FLAC Lossless Uncompressed versus WAV

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JfTM

Re: FLAC Lossless Uncompressed versus WAV
« Reply #20 on: 11 Mar 2012, 01:11 pm »
@skunark

Excellent post :thumb:

rompolompo

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Re: FLAC Lossless Uncompressed versus WAV
« Reply #21 on: 11 Mar 2012, 02:19 pm »
I agree with the conclusion reached in the recent series of Absolute Sound articles comparing WAV to FLAC - that WAV exceeds the audio quality of uncompressed FLAC by a margin of 10% or so.

Allow me to interject...

As FLAC is a compressed data set that represents the actual bit for bit of the original WAV, there are no differences in the files content wise. The issues I have seen are coming from poorly implemented applications that perform badly when readings FLAC files as they need to extract chunks of audio data while in memory. Since that process is done in real time, the better memory management the better the computer will execute its memory I/O.

The problem is that most audiophiles are not computer savvy and seeing the ways they conduct tests is laughable from any computer geek's eyes. On a properly setup PC, I can tell no different between lossless formats where else in a crappy PC with old codecs you can hear a difference. The beauty of the Bryston unit is that it takes away the requirements to properly set up a pc.

FLAC is here to stay. It is open, free and available;e on any platform. The meta data capabilities are a bonus.

Ran

P.S. Don't believe everything you read on the "Absolute Sound"...

rbbert

Re: FLAC Lossless Uncompressed versus WAV
« Reply #22 on: 11 Mar 2012, 03:08 pm »
I agree with the conclusion reached in the recent series of Absolute Sound articles comparing WAV to FLAC - that WAV exceeds the audio quality of uncompressed FLAC by a margin of 10% or so.

Actually, the authors were careful to point out that the difference in their tests was not "10%", but rather 10 points on their visual-analog scale, not the same thing.   Regardless, though, in this area as in several others they are full of hooey.

groovybassist

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Re: FLAC Lossless Uncompressed versus WAV
« Reply #23 on: 11 Mar 2012, 04:50 pm »
I chose to re-rip to WAV vs converting from FLAC to WAV to avoid a second conversion process. May or may not have made any difference, bUt that's what I chose.

In terms of sound quality, I'm only reporting what I heard and what I believe any skilled listener would hear, not why I heard it. The playback chain I used was identical in both cases. I have no idea whether the change in sound quality is due to the files themselves, processing, CPU, memory playback, etc., but it's nonetheless there. From my standpoint, it doesn't matter why one sounds better vs. the other, simply that it does and there's no reason I shouldn't take full advantage of the best sound my system can provide.

calinet6

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Re: FLAC Lossless Uncompressed versus WAV
« Reply #24 on: 11 Mar 2012, 05:16 pm »
skunark, agreed on all points. There's always a possibility that there's user error or another contributing factor, but given the difference between WAV and FLAC using the same source, it's generally going to be equivalent.

Also regarding bugs in the encoding itself, possible but very, very unlikely. If they ever did come up, it would be like you mentioned: blips or audible drop outs, not quality differences. As long as the music still sounds like music, then it's nearly 100% probable that it's exactly the same as the original. Also, FLAC employs a set of testing procedures called "unit testing," which ensure that all of its internal algorithms work correctly, so it's less likely that encoding bugs make it into the released version of the software. That is not to say that all decoders are equal, but again, as long as you can hear the music and don't notice blips or pauses, it's exceedingly likely the quality is exactly equivalent.

Thanks for the great and well-measured reply.

rbbert

Re: FLAC Lossless Uncompressed versus WAV
« Reply #25 on: 11 Mar 2012, 06:08 pm »
The Tape Project tapes (that are in print) are $300 per album, and some other companies that offer similar products are $500 per album.  For OOP the cost is usually higher but dependent on market variables.  I chose $7500 for a tape deck because that's about the cheapest you can find one, but to get one that would equal a $10k SACD player you would probably have to pay at least $10k.  But it's certainly your money to do with what you want, I'm just pointing out that the economics wouldn't work out for most audiophiles.

srb

Re: FLAC Lossless Uncompressed versus WAV
« Reply #26 on: 11 Mar 2012, 06:19 pm »
The Tape Project tapes (that are in print) are $300 per album, and some other companies that offer similar products are $500 per album.  For OOP the cost is usually higher but dependent on market variables.  I chose $7500 for a tape deck because that's about the cheapest you can find one, but to get one that would equal a $10k SACD player you would probably have to pay at least $10k.  But it's certainly your money to do with what you want, I'm just pointing out that the economics wouldn't work out for most audiophiles.

