FLAC files from 16/44 CD (WAV) files are smaller than MP3s.

[mansr]

If you post a sample file exhibiting the phenomenon, someone can probably explain it.

[mansr]

2 minutes ago, dalethorn said:

It's supposed to be "DSD64" I think, but if I'm remembering right, the sample rate is 352.

The sample rate of DSD64 is 2.8224 MHz, that is 64 * 44.1 kHz.

[mansr]

5 minutes ago, dalethorn said:

By my calculation, that would mean the player has to process 11.5 mb per second, which is quite a feat for the free Vox player on the little Macbook 12-inch I have.

That's only a little more than DVD bit rate. Mid-90s PCs could play DVDs, and that requires a lot more processing.

[mansr]

21 minutes ago, dalethorn said:

Amazing how bad copy and paste is on these computers...

 

https://www.dropbox.com/sh/st6goiq1q0mjmsz/AACgOP4f6dQLD4m0KLWlb8yJa?dl=0

Here's the spectrogram of that:

 

There's hardly any content above 5 kHz. No wonder it compresses well. This typical of piano music.

[mansr]

The posted WAV compresses to 24% of original size using the reference FLAC encoder at level 5. A 16/44 WAV converted from the DSD file with Sox compresses equally well. Seems to me it's simply a music track that compresses unusually well.

[mansr]

2 minutes ago, dalethorn said:

If you would read my long post, it asks why:

 

1) The FLAC converter never went below 55 percent on thousands of other conversions.

Yes, 50-60% is typical. This piano piece is much simpler than average music and thus compresses better. I admit 24% is pretty unusual though.

 

2 minutes ago, dalethorn said:

2) JRiver's conversions to 24/88 totally corrupted my Foobar player.

That's obviously worrying. Could you share one of these "toxic" files?

 

2 minutes ago, dalethorn said:

3) My Foobar player plays over a thousand 24/88 to 24/192 HDTracks and other sites' downloads perfectly.

I'd hope so.

 

2 minutes ago, dalethorn said:

4) My Foobar conversion of a 128 k (or 320 k) MP3 to FLAC still makes a FLAC file several times larger than the MP3.

That's to be expected.

 

2 minutes ago, dalethorn said:

The "low resolution/content" does not explain any of the above.

What is the source of the DSD files?

[mansr]

4 minutes ago, dalethorn said:

It cannot be purely a compression issue, as I've explained many times when converting from MP3 to WAV to FLAC.  The FLAC codec is behaving totally out of character, and only with JRiver's file.

I don't see any issue, compression or otherwise. As I said, converting from DSD with Sox gives the same result. The mp3 comparison is irrelevant. Decoding mp3 produces lots of artefacts that although not present in the original must be preserved by the FLAC encoder.

[mansr]

4 minutes ago, dalethorn said:

I didn't want to get into this DSD stuff because I've been suspicious of hidden DRM, or in the case of this 16/44 WAV file, possible "effective" DRM by stripping out the high-res data.

Nothing of the sort is going on.

[mansr]

7 minutes ago, esldude said:

This is interesting.  Beginning with the 88/24 wav I converted to 44 with Ogg Vorbis set on a quality level of 5 out of 10.  The file size was only 2.5 meg.  While I know ogg is more like MP3 that is a lot of compression.  High rate VBR MP3 was 4.4 meg.  I think it is simply a compression issue. 

It's a solo piano piece. Of course it compresses well. Piano music is as simple as it gets. That said, I'm a bit surprised at just how well it compresses. Still nothing to be concerned over though.

[mansr]

1 minute ago, dalethorn said:

Says who?

I do.

 

1 minute ago, dalethorn said:

In the face of the history of music companies struggles to protect their music.

NativeDSD are honest. They wouldn't try anything sneaky. Besides, the DSF format doesn't permit it, even if they wanted to.

[mansr]

1 minute ago, dalethorn said:

BTW, name one CD of solo piano music that will compress to 20+ percent of WAV size to FLAC.  I will buy it now and test it immediately when it arrives.

I'll check my collection tomorrow.

[mansr]

3 minutes ago, dalethorn said:

If you read my piece, it wasn't pointing to NativeDSD, it pointed to the JRiver conversion.

