Converting formats and quality loss question

[CilyPudi]

I looked through the tutorials, but anyway, questions. For example:

If I recieve a music file in the .ape format and convert
it to .wav, then burn it, then convert to a smaller .mp3, is there any
loss in quality provided the conversions were accomplished
seamlessly?

And then, what if I reduce them to a .wma for storage to reconvert later as needed,
does all this manipulation affect the quality? I understand lossless ripping and such. I'm just speaking of converting once on my hard drive.

And finally, I've got some gigs of .mp3's I need to burn and store. Can I burn
them onto a DVD and go back and rip as needed?
If so, will the mp3's fit on the 4G DVD mb per mb, as in fit?
And could I convert all the stuff to .wma so more would fit to disc.
I've got four good burning programs. Will they burn music to a DVD
just like a CD?

CilyPudi would really appreciate this great forums advise. Thanks

[Nelson37]

Any conversion including a new compression involves loss. How much and is it acceptable is a question only you can answer. Does not matter whether the conversion is "seamless" or if it uses buttons, zippers, or Velcro. Compression equals Loss. Period.

A 4.3 Gb DVD will hold (surprise, surprise) 4.3 Gb of Mp3 files. These are accessable as data files, just as they are on the hard drive. Any DVD burning prog will burn files to a DVD. This will be a data disk, not playable as a music disk in most players.

[edDV]

Any conversion including a new compression involves loss. How much and is it acceptable is a question only you can answer. ...

And a conversion from one compressed format to another compressed format will be worse than going back to the uncompressed original. The "archive" should be uncompressed or as close to lossless compression as possible.

[CilyPudi]

Yea, thanks, that's what I needed to know. Out of curiousity, when compressing back and forth, where do the "bits and bytes" go, if that's the correct way to phrase it?

And which is considered 'best' format, FLAC or APE if EAC is used to rip both? Just wondering.

[edDV]

Yea, thanks, that's what I needed to know. Out of curiousity, when compressing back and forth, where do the "bits and bytes" go, if that's the correct way to phrase it?

And which is considered 'best' format, FLAC or APE if EAC is used to rip both? Just wondering.

A compression strategy (algorithm) extracts the most important parts of the uncompressed data and tosses the rest away. A different algorithm B might pick a different set of information from the uncompressed data. If you apply algorithm B to the results of the first algorithm it will have a much more limited set of information, thus quality suffers.

[Alex_ander]

And which is considered 'best' format, FLAC or APE if EAC is used to rip both? Just wondering.

FLAC is currently the most trusted lossless compression format for sharing audio among serious music collectors for the reason it has an option of verification during conversion process. This verification ensures that the resulting file will give bit-accurate reverse conversion. APE and SHN (Shorten) are older formats popular at their time. APE allows compressing audio encoded at higher sample rates and bit-depths than FLAC. Microsoft and Apple both have their versions of WMA Lossless and AAC (Apple Lossless) but they are not much popular and not intended for reverse conversion (very rare programs can do that).
EAC is considered to give a reliable error-correcting procedure of extracting audio and has become a standard for sharing audio extracted from unofficial audio CDs/CDRs.

[CilyPudi]

Your answers are very easy to understand and helpful! It makes sense that to "compress" something, something must be discarded to make it smaller. And different programs choose different parts to discard. So, basically you're slowly whittling away at a larger file of integrity when converting.

Never thought of it like that. Don't know much about programming. And when ripping, the best choice today probably is FLAC because of verification. Personally, I just thought APE files sounded better. But, that's probably not so.

Anyway, have a super fun safe new year!

[celtic_druid]

APE and FLAC are both lossless, so they both sound identical. Flac's popularity is probably mostly due to its compatibility compared to other lossless codecs. Basically with lossless codecs it is just a matter of features, since the sound quality in all cases will be the same (identical to the original).

You can then store the lossless files for conversion to lossy formats such as mp3 or wma for use on other devices. That way you don't waste time and where out hardware and discs reripping and don't lose quality transcoding lossy sources.

aac is not lossless by the way. That would be ALAC and there are tools for converting it. For instance libavcodec supports ALAC decoding.

For the Zune as I understand it WMA lossless files are transcoded to wma lossy.

[Alex_ander]

aac is not lossless by the way. That would be ALAC and there are tools for converting it. For instance libavcodec supports ALAC decoding.

Oh yes, ALAC is its exact name (I meant it has the same .AAC file extension being a part of their AAC specification like WMA lossless is a part of the common WM standard). I remember using a command-line utility for exact decoding audio from a torrent to wav ('ALAC decoder' designed by means of reverse engineering), other tools/codecs are intended for playback and can record to files using e.g. GraphEdit, Foobar etc. but there's no confirmation that they can exactly restore the original files like FLAC or APE do. Microsoft has a command-line tool for decoding their WMA Lossless, Apple never supplied such a tool.

[celtic_druid]

Actually ALAC isn't part of aac specs either. It is Apple's proprietary lossless codec, although from recollection it is similar to flac. MPEG-4 has ALS for lossless encoding. ALAC would have to be stored as private streams in mp4. Not sure that there are any decent tools for encoding/dealing with ALS anyway though.