping to flac.

 

[dazzer1975]

lol you got it

 

[Ham Sandwich]

FLAC has embedded tags and WAV does not. If you properly tag your files they are much much easier to manage. You can move them from one media player to another and the tagging info goes with them. A library of all properly tagged files with embedded cover art is oh so more convenient.

There are also tools that can rename and reorganize files based on tag info. So if you have your directory tree organized by artist and you later decide you'd like to do it based on genre it is easy as long as the files are properly tagged. J. River Media Center, MediaMonkey, MP3tag (it does FLAC as well), and others can all do that.

 

[Fryguy8]

Quote:

Originally Posted by Acix /img/forum/go_quote.gif I don't see any point to use flac or mp3 if you have wav file's...

Flac consumes less hard drive space and provides the ability to store metadata about the file in the form of vorbis comments.

 

[Acix]

Quote:

Originally Posted by Fryguy8 /img/forum/go_quote.gif Flac consumes less hard drive space and provides the ability to store metadata about the file in the form of vorbis comments.

Well...Flac consume your audio quality too.