Author Topic: Fake Flac? I.e fake lossless.  (Read 1722 times)

Greta

  • Administrator
  • *****
  • Posts: 4124
Re: Fake Flac? I.e fake lossless.
« Reply #30 on: October 31, 2020, 02:33:49 AM »
Unless I misunderstood & they were saying that converting to FLAC could cause data loss & that the only true way of preventing that was to keep the file as a lossless WAV, in which case the same is true of AIFF, etc.

That's exactly what Porn Library was saying. Converting a genuine (wav or aiff) file to flac, causes data loss.

In some articles shared by Andrew, many users experiences are showed.
Somebody says that the wav file sounds better than the equivalent flac, but that could be a matter of player, which is not "built" for reproducing flacs as good as wavs maybe.
And this very interesting article (https://www.hificritic.com/uploads/2/8/8/0/28808909/2016_07_05__final_unabridged_article_part_2_sound_quality_differences_between_wav_and_flac_formats.pdf)
demonstrate how the tags embedded in the flac files causes a worsening in the listening experience.
But again, I think it's not a matter of audio file itself, but an external factor (like a bad player) causing the problem.
Just supposing.
G.

Porn Library

  • Member
  • ****
  • Posts: 326
Re: Fake Flac? I.e fake lossless.
« Reply #31 on: October 31, 2020, 05:05:24 AM »
Converting a genuine (wav or aiff) file to flac, causes data loss.

That's generally what I was getting at and speaking from experience. A while back I had done an experiment and converted a true WAV that I made myself to flac and it murdered it. Playing the flac sounded like a 320k mp3, and then when I checked the WAV form, that's exactly what happened.

And i've even around here a few times downloaded something that I ripped that another member converted to flac just to check and see what the result of others software produced, and it was the same exact result. Now there very well may be a flac converter program out there that will retain the lossless format of the original WAV, but i've yet to see it.

kimhill

  • Member
  • ***
  • Posts: 212
  • instagram.com/kimhill
    • Instagram
Re: Fake Flac? I.e fake lossless.
« Reply #32 on: October 31, 2020, 10:26:11 AM »

    Somebody says that the wav file sounds better than the equivalent flac…

    Somebody is misinformed.
    • Start with uncompressed source: "FileOne.wav"
    • Convert to FLAC: "FileTwo.flac"
    • Convert "FileTwo.flac" back to uncompressed: "FileThree.wav"
    • Compare waveform data (using software) in "FileThree.wav" to waveform data in "FileOne.wav"
    If they are not identical, there is a critical software bug.

    Listening tests are irrelevant, barring some kind of one-off bug, specific to an individual software product.

    This is about 1's and 0's.  [/list][/list][/list]
    « Last Edit: October 31, 2020, 07:58:14 PM by kimhill »

    kimhill

    • Member
    • ***
    • Posts: 212
    • instagram.com/kimhill
      • Instagram
    Re: Fake Flac? I.e fake lossless.
    « Reply #33 on: October 31, 2020, 10:36:31 AM »
    Another way to look at it- what if you zipped an eBook and sent it to a friend, who said the story wasn't as good after unzipping it?

    niknak

    • Member
    • **
    • Posts: 97
    Re: Fake Flac? I.e fake lossless.
    « Reply #34 on: October 31, 2020, 10:57:44 AM »
    I think there's two arguments at play here..

    1, Flac is different?
    2, playback is different?

    1, Take a wav file and get a program that does a CRC check and note the figure it gives you.
    convert that wav to flac
    convert that flac back to wav with a different name and run the CRC checker on it I guarantee 100% you that the CRC's will match, They have to match, they cant call flac LOSSLESS if there's loss!

    2 As for playback, I've seen that white paper before and it should be noted that even Paul the owner of PS Audio says that flac is truely lossless, what is mentioned is the path to speakers and what can be introduced along the way..
    The conversion process it's self is solid, - its not making data up - its just putting the data back in the correct order
    But once that flac is converted back to PCM who knows what can happen, power draw causing jitter? a shitty amp circuit design that takes an extra click to get its caps up to spec because of power draw from the conversion process... who knows... that's beyond the control of the Flac format in itself and is an issue with the playback method.


    kimhill

    • Member
    • ***
    • Posts: 212
    • instagram.com/kimhill
      • Instagram
    Re: Fake Flac? I.e fake lossless.
    « Reply #35 on: October 31, 2020, 11:06:24 AM »
    …what is mentioned is the path to speakers and what can be introduced along the way.

    The software is feeding a list of bits into a DAC. The DAC doesn't care about where the bitstream came from. Amp & path to speakers is downstream from data conversions and not related to FLAC vs. WAV. Jitter is not relevant either. Remember, what we're talking about is all purely in the digital domain.