I got the same result converting your DSD file with Sox.

[mansr]

3 minutes ago, dalethorn said:

No it is not the answer.  The answer is when you have something that can be verified by everyone.  A CD that I can buy and test myself.

You already provided files that can be verified by anyone. What exactly do you think is wrong with them?

[mansr]

17 hours ago, dalethorn said:

BTW, name one CD of solo piano music that will compress to 20+ percent of WAV size to FLAC.  I will buy it now and test it immediately when it arrives.

Here you go: https://www.amazon.com/Debussy-C-Complete-Preludes-Illumines/dp/B002XC7FQA/

 

Compresses to about 24% of original size.

[mansr]

1 hour ago, CatManDo said:

Could this have to do with the treatment of mono recordings (the 1955 Goldberg Variations are mono)?

The files dalethorn posted are not mono, nor is the Debussy album I suggested. However, piano recordings still have strongly correlated channels, and this helps compression.

[mansr]

51 minutes ago, dalethorn said:

It all gets much more interesting when FLAC sizes are as small as or smaller than MP3s.

Not if you understand how those compression methods work.

[mansr]

2 minutes ago, audiventory said:

There is one hypothesis that FLAC uncompression boost computing intensity and electromagnetic radiation, thus noise level.

That has nothing to do with compression ratios achievable with various inputs.

[mansr]

9 minutes ago, audiventory said:

There is uncompressed FLAC, that was created to avoid additional processing.

Still not relevant to this discussion. And that's not the reason such a FLAC can be created either.

[mansr]

23 minutes ago, dalethorn said:

I'm not so sure.  I think you agree that the 16/44 FLAC is lossy compared to the master, so the question is, what's thrown away?

Frequencies above 22 kHz are discarded, as are details below 16-bit precision.

 

Quote

I appreciate that there's a sample rate that has to be adhered to for the players that can't go above 16/44, but still, someone is making the decision what to discard, and I doubt it is (or has to be) merely cutting the output data by 4 times. I'm guessing it's more complicated than that, and there are options...

The only options you have are the nature of the low-pass filter and what, if any, dither shaping to use. Both are minor tweaks, nothing more.

[mansr]

12 minutes ago, dalethorn said:

I'm getting the impression, and I could be off-base here, that a very clean recording might compress a lot better than a "dirtier" recording that has extraneous noise, but the same number of instruments, i.e. solo piano.

This is correct. Noise compresses poorly, and even a little added to a clean signal reduces the compressibility. You can see this easily by generating a pure sine tone, e.g. with Audacity. This will compress very well. If you add some noise, it will compress less.

[mansr]

3 minutes ago, dalethorn said:

I've been digging out solo piano CDs for a couple of days and receiving some in the post, and today I finally ripped a CD to WAV that I converted to Level 5 FLAC at 22.2 percent of the WAV size.  The closest I had come to this previously was above 35 percent, so this must be one unusual recording.  Chandos label, Debussy, Complete Works Vol.1, Jean-Efflam Bavouzet.  Maybe sometime today or tomorrow I can discover what makes this CD so unusually compressible.

Incidentally, that was the first album I checked.

[mansr]

4 minutes ago, audiventory said:

Probably, there is low music time density. As rule FLAC compression about 60% of original PCM.

Piano music typically compresses more.

[mansr]

2 hours ago, dalethorn said:

I've been digging out solo piano CDs for a couple of days and receiving some in the post, and today I finally ripped a CD to WAV that I converted to Level 5 FLAC at 22.2 percent of the WAV size.  The closest I had come to this previously was above 35 percent, so this must be one unusual recording.  Chandos label, Debussy, Complete Works Vol.1, Jean-Efflam Bavouzet.  Maybe sometime today or tomorrow I can discover what makes this CD so unusually compressible.

The other 4 CDs in that set compress similarly.

[mansr]

1 hour ago, dalethorn said:

Set?  What set?

The 5-CD complete piano works of Debussy played by Bavouzet.

[mansr]

7 hours ago, dalethorn said:

the quest for truth needs to know why a solo piano CD (or set recorded in kind) is compressing very much smaller than the average piano CD

We already told you why. It is because piano music has simple waveforms that compress well.