FLAC files

As far as i know compression level of 5 is standard. The higher the compression level, the smaller the size of the flac file and the longer it tales to compress/encode. compression level 0 will result in the biggest file but at highest speed. Concerning the audio quality, most say that as flac is looseless anyway you wont get a difference in sq between different compression levels. Well, i think thats subjective, from the technical side you should not get differences.... simular discussion when comparing flac to wav. I do find the wav files superior to flac, but just imho

None at all imho

Merry Christmas

Tog

+1

Thanks for the advice .

Regards

APT

Probably not, if yes then hopefully only a marginal change, and maybe the upnp server you are using can decode the flac file and send it to your streamer as a wav file.

FLAC is designed such that all the work goes in at the encode phase; it is intended to be very simple to decode, requiring only integer arithmetic. Indeed, sometimes higher compression levels can actually be quicker to decode than lower ones - checkout http://flac.sourceforge.net/ for timings. The differences in decode time between the various compression levels are pretty small. The payoff for almost all of them is cutting the network traffic by half, so whatever is at the receiving end (it could be argued) has half the work to do.

APT, in my experience it makes a HUGE difference. I originally ripped my cd collection with dbPoweramp at the default compression, then a new version came out (14?) that allowed zero compression so I gave it a try, and WOW the improvement was unmissable. Even SWMBO noticed without being told.

I then used the batch converter to uncompress my entire library and then difference is quite marked. It takes up about 30% more disk but that's no problem for me given the improvement.

they say its the extra CPU load of uncompressing the files during playback that causes the degradation in SQ. this makes sense, and for me it was a worthwhile exercise and a no-brainier.

HTH

Steve

I have found significant improvement going from ALAC to AIFF, whilst other have found something similar between compressed [allegedly lossless] FLAC versus WAV.

With HD space being such a small part of the budget, I do wonder why people continue with file types that require [allegedly] lossless decoding to produce music.

It's all bit-perfect, but some bit perfect is more equal than some other bit-perfect, as shown by actually listening to music. ... whatever is the cause ...

ATB from George

George ... Folk use FLAC because they don't want to be locked into a proprietary format, because FLAC rips are portable, because FLAC features rich, extensible tagging and because compressed rips minimise the load on a network as well as economise on storage.  imo any product that is in anyway challenged by decoding FLAC isn't working properly. Some people might wonder why people continue with streamers that can't decode FLAC indiscriminably from uncompressed WAV! And what's with the "[allegedly] lossless decoding" remark? FLAC can without any doubt be decoded losslessly. Are you alleging that your streamer can't? Name and shame!

I don't use FLAC!

I said that others have found it.

I used to use ALAC, and have found AIFF a useful improvement over ALAC.

That was on a PC. The MAC Mini is another advance and possibly would eliminate the difference in quality between ALAC replay and AIFF replay ...

I hope that helps a little.

ATB from George

Steve,

Who says so? I'd be very curious to read an article describing how CPU processing might reduce sound quality when decompressing FLAC files, as it doesn't exactly makes sense to me.

Thank you!

It depends where the decoding takes place. Use a UPNP server that transcodes from Flac to Wav as it plays to the streamer and you have the best of all worlds - level of FLAC compression would be irrelevant in this setup.

Naim do for a start; this extract taken from the Naim Label FAQ:

"*FLAC and ALAC converted to WAV are entirely lossless, however in our listening experience, the playback of ALAC and FLAC involves more complex decoding 'on the fly'. However this is not true of all playback devices."

There's also an interesting article on audiostream.com entitled "cut me some FLAC!" 

http://www.audiostream.com/content/cut-flac

I can't find any other references at the moment but, in a nutshell, the extra work that the CPU does when decompressing causes it to consume more power, and more power leads to more electrical interference - Naim know a lot about this 

In my opinion this also feeds the WAV vs FLAC debates, where people say that transcoding FLAC to WAV in the uPnP server sounds better (because it relieves the streamer from having to do the work itself, i.e. less CPU load).

So, by the same argument, decompressing FLAC is likely to bear the same improvement of transcoding whilst also giving all the advantages listed by Pev.

Steve

If the question is - is there a sound difference between compressed and lossless then IMO the answer is a clear yes. When I got my SU I ripped about 100 CDs in compressed and then did some listening tests between that and lossless and ended up reripping all of the CDs. To me it was noticeable and therefore worth reripping as I want to get it right at this stage on the basis that Ill be playing these files for the foreseeable future.

Compressed can still be lossless - that was not the question 

The question is about the compression (or not) of a lossless format. 

Ok. To be clearer, IMO non compressed FLAC is much better than compressed FLAC, how's that?

Isn't all flac, by definition, somewhat compressed?  And I don't mean lossy, I mean compressed

From Sourceforge:

FLAC stands for Free Lossless Audio Codec, an audio format similar to MP3, but lossless, meaning that audio is compressed in FLAC without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio, and you can play back compressed FLAC files in your favorite player (or your car or home stereo, see supported devices) just like you would an MP3 file.

From Wikipedia:

FLAC (<small>pron.:</small> /ˈflæk/; Free Lossless Audio Codec) is a codec (compressor-decompressor or coder-decoder) which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost. Digital audio compressed by FLAC's algorithm can typically be reduced to 50–60% of its original size, and decompressed into an identical copy of the original audio data.

Fair to say less-compressed FLAC is better than more-compressed FLAC, then?

I believe, by definition, flac can be compressed, but doesn't have to be.

My uncompressed flac files are very similar in size to wav versions of the same; the difference is the metadata that is embedded in the flac. I trust, and I am no expert, that the music element is the same in both uncompressed formats.

LILYFY, I'd completely agree with that 

Thank you for the info and the link Steve! Bookmarked for further reading! (it's a bit too late in the night/early in the morning right now )

Christian

Just to clarify - there are 2 types of processing involved in playing FLAC files -  decompressing; and then transcoding to PCM. If you leave this to the streamer/player there is a chance it may audibly degrade the sound but if you do this processing on the server and feed PCM to the player there is no logical way this can happen.  I can't see how the level of decompression could possibly make a difference if done on the server as the extra processing is trivial. If you feed any kind of FLAC to the player/streamer then doing the processing there may well affect the sound and more compressed FLAC may be worse but why would you?

Flac is open source, easily tagged  and available at numerous compression rates so if in doubt experiment with your own ears. Others prefer other codecs but IMHO the type of codec used has probably less impact than the processing and amplification stages.

Tog