I think you're in the wrong topic?

WGH

Re: FLAC Lossless Uncompressed versus WAV
« Reply #27 on: 11 Mar 2012, 11:09 pm »
I chose to re-rip to WAV vs converting from FLAC to WAV to avoid a second conversion process. May or may not have made any difference, bUt that's what I chose.


I'm going in the opposite direction and converting all my WAV files to FLAC. I think my playback solution (below) bypasses the FLAC vs. WAV controversy. I don't use a BDP-1 so this may be a little off topic regarding the Bryston player but it would be an interesting direction for the next version.

I don't know if the BDP-1 converts FLAC files on the fly like foobar2000 or stores the converted files for playback.The Stereophile review says:

"When a file is selected for play, the BDP-1 first copies the file from the external drive to an internal buffer, thus avoiding the usual jitter problems when data are streamed directly from a USB port. The BDP-1's soundcard outputs the stream via the player's S/PDIF and AES/EBU ports to feed an external D/A processor."

My solution is to use Mike Galusha's FlacWavLoader. The FWL converts FLAC files to WAV and stores them in memory for playback. The FWL can play a mix of files in a playlist so I have listened to songs that were converted from FLAC and then the the WAV version back to back and can detect no differences. FLAC downloads no longer have to be converted for best sound quality, disk space is conserved, and I have tags.

Further reading:
Thread: http://www.audiocircle.com/index.php?topic=100921.0
Website: http://www.mikegalusha.com/

Wayne


groovybassist

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Re: FLAC Lossless Uncompressed versus WAV
« Reply #28 on: 12 Mar 2012, 12:05 am »
I'm not even sure what Mike's program does, but I use a Mac to stream these files and I believe Mike's program works on Windows only.

WGH

Re: FLAC Lossless Uncompressed versus WAV
« Reply #29 on: 12 Mar 2012, 12:52 am »
Yes, unfortunately Mike's program is Windows only. It is amazing for free software, FlacWavLoader turns my fanless low powered computer/music player into a memory player. I store music files on a main computer that is networked to the music player which is similar to but not as refined as the BDP-1. FWL is installed on the music player and can also access an internal hard drive, external USB drive, thumb drive, or a wireless connection to a server, pretty much anywhere music files are stored. It is pretty basic, no searching or playlist functions; it kind of works like vinyl - pick an album or songs from an album, convert and play using the software player of your choice (foobar, Windows Media Player Classic, maybe even iTunes)

Mac users would have to go to the dark side and install Windows7 using Parallels.

Music Matters

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Re: FLAC Lossless Uncompressed versus WAV
« Reply #30 on: 12 Mar 2012, 02:18 pm »
Once again, since I started this thread, I will chime in. First of all, I am most appreciative of all of the information that has been offered, from the technical to the more subjective. I would like to clarify one mis-statement that I made about the Absolute Sound article (actually in the March 2012 response to a letter to editor) on the issue of FLAC vs. WAV. The threads herein are correct - the article said uncompressed FLAC bettered the parent WAV file sonically by 10 "points", not "percent" as I incorrectly stated.

Regardless, my point was that in my system and all other things being equal in the comparison, I found incremental sonic differences to WAV over uncompressed FLAC. I do not know from a technical standpoint why that is the case and quite frankly had been hoping that my ears were not correct since I had originally ripped all of my CDs to FLAC uncompressed. But there is a difference in overall sound quality that gives WAV or AIFF a slight edge in my system and anyone with a good set of ears listening to my gear in my room would likely have come to the same conclusion. Again, this is not an issue of a stunning difference. They are a bit subtle, particularly in the area of bass response, timbre, and soundstage. But the differences are there. Unknown why from a technical standpoint. Thanks again for all of the comments and information offered by all of you who continue to contribute to this topic!!

