HydrogenAudio

Lossless Audio Compression => FLAC => Topic started by: sgold on 2012-07-17 16:19:44

Poll
Question: FLAC
Option 1: -0 votes: 2
Option 2: -1 votes: 0
Option 3: -2 votes: 0
Option 4: -3 votes: 0
Option 5: -4 votes: 1
Option 6: -5 votes: 48
Option 7: -6 votes: 10
Option 8: -7 votes: 1
Option 9: -8 votes: 99
Title: What FLAC compression level are people using these days?
Post by: sgold on 2012-07-17 16:19:44
I’m about to re-rip a fair amount of CDs and am thinking of upping the compression level to -8 from my usual -5.

Before I do this I’ve been reading some generally quite old forum posts and occasionally coming across contra-indications for switching to -8

Largely, the few negatives I’ve seen seem to be around compatibility issues and extra time to decode -8 on playback, neither of which I would imagine are relevant with today’s technology?

Before I make a decision on this has anybody experienced or is aware of any negative compatibility or functional deficits of -8 what-so-ever for example across different media players and devices or indeed native to the compression level itself over a lower level of compression?..I'm not talking about sound quality which of course is the same at any level of compression or the time it takes to compress the file. Rather I’m referring to the pure universal functionality and reliability of -8 vs any lower level. What are people mainly compressing at these days? Have folks shifted up the compression to -8 as technology has improved or do some people feel they have more peace of mind at a lower level for whatever reason?
Title: What FLAC compression level are people using these days?
Post by: Blueshirt on 2012-07-17 16:39:11
What are people mainly compressing at these days? Have folks shifted up the compression to -8 as technology has improved or do some people feel they have more peace of mind at a lower level for whatever reason?

I can only speak for myself, but I have always used -5  compression for my CD rips to FLAC and I see no reason to change it now. I certainly wouldn't re-rip a load of my CDs to -8 compression just because technology has improved! There is nothing wrong with my FLAC files that were compressed at level -5, and it is all going to sound the same anyway. So for me, it if ain't broke don't fix it!
Title: What FLAC compression level are people using these days?
Post by: Soap on 2012-07-17 16:42:05
I certainly wouldn't re-rip a load of my CDs to -8 compression just because technology has improved! There is nothing wrong with my FLAC files that were compressed at level -5, and it is all going to sound the same anyway.

Nobody in their right mind would rerip to get -8 FLACs when they have -5 FLACs, they would transcode.

I think we can safely assume the reripping is because OP either didn't do it securely the first time or only ripped to lossy.
Title: What FLAC compression level are people using these days?
Post by: eahm on 2012-07-17 16:59:45
-6, best one in my opinion for speed/ratio/performance.
Title: What FLAC compression level are people using these days?
Post by: sgold on 2012-07-17 17:01:15
Yes. The CDs i'm re-ripping were amongst the very first i did years ago and with the benefit of hindsight and the cruelty of an obsessive-compulsive mind    could have been done more elegantly in terms of set-up, etc. The motivation to re-rip is nothing to do with the compression rate however.
Title: What FLAC compression level are people using these days?
Post by: Porcus on 2012-07-17 17:36:45
Nothing but -8 here. And right now my drives are 98 percent full. Wouldn't have made it in -0, that's for sure.

Then, I guess it depends on whether your ripping application converts while ripping. dBpoweramp (my choice) is track-oriented, so it encodes a track while reading the next one. That effectively means that I only have to wait for encoding the last track of each CD, except every now and then when long and short tracks alternate. This on a laptop with a Turion TL56 @ 1800 MHz. If your application first rips the entire album as one image and then converts, then I would probably have ripped to -0 and then reencoded to -8 over night.


(OK, I did automated ripping with a changer, but -8 is still how I do it when I have brought a handful of CDs home.)
Title: What FLAC compression level are people using these days?
Post by: Frank Bicking on 2012-07-17 18:00:04
Poll added. Let's see if there are any differences to 2007-2009 (http://www.hydrogenaudio.org/forums/index.php?showtopic=58731).
Title: What FLAC compression level are people using these days?
Post by: sgold on 2012-07-17 18:24:28
Nice! Many thanks Frank