    Barring massive and easily discoverable software bugs, WAV and FLAC are interchangeable.
    « Last Edit: October 31, 2020, 11:28:05 AM by kimhill »

    niknak

    • Member
    • **
    • Posts: 97
    Re: Fake Flac? I.e fake lossless.
    « Reply #36 on: November 27, 2020, 02:29:34 PM »
    …what is mentioned is the path to speakers and what can be introduced along the way.

    The software is feeding a list of bits into a DAC. The DAC doesn't care about where the bitstream came from. Amp & path to speakers is downstream from data conversions and not related to FLAC vs. WAV. Jitter is not relevant either. Remember, what we're talking about is all purely in the digital domain.

    Barring massive and easily discoverable software bugs, WAV and FLAC are interchangeable.
    Yes I agree. I should of said analogue instead of PCM (brainfart) I was mentioning that the audio path on the analogue side can alter the sound in a general sense, not because it was either flac or wav or dsd or whatever that was coming in upstream - I should of made that clearer my apologies. Clock jitter in DACS is a thing though causing wf distortion on the output, negligible at best though, would need golden ears etc.. 

    digdeeper

    • Member
    • ****
    • Posts: 411
    Re: Fake Flac? I.e fake lossless.
    « Reply #37 on: December 28, 2020, 09:15:56 PM »
    When FLAC means literally "free lossless audio codec", mustn't we assume that there is even no specification, no method for lossy compression..? According to this, there should be no way to use a format that by definition preserves a bitstream to produce a lossy output that cannot be restored to the original bitstream. If the produced FLAC cannot be restored to the complete source, then the software must be at fault. It's as if a zip or rar file couldn't produce the original file, it would equally result in a CRC error, only that the usual FLAC encoder will likely skip the such a check.

    But the reason why I'm bumping this thread is because I started today to take a closer look at my FLAC files, for fear of getting fake FLACs. We all know by now the widespread expectation, sometimes even pressure, to provide FLAC files, and I'm sure within a sharing community such as Soulseek and others, having FLAC versions of something can mean the difference between getting access to another person's shares or being denied access. Some people may be tempted to convert their MP3s en masse to FLAC, and some albums seem indeed to be converted MP3s. Herein lies the danger: having invested time and effort into updating your collection from MP3, only to later learn that you had been fooled. Now you may not even have the original MP3 files anymore, and you're left with fake FLACs that take up precious disk space unnecessarily, and you're facing having to invest even more time into either getting back proper MP3s, or true FLACs. Also, there is always the danger of discarding a high-quality MP3 (good, clean vinyl with proper recording technique @ 320 kbps) in favor of a flawed FLAC (scratched vinyl etc.). I'll be keeping my MP3 versions unless I can be reasonably sure about the quality of the FLAC.

    I've downloaded some tools to check the audio properties of files, such as
    Lossless Audio Checker
    https://losslessaudiochecker.com/
    which scans your FLAC for signs of upscaling, upsampling and transcoding.

    and Spek
    http://spek.cc/
    showing you a spectogram of an audio file (frequency range), revealing, among other things, telltale cutoff points of lossy encodings.
    « Last Edit: December 28, 2020, 11:03:24 PM by digdeeper »

    kimhill

    • Member
    • ***
    • Posts: 212
    • instagram.com/kimhill
      • Instagram
    Re: Fake Flac? I.e fake lossless.
    « Reply #38 on: December 29, 2020, 01:57:56 AM »
    If the produced FLAC cannot be restored to the complete source, then the software must be at fault.

    Sure- FLAC is like zip. As I said earlier, worrying about FLAC quality vs. WAV or AIFF is like zipping an eBook before sending it to a friend- and worrying that the story won't be as good. Any deviation would be nothing but a software defect, and trivially detectable with other tools.

    I'm already on record as a cynic. As far as I'm aware, there's no (credible) record of anyone in the world who can reliably distinguish between uncompressed quality and high-quality encodes with lossy codecs, even with high-end audio equipment. And using mainstream equipment/environments, essentially no one can distinguish.

    That said, I always prefer lossless, because I can trim/edit with no loss of underlying quality, plus I get to make my own encoding choices. And in an age of cheap, fast Internet access, the old penalty of long download times is largely gone. FLAC is a great lingua franca for file exchanges.

    OTOH, if I knew someone who had the same preferences as I do for file prep & encoding, and they were trustworthy about their sources, I would download the lossy encodes every time. My listening experience would be identical, and I'd save loads of time. But I don't know anyone like this, so FLAC is it.