Music Matters

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Re: FLAC Lossless Uncompressed versus WAV
« Reply #31 on: 12 Mar 2012, 02:33 pm »
In my post above, the correct Absolute Sound issue is April 2012, under the letter titled "The Flack Over FLAC".

tonyptony

Re: FLAC Lossless Uncompressed versus WAV
« Reply #32 on: 12 Mar 2012, 03:02 pm »
Many of us who've used Squeezboxes felt early on there was a small difference in sound quality between FLAC and WAV. After a bit of experimentation it seemed that sending the FLAC data to the SB and allowing it to do the FLAC->WAV conversion internally had something to do with the slight degredation in sound quality. As the SB server software is pretty well designed, it allows for the option of doing the FLAC->WAV conversion on the server side as an alternative. In my case (and in others') the server side conversion does make for a slightly better sound.

What I'm struggling with in particular in the AS articles is the conclusion that FLACs coverted back into WAVs did not sound as good as the original WAV rip. It's been shown by more than a few people that you could WAV->FLAC->WAV->FLAC->WAV all day long and the checksum and bit-for-bit exactness of the final WAV will match the original. I've done it myself (cycling through about 10 conversions) and I can't say the final WAV sounds any different than the original (yes the data checked out bit identical). Either I'm missing something or this conclusion in the AS article is questionable at best. I suppose it's possible if one used different versions of the FLAC encoder/decoder along the way, but even in that case I would think you'd eventually get a bit mismatch.

rbbert

Re: FLAC Lossless Uncompressed versus WAV
« Reply #33 on: 12 Mar 2012, 06:03 pm »
You can't get a bit mismatch in WAV>FLAC>WAV without an error message because checking checksums is part of the FLAC protocol.

There are many questionable conclusions in the TAS articles; in most thinking audiophiles' minds the only firm conclusion is that there may be audible differences between different hardware/software combinations.

skunark

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Re: FLAC Lossless Uncompressed versus WAV
« Reply #34 on: 12 Mar 2012, 07:06 pm »
You can't get a bit mismatch in WAV>FLAC>WAV without an error message because checking checksums is part of the FLAC protocol.
You are assuming that the convertor is generating a checksum for the WAV file at every step and comparing it to an online database?     

I think we are a bit hung up on the flac codec.    I think it's safe to say the conversion between WAV, FLAC, AIFF, or ALAC can be done correctly, sure bugs can exist here, but low probability.  The checksums help, but if the encode is bad to begin with then how useful is it?    Solutions like EAC are highly recommended, but still dependent on the drive used to perform the rip, makes you ponder why all rips are not equal..   

The difference in sound quality can be attributed to other variables, and more likely these other variables...   For example, how well do the application and sound card driver interact for a given codec.   With features like volume normalization, oversampling, upsampling, etc, there's enough options during playback that will alter the bit-stream.  It's very unlikely that the BDP is doing any of that, you can review the settings to find that it's not intentionally tweaking the PCM stream, but that doesn't mean there aren't other factors. 

It would be hard to agree with anyone that makes the bold statement that one lossless codec is simply better than all others with a big period..   It's also hard to agree with anyone that a given codec sounds better on a given transport, but to me, this is a little more acceptable based on the number of options we are faced with digital playback.

I would be curious to know what tests Bryson has performed with the BDP with the various file formats.  James if you are reading this, is this something you can share?

Btw, what is exactly is "10 points"?  Guess I should go read that article to understand their scale.     

Jim

brother love

Re: FLAC Lossless Uncompressed versus WAV
« Reply #35 on: 12 Mar 2012, 07:54 pm »
Since I am in the infant stages of ripping 300 CD's or so, I am reading this thread w/ great interest .... and confusion.  :lol:

Oh, & for those interested, this topic was discussed in The Discless Circle last year by fellow AC members:

http://www.audiocircle.com/index.php?topic=92852.0


skunark

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Re: FLAC Lossless Uncompressed versus WAV
« Reply #36 on: 12 Mar 2012, 08:05 pm »
Since I am in the infant stages of ripping 300 CD's or so, I am reading this thread w/ great interest .... and confusion.  :lol:

Oh, & for those interested, this topic was discussed in The Discless Circle last year by fellow AC members:

http://www.audiocircle.com/index.php?topic=92852.0

I think it's safe to say this is directed towards the BDP, but yeah, this topic has been discussed numerous times generically and with other devices.   

rbbert

Re: FLAC Lossless Uncompressed versus WAV
« Reply #37 on: 12 Mar 2012, 10:17 pm »
You are assuming that the convertor is generating a checksum for the WAV file at every step and comparing it to an online database?     

