Flac files generated from Audacity

[Dave2002]

I did not know that Audacity is capable of generating Flac files. It is - apparently.

I recently tried this to avoid posting huge files online.

However I have noticed some unwanted jumps in audio levels in Flac files generated from Audacity, so assuming that Flac really is lossless encoding, as I've been led to believe, there are problems with the way Audacity does the conversions.

Pity!

[Bryn]

I did not know that Audacity is capable of generating Flac files. It is - apparently.

I recently tried this to avoid posting huge files online.

However I have noticed some unwanted jumps in audio levels in Flac files generated from Audacity, so assuming that Flac really is lossless encoding, as I've been led to believe, there are problems with the way Audacity does the conversions.

Pity!

If using Windows 10, I'd suggest relying on FLAC Frontend, if Audacity is causing problems. Otherwise, there are numerous remarks about using Audacity and FLAC to be found via Internet searches. Software versions appear to be of some concern.

[Maclintick]

If using Windows 10, I'd suggest relying on FLAC Frontend, if Audacity is causing problems. Otherwise, there are numerous remarks about using Audacity and FLAC to be found via Internet searches. Software versions appear to be of some concern.

I've had no problems exporting FLAC files in Audacity 3.2.2 for Mac. Recently I attempted to update to v.3.2.3 but this failed at the verification stage.

[Dave2002]

I've had no problems exporting FLAC files in Audacity 3.2.2 for Mac. Recently I attempted to update to v.3.2.3 but this failed at the verification stage.

Just checked my version of Audacity - recently updated. It's 3.2.4.

I assumed it was OK until noticing the issue mentioned. Clearly not "life threatening" for me, though it is a matter of concern. I assumed that the Flac encoding would merely result in a smaller file, not give rise to the kinds of problems mentioned.

Not sure whether I can do a round trip test - convert the flac file back to .wav, and then compare with the original wav file to see if they're the same. It is just possible that the issues actually lie with the audio players on my Macs, which now appear to be able to handle FLAC files as well as most other formats.

[Maclintick]

Just checked my version of Audacity - recently updated. It's 3.2.4.

I assumed it was OK until noticing the issue mentioned. Clearly not "life threatening" for me, though it is a matter of concern. I assumed that the Flac encoding would merely result in a smaller file, not give rise to the kinds of problems mentioned.

Not sure whether I can do a round trip test - convert the flac file back to .wav, and then compare with the original wav file to see if they're the same. It is just possible that the issues actually lie with the audio players on my Macs, which now appear to be able to handle FLAC files as well as most other formats.

Following up your suggestion I converted a 24/96 FLAC file to an equivalent 24/96 .wav in Audacity and then back again to a new 24/96 FLAC. All 3 files had identical waveforms and timings and were AFAICT aurally indistinguishable played via an external interface feeding Sennheiser HD600s. One thing which slightly surprised me was that although both FLAC files were roughly half the size of the .wav, they differed in size by 0.7 MB. I can only assume that this means Audacity has added some extra metadata to the copied file...

[Dave2002]

Not quite sure how you knew the waveforms were identical, unless you did a bit by bit comparison. It is possible to do that, though as you note, it's also possible that the data could be exact, but the meta data could be different. Anyway, glad that your data passed the round trip test to your satisfaction.

I just know that for the particular files I was using/testing there was a definite problem, and I believe it's a repeatable issue, though I don't know what caused it. I had already changed the sampling frequency, but as far as I know, Flac should work with different sample rates. I would now be wary of using Flac generated by Audacity for archive purposes, though I might have considered that in the past.

I could try several different Flac players (if I can find a few more) to see if any of them play the file I already have without the audible glitch in the level. Otherwise the most likely reason for the problem does come back to Audacity.

[Maclintick]

Not quite sure how you knew the waveforms were identical, unless you did a bit by bit comparison. It is possible to do that, though as you note, it's also possible that the data could be exact, but the meta data could be different. Anyway, glad that your data passed the round trip test to your satisfaction.

I just know that for the particular files I was using/testing there was a definite problem, and I believe it's a repeatable issue, though I don't know what caused it. I had already changed the sampling frequency, but as far as I know, Flac should work with different sample rates. I would now be wary of using Flac generated by Audacity for archive purposes, though I might have considered that in the past.

I could try several different Flac players (if I can find a few more) to see if any of them play the file I already have without the audible glitch in the level. Otherwise the most likely reason for the problem does come back to Audacity.

It does sound as if Audacity is the culprit, so maybe it's a problem with v.3.2.4 as Bryn intimates, though it's worth trying other players, VLC, Elmedia, as you say.

On your first point, making bit-by-bit correlations of files is beyond my level of competence, I'm afraid. I compared the waveforms by aligning the .wav and FLAC in a 4-track edl, zooming in to make visual comparisons. This is obviously not foolproof, I grant you, but they looked identical. The 4 track edl played the .wav and FLAC in perfect synchronicity, by the way, with no audible glitches or level discrepancies, so this again suggests that identical waveforms = identical audio.

[ChrisBennell]

I've been using Audacity with Flac files for over 10 years with no problems to speak of. I just checked my version which is 2.3.2 - so it seems I am some versions bhenind others on here! I used to get emails notifying that an upgrade was available but that all stopped some time ago. My current version dates back to 2019, I see.

[Bryn]

I've been using Audacity with Flac files for over 10 years with no problems to speak of. I just checked my version which is 2.3.2 - so it seems I am some versions bhenind others on here! I used to get emails notifying that an upgrade was available but that all stopped some time ago. My current version dates back to 2019, I see.

You know what they say, unless you have a problem, hold back from non-security updates. It looks like most recent updates deal with hardware-specific problems.