    But then there's the chain-of-custody issue you're talking about. That seems like an insurmountable challenge, unless you're willing to learn & use one of these waveform tools.
    « Last Edit: January 14, 2021, 02:22:36 PM by kimhill »

    stackjackson

    • Administrator
    • *****
    • Posts: 1887
    Re: Fake Flac? I.e fake lossless.
    « Reply #39 on: December 29, 2020, 04:08:12 AM »
    Jeez, I'm old enough to remember when it was thrilling just to be able to listen to one of these records, in whatever quality was available. The progress we've seen in quality enhancement is laudable, of course, but maybe not at the expense of sanity. I guess this is one of those 1st world problems, as the saying goes these days.
    | Stack |

    zach

    • Member
    • **
    • Posts: 99
      • pop pulsations
    Re: Fake Flac? I.e fake lossless.
    « Reply #40 on: December 29, 2020, 04:25:40 AM »
    remember when it was thrilling just to be able to listen to one of these records, in whatever quality was available.

    that's still my ethos.

    kimhill

    • Member
    • ***
    • Posts: 212
    • instagram.com/kimhill
      • Instagram
    Re: Fake Flac? I.e fake lossless.
    « Reply #41 on: December 29, 2020, 09:15:39 AM »
    I'll be keeping my MP3 versions unless I can be reasonably sure about the quality of the FLAC.

    If the "cleanness" of an MP3 is good for you (incl. bitrate and overall production), and if the lead-in & lead-out are good (i.e. if you feel no need to edit the track for any reason), I'm not sure why you'd bother about getting a FLAC version at all. As I see it, the whole process is sort of a "chain is as strong as the weakest link" scenario. Here are (some of the) links:

    ■ Quality of the original studio production
    ■ Quality of the original mastering
    ■ Condition/preservation of vinyl/LP physical media
    ■ Quality of audio hardware for transfer (turntable, electronics, etc.)
    ■ Quality of software tools for digitizing
    ■ Expertise/care of person doing the transfer
    ■ Choice of FLAC vs. high-quality MP3 or AAC

    I'd say the last link is relatively minor by comparison. But it's the link that gets the most attention.

    « Last Edit: December 29, 2020, 09:20:41 AM by kimhill »

    stackjackson

    • Administrator
    • *****
    • Posts: 1887
    Re: Fake Flac? I.e fake lossless.
    « Reply #42 on: December 29, 2020, 02:08:03 PM »
    If the "cleanness" of an MP3 is good for you (incl. bitrate and overall production), and if the lead-in & lead-out are good (i.e. if you feel no need to edit the track for any reason), I'm not sure why you'd bother about getting a FLAC version at all.

    Honestly, this has been my basic approach in deciding what to replace and what to keep. I've come to learn that lossless/FLAC does not always mean "upgrade"
    | Stack |

    digdeeper

    • Member
    • ****
    • Posts: 411
    Re: Fake Flac? I.e fake lossless.
    « Reply #43 on: December 29, 2020, 04:26:34 PM »
    Yes, it's important to keep in mind that quality is the result of a chain of decisions, the file format being one member of that chain. It's like cooking. If the raw materials are bad enough, the best cook in the world is not able to save them - while good raw materials and a decent cook will make for a much better meal.

    kimhill

    • Member
    • ***
    • Posts: 212
    • instagram.com/kimhill
      • Instagram
    Re: Fake Flac? I.e fake lossless.
    « Reply #44 on: December 29, 2020, 09:40:59 PM »
    Another MP3 factor that I've posted about before is the ability to do some edits on MP3 files without the penalty of generation loss, caused by a decode/re-encode cycle. There are native MP3 audio editors for this- I use "Fission" on the Mac, which is pretty simple:

    https://apps.apple.com/us/app/fission/id549251391

    I'm pretty hardcore about trimming over-long lead-ins & lead-outs, and for a long time, I thought you need to convert MP3s to uncompressed for editing. Afterward, you'd need to re-compress this file back to a new MP3, thus adding a generation of quality loss.

    But native MP3 editors let you do this without touching the existing audio data. Lossless editing of lossy files. ;) In fact, you can also do fade-ins/outs, and the editor only touches the waveform during the actual fade, and leaves everything else alone. Voila- the ability to tweak MP3 files without generation loss. This changes the equation for usability of MP3s.

    I still prefer acquiring FLACs, because I can then also make all my own decisions about encoding. I make AACs, not MP3s. And there's no denying FLAC's superiority as an archival format. All the original bits are preserved for whatever use might be relevant in the future.

    All else being equal, I'll definitely prefer FLACs. It's the logical choice for exchanging music and preserving options for every listener, including more sophisticated editing like de-noising – you absolutely want uncompressed for doing work like that. All else is not necessarily equal…
    « Last Edit: December 29, 2020, 10:03:37 PM by kimhill »