I'd have to go back to the FLAC page and review the exact protocol, but IIRC the WAV>FLAC encoding generates a checksum of the original WAV file and includes in the FLAC file.  When the subsequent FLAC>WAV conversion occurs, a checksum for the new WAV file is generated and compared to the checksum (included in the FLAC file) for the original WAV file; if they don't match, an error message is generated.  I don't know if this occurs with on-the-fly FLAC>WAV conversion, but there have been users who report that the digital output in this case still matches that of the original WAV file.  In my mind, that doesn't guarantee that there wouldn't be timing errors with the on-the-fly converted file (similar to what occurs without an asynchronous USB connection), but I really haven't investigated that possibility.

adprom

Re: FLAC Lossless Uncompressed versus WAV
« Reply #38 on: 13 Mar 2012, 12:45 am »
Experienced EE here :)

Does this mean you actually have a qualification, or you just happened to have done some technical work? For what its worth, I have a Bach Eng (mixture of electronic and software).

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Is there such a thing as bug free software?  I'm rather shocked anyone would consider flac or any codec bug free.   I assume your findings with flac is limited to a small subset of tests, but please do post your results, would be interesting to see.  I assume you are not aware about Flac's changelog and their bug tracker that can disprove your outcome.  There's several bugs there and that's not even the complete stack, so who knows what other bugs exist upstream or downstream of the codec!   Every codec is bound to have bugs even if the algorithms, mathematics and provability are sound...  Even how the software is compiled can introduce bugs which is why you see a big push for integer only compiles for these codecs.

You attempt to confuse the real issue here. The flac codec, as has been shown across many many tests, produces a bit perfect ouptut. As many have tested, the bitstream output from the sound card is perfect to the original source. If there was a bug, then it would need to affect the actual ouput. Of course, what you are referring to on the bugtracker are things which are metadata related, or cause the software to fail completely. i.e. a buffer overflow is listed in that changelog. What you have failed to mention, is that none of the changes are affecting the integrity of the core encoding and decoding which has been shown to have excellent integrity.

No different to using a zip file on a computer.

The real test is, what you get in, is what you get out which holds true with flac. In fact, the encoder even tests it. It is in fact how I found out I had a faulty memory stick in my desktop - because the encoder was producing erroneous outputs and was telling me that it was!

So you have used a strawman argument to misrepresent the bug argument which doesn't hold.

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I have experience issues with ALAC files on the BDP-1 that doesn't exist with other players.  These issues include hangs partway through a track and sometimes would pops/glitches between tracks and all reproducible.  Clearly some issue with ALAC and the BDP.  You can google about the quality of various AAC codecs and the issues there, but that is lossy format and will never be bit-perfect so might be a little uninteresting. 

So you've referred to a lossy codec.  Completed unrelated to the topic here and has no bearing whatsoever. As for the clicks between tracks, or hanging - then you are referring to potential glitches in the BDP-1 implementation - and nothing which happens to change the ouput - but are an outright fail. In particular, the pops between tracks has to do with an implementation of gapfree playback which has nothing to do with the codec. The codec is likely working 100% perfectly, but there is an unrelated glitch causing an issue. Not to mention, the way the codecs work - they aren't issues which question the integrity of the output of the codec here. You are confusing general usability and device bugs with the integrity of a codec. Different issues.

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A broader set of regressions with various hardware and software combinations will indicate there are bugs....

What on earth are you talking about? What are these regressions? Does the zip format, for data file compression exhibit this behaviour?

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Sure in academia where everything is ideal, you can formally prove they are equivalent, but in the real-world, there's a few more twists and turns. ..... Even Squeezebox users have reported issues around various codecs and how everything gets converted to FLAC before streaming. 

Actually no.... Plenty of people have verified the flac codec (amongst others) actually does what it says for the basic encoding and decoding functionality. Unless you have a hardware fault, it will work. Thanks to the error checking in the format - it will actually let you know if there is any loss of integrity! Don't try to confuse this with an academic argument to confuse the issue. This has practically been tested and verified.

A zip file doesn't just randomly not work when you decompress it. These things are not as complex as you are making out.