Personally, my very subjective instinct is that the -5/-6 region just feels safe and robust in every aspect, that's purely psychological i'm sure; but i'm getting the feeling that recently -8 is being increasingly adopted?
Title: What FLAC compression level are people using these days?
Post by: pawelq on 2012-07-17 18:43:27
-7. Don't realy know why I chose it. And I have no intention to change, I guess that converting using more aggressive compression would yield a minute benefit.
Title: What FLAC compression level are people using these days?
Post by: skamp on 2012-07-17 18:46:15
I ran a benchmark on over 5,000 FLACs and determined the overall gain in disk space of FLAC -8 over FLAC -5 to be exactly 485 MiB for a total of 134 GiB. That's 0.35%, folks. IMO, it's only worth it in situations where the increased encoding time is absorbed by some other task running in parallel, like ripping a CD. Worth transcoding your old FLACs? Total waste of time and electricity.
Title: What FLAC compression level are people using these days?
Post by: AliceWonder on 2012-07-17 18:50:21
I use -8 but I use flac for archival, I don't listen to them, so I figure compress them as much as I can.
Title: What FLAC compression level are people using these days?
Post by: db1989 on 2012-07-17 19:06:00
Personally, my very subjective instinct is that the -5/-6 region just feels safe and robust in every aspect, that's purely psychological i'm sure
afe” and “robust” imply what? Superiority of support among players, error resilience, or some other unknown thing? You will need to define your terms before your statement can have any meaning. Which is not to imply that any such differences exist: I highly doubt it.
Title: What FLAC compression level are people using these days?
Post by: Porcus on 2012-07-17 19:32:24
I ran a benchmark on over 5,000 FLACs and determined the overall gain in disk space of FLAC -8 over FLAC -5 to be exactly 485 MiB for a total of 134 GiB.


That's very close to  Synthetic Soul's comparison http://synthetic-soul.co.uk/comparison/lossless/index.asp (http://synthetic-soul.co.uk/comparison/lossless/index.asp) . (Those figures would have saved you a mighty 499 rather than 485 :-o)

However, the difference from -0 is quite significant.
(I think I remember having squeezed some GBs of flac 1.1.lessthanfour @ -5 files down by a couple of percents though.)
Title: What FLAC compression level are people using these days?
Post by: Remedial Sound on 2012-07-17 20:09:55
- 5... set it 'n forget it!
Title: What FLAC compression level are people using these days?
Post by: IgorC on 2012-07-18 02:02:57
The same but old poll.  http://www.hydrogenaudio.org/forums/index....showtopic=58731 (http://www.hydrogenaudio.org/forums/index.php?showtopic=58731)
Title: What FLAC compression level are people using these days?
Post by: Soap on 2012-07-18 03:07:50
- 8... set it 'n forget it!

I can't measure the difference at the wall in power consumption between encoding (nor playing) -5 and -8.  -8 may offer only the most marginal of gains but it appears to cost me nothing.
Title: What FLAC compression level are people using these days?
Post by: A_Man_Eating_Duck on 2012-07-18 06:23:34
I did a test a while back on 300+ full albums and this is what I came up with

(http://img235.imageshack.us/img235/9664/losslesspercentdq8.png)

this is mainly rock music though.

http://www.hydrogenaudio.org/forums/index....c=61054&hl= (http://www.hydrogenaudio.org/forums/index.php?showtopic=61054&hl=)
Title: What FLAC compression level are people using these days?
Post by: probedb on 2012-07-18 08:48:07
-8. It's not like one takes any noticeable length of time longer these days.
Title: What FLAC compression level are people using these days?
Post by: Porcus on 2012-07-18 10:02:18
By the way, I also verify after encoding (as dBpoweramp supports that). Not because I think there is any bug in the reference flac.exe which would lead to a an encoded+decoded signal differing from the original, but to increase chances that any issue (HD ...) would be detected.

In Synthetic Soul's test, this step would add 10 percent to the -8 encoding time (and 40 percent to -5).


And for those cases where I reencoded: I do not trust overwrite with --force. Encoded to different target folder, foo_bitcompare, then remove.
Title: What FLAC compression level are people using these days?
Post by: pdq on 2012-07-18 12:38:24
I did a test a while back on 300+ full albums and this is what I came up with ...

I notice that the difference between FLAC -5 and -7 is especially small, only 0.06%. This means that if you compressed 1600 CDs with -5, you would be able to compress 1601 with -7 in the same space.

I use -5 because it was the default, and I had no issue with either speed or file size with this setting.
Title: What FLAC compression level are people using these days?
Post by: jensend on 2012-07-18 17:34:06
The poll needs options for FLACCL.