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I just opted to switch to an uncompressed and more mature format.  Using the notion that all lossless formats are bit-perfect, assuming no bugs

Mature? You use the word as if software grows like a child - it does not - it is a discrete process... By nature of the way software is designed, especially something extremely mathematical such as the encoding and decoding, it can be mathematically proven that the core algorithm is bug free. Sure,might be some bugs to do with tagging etc, but that does not affect the core decoding and encoding functionality. If the lossless formats aren't bit perfect - they are found out very quickly.

Flac is no different to a zip file - using your theory, every so often a zip file should just randomly fail - because there is a bug. I have never had a zip file compression, or decompression fail (unless the archive is corrupt through other means).

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Now why would one feel that one lossless format is X% better than another, vs my experience where there was a huge failure in playback?    I think the squeezebox users probably could shed some light on this too.

Because they want to. There are some squeezebox users who do some ludicrous stuff swearing by better quality. Most of it is people 'tweaking' for the sake of it and wanting to hear something better because they did something. A purely psychoacoustic effect.

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I would agree that it's highly unlike there is an actual difference between the uncompress lossless formats, but I also don't mind scratching my head pondering why it could be different.

The truth is often far more boring than people like - and in cases such as the above, psychoacoustics is often the boring answer. The other, less boring answer is that the particular user has a hardware fault.

You are assuming that the convertor is generating a checksum for the WAV file at every step and comparing it to an online database?     

I think we are a bit hung up on the flac codec.    I think it's safe to say the conversion between WAV, FLAC, AIFF, or ALAC can be done correctly, sure bugs can exist here, but low probability.  The checksums help, but if the encode is bad to begin with then how useful is it?    Solutions like EAC are highly recommended, but still dependent on the drive used to perform the rip, makes you ponder why all rips are not equal.. 

As per my zip file comment, if the bugs you suggest above existed, they would have been found out a long time ago. Anything which affects the core functionality. Now you are confusing the issue by comparing different ripping drives. Well that is a real, but different issue. All rips are not equal, but for any given rip - the flac output and wav output are.

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The difference in sound quality can be attributed to other variables, and more likely these other variables...   For example, how well do the application and sound card driver interact for a given codec.   With features like volume normalization, oversampling, upsampling, etc, there's enough options during playback that will alter the bit-stream.  It's very unlikely that the BDP is doing any of that, you can review the settings to find that it's not intentionally tweaking the PCM stream, but that doesn't mean there aren't other factors. 

A sound card doesn't even know what a flac or wav file is (usually). All it gets is a PCM stream. The application will simply use the codec for whatever container, decode it - get the output and send it to the sound card. So the application actually handles the file format. The output from the application to the sound card (or to the driver in most cases) will be identical. To suggest there is a difference is to suggest that the data must inherently be different somehow. At this stage of the process, it won't even affect jitter as the sound card, or output will buffer the stream anyway.

I haven't really covered jitter much. However, the main influence on jitter will be the hardware used in the output stage, or sound card. The data from the software decoding is buffered before it is output making the codec used irrelevant. I also saw the mention that cpu usage may effect noise etc... In hardware devices such as the BDP-1, there is usually a chip doing hardware decoding of the codecs before outputting it. Either way, if it is done in software, it hardly requires any processing power anyway. I'd be surprised if you can even measure any theoretical power increase.

Of course, it defeats the fun when we let good electrical and software engineering get in the way of the need for people to 'feel an improvement'.

How about asking for firm scientific evidence that there is a difference? I have certainly never seen any... Has anyone ever done an ABX test, and managed to verify the difference? I've seen this same argument on many forums - and the standard responses promoting differences always have a scattergun approach (essentially a FUD arguemnt) of loosely related computer analogies (i.e. software bugs, software regression, power usage, software/hardware integration or combinations) to justify the idea that there might be a possibility even though no objective evidence supports the concept.

In fact many of the arguments presented are entirely illogical as they would make computing as we know it impossible. We could never be certain of any behaviour with software. Yet somehow when it comes to audio, software and electronics somehow take on a far less predictable state and all these differences become possible.

Many of the lossless arguments are defeated simply by looking at how a rudimentary zip file works.

adprom

Re: FLAC Lossless Uncompressed versus WAV
« Reply #39 on: 13 Mar 2012, 12:51 am »
Just found a decent resource with some tests: http://thewelltemperedcomputer.com/KB/WAV-FLAC.htm

There is a quote at the end referring to people choosing wav 82% of the time - but nothing to back it up or testing methodology.