The exhaustive model search that FLAC uses for -7 and higher involves a tremendous amount of added work for very little gain. I would never ever bother with -7 or higher on the standard encoder. The developers knew what they were doing when they made -5 the default.

But it appears that this tremendous amount of work is embarrassingly parallel and reasonably well suited for GPU computation. I don't own a GPU with enough power to give a real advantage, but for those who do, FLACCL rather drastically changes the tradeoff between encode speed and compression ratio.

If you're absolutely certain you need that last tiny bit of compression gain and you aren't using FLACCL, you should look at using another format instead. FLAC is not designed to push the extreme limits of lossless compression, it's designed to hit a sweet spot on the tradeoff curve. If you're really willing to endure a ~3x slowdown from flac -5 for little benefit, instead of using flac -8 and getting a negligible improvement you could get a still-small-but-10x-bigger improvement by moving to TAK's insane compression.
Title: What FLAC compression level are people using these days?
Post by: Soap on 2012-07-18 17:48:59
If you're really willing to endure a ~3x slowdown from flac -5 for little benefit, instead of using flac -8 and getting a negligible improvement you could get a still-small-but-10x-bigger improvement by moving to TAK's insane compression.


I'm not willing to endure a 3x slowdown for the marginal gains of -8.  Yet I use -8.

Thankfully I don't compress to FLAC with a slide rule, and my demands for FLAC files are never mission time critical.  My computer has more than enough processing power to perform the operation in the background without affecting what I'm doing in the foreground nor measurably affect the VA pulled by the computer (as measured by my kill-a-watt.)
Title: What FLAC compression level are people using these days?
Post by: eahm on 2012-07-18 19:55:23
Just another simple test (CPU specs: http://i46.tinypic.com/110lytc.png (http://i46.tinypic.com/110lytc.png):)):

Pink Floyd - The Wall (2011 Remaster) WAV 819 MB

-5: Total encoding time 004.836, 1006.87x realtime 444 MB (466,053,562 bytes)

-6: Total encoding time 005.242, 928.89x realtime 444 MB (466,043,822 bytes)

-7: Total encoding time 012.589, 386.78x realtime 444 MB (465,811,133 bytes)

-8: Total encoding time 017.863, 272.58x realtime 443 MB (465,150,733 bytes)


Can a moderator please reset/change my vote to -5 please? I did few more test and it seems more efficient, a lot more, even than -6. Thanks.
Title: What FLAC compression level are people using these days?
Post by: IgorC on 2012-07-20 21:22:20
Probably the poll could be a bit more complete with some extra options like

-8 -A tukey(0.5) -A flattop http://www.hydrogenaudio.org/forums/index....showtopic=58731 (http://www.hydrogenaudio.org/forums/index.php?showtopic=58731)
FLACUDA www.cuetools.net/wiki/File:Flaccl3.png (http://www.cuetools.net/wiki/File:Flaccl3.png)
Title: What FLAC compression level are people using these days?
Post by: db1989 on 2012-07-20 23:15:07
@eahm: done!
Title: What FLAC compression level are people using these days?
Post by: _m²_ on 2012-08-19 11:14:39
Back when I used flac, I used the strongest mode of flake (because it was stronger than the original).
Title: What FLAC compression level are people using these days?
Post by: extrabigmehdi on 2012-08-19 11:38:31
It depends of the computer I use.
With a quad core, I don't mind the additional time to compress at the 8 level.
While with a dual core,  I prefer to  use the 5 level.
Title: What FLAC compression level are people using these days?
Post by: Anakunda on 2012-08-19 12:08:51
Is there any senseful reason to use anything else than 8 nowadays when it comes to  libFlac?
Title: What FLAC compression level are people using these days?
Post by: detmek on 2012-08-19 13:07:58
3-4x longer encoding time for 0,5% saved disk space, maybe?
Title: What FLAC compression level are people using these days?
Post by: extrabigmehdi on 2012-08-19 16:47:08
3-4x longer encoding time for 0,5% saved disk space, maybe?


With a powerful machine, the additional encoding time is not a big matter i.e it's still enough fast.
Unless you have too much stuff to encode.
Title: What FLAC compression level are people using these days?
Post by: detmek on 2012-08-19 17:38:42
Well, using level 8 during ripping isn't a problem as ripping is way slower then FLAC transcoding. But, I don't think it's... ecological to transcode hundreds of FLAC albums.