Print Page - Bitrate checkers

Support => Questions => Topic started by: audiobabble on March 12, 2022, 09:58:25 PM

Title: Bitrate checkers
Post by: audiobabble on March 12, 2022, 09:58:25 PM

I'd be interested to know what people's experience is of bitrate checker programs and which ones seem to do the best job...

Myself, I have Fakin the Funk, which in general seems pretty accurate although can sometimes bring up false positives.

I just heard mention of Lossless Audio Checker here on the forum so gave that a try.

It doesn't have the same false positives as FTF, but one obvious problem it has is when checking classical music or "quiet" albums such as acoustic & vocal.. all my classical music came out as "upsampled" even though I know for a fact it isn't.

Ultimately, I prefer to trust my ears and can easily pick out a 320 mp3 next to a flac or wav file, although could be (and have been) fooled if all I'm hearing are 320 mp3's

Title: Re: Bitrate checkers
Post by: hiccup on March 12, 2022, 10:07:42 PM

That's an interesting topic.
In the past I tried some apps, but was never impressed (or agreed) with the results/verdicts.

For now I am trusting my ears and Spek (http://spek.cc/), and these ~~two~~ three are serving me quite well.

Title: Re: Bitrate checkers
Post by: frankz on March 12, 2022, 10:47:10 PM

Second vote for Spek. Very helpful for one-offs when added to the Windows right-click->Send To menu or as a button in MB or tool in mp3tag.

When I have a bunch of files that I want to check, I drop them onto this batch file for ffmpeg to generate spectrograms for each. I may have gotten the idea from someone here, but I don't remember (sorry):

Code

@ECHO off
setlocal enabledelayedexpansion
cd %~dp0
FOR %%A IN (%*) DO (
set orig=%%A
set filename=%%~nA
set final="%%~nA.png"
"C:\ffmpeg-latest\bin\ffmpeg.exe" -i !orig! -lavfi showspectrumpic=s=2048x1024:color=rainbow !final!
)
pause

Title: Re: Bitrate checkers
Post by: hiccup on March 12, 2022, 10:59:18 PM

Quote from: frankz on March 12, 2022, 10:47:10 PM

When I have a bunch of files that I want to check, I drop them onto this batch file for ffmpeg to generate spectrograms for each.

Are you doing this (going through this trouble) as a general rite of passage for newly acquired music, or only when you want to compare two versions of the same song/album?
I myself am only doing this sort of stuff when I have two or more versions to compare.
E.g. when a 160kb mp3 seems to sound better than a 320kbps version.
And then Spek usually confirms my suspicions. (not always though)

Title: Re: Bitrate checkers
Post by: audiobabble on March 12, 2022, 11:32:47 PM

Interesting stuff...

So I pulled out a track that Fakin the Funk claims to be 320kbps, whereas it sounds just fine to me (was in fact a recorded HD stream from Amazon HD music, downloaded locally at "highest available" first, then recorded via "loopback" in Audacity)

Spek and ffmpeg give me slightly differing results, what I see in Spek suggests it may well be less than full bitrate, whereas ffmpeg is suggesting it's full-quality (allowing for the slightly different scale on the khz)

Spek:
(https://i.ibb.co/whCSMCy/BBM-Waiting-in-the-wings-05-high-cost-of-loving-spek.png)

ffmpeg:
(https://i.ibb.co/FbLDDnF/BBM-Waiting-in-the-wings-05-high-cost-of-loving.png)

Title: Re: Bitrate checkers
Post by: audiobabble on March 12, 2022, 11:41:23 PM

And here's the same track intentionally saved as a lossy 320kbps mp3

spek:
(https://i.ibb.co/v1bJJv8/BBM-Waiting-in-the-wings-05-high-cost-of-loving-lossy-spek.png)

ffmpeg:
(https://i.ibb.co/HgyH0hy/BBM-Waiting-in-the-wings-05-high-cost-of-loving-lossy.png)

Title: Re: Bitrate checkers
Post by: audiobabble on March 12, 2022, 11:43:06 PM

PS.. my hearing cuts off at 17.5hz, so looks like either way my original is good enough!!

Title: Re: Bitrate checkers
Post by: audiobabble on March 12, 2022, 11:43:41 PM

sorry 17.5Khz ;D

Title: Re: Bitrate checkers
Post by: hiccup on March 12, 2022, 11:43:47 PM

Quote from: audiobabble on March 12, 2022, 11:32:47 PM

…what I see in Spek suggests it may well be less than full bitrate…

What makes you draw that conclusion?
What do you mean by 'full bitrate'?

Title: Re: Bitrate checkers
Post by: audiobabble on March 13, 2022, 12:12:06 AM

Well... I'm a bit new to all this but was reading that if the file is completely lossless I should see frequencies present all the way up to 22Khz, whereas the Spek readout seems to show a cutoff at around 21Khz...

on reflection, comparing it to the deliberately lossy files I can clearly see the difference though!

Title: Re: Bitrate checkers
Post by: phred on March 13, 2022, 12:17:39 AM

Quote from: audiobabble on March 13, 2022, 12:12:06 AM

...comparing it to the deliberately lossy files I can clearly see the difference though!

I'm curious if you can actually -hear- the difference? In a blind test, without seeing the graph beforehand, would you really be able to the difference between same track at 320 mp3 versus FLAC? I have nothing to back this up, but I would guess that most people wouldn't notice a difference.

Title: Re: Bitrate checkers
Post by: audiobabble on March 13, 2022, 12:26:54 AM

Good point... that's the rub really. You're right most people wouldn't hear the difference. And indeed if I walked into a room and heard music playing I would not immediately be able to say "that's 320kbps"...

On the other hand, in an A/B test I think many people, myself included, WOULD hear the difference. It's hard to describe such a subjective thing but I would say it's an increased "solidity" to the bass frequencies and overall clarity and detail in the mids and highs.

Of course what it's being played back on makes a huge difference too.

Title: Re: Bitrate checkers
Post by: audiobabble on March 13, 2022, 12:33:53 AM

Another good test would be... on a nice sunny day, put on some 320kbps music through a decent stereo, open all your windows and then maybe potter in the garden for while. Then put on that same music in a lossless format and do the same. Observe how much more detail you can hear, clarity of lyrics, subtleties of lead instruments and the like

Title: Re: Bitrate checkers
Post by: hiccup on March 13, 2022, 12:49:16 AM

The topic title says 'bitrate', but I am guessing you are thinking of audio frequency range?
(it would be impossible to dissect something like an original bitrate from a lossy audio file)

My eye usually goes out to abrupt changes in density at specific frequencies.
I find that tracks that have a smooth display of frequencies from top to bottom are usually better than ones that have some abrupt stepping stones, even if it displays higher frequencies.
I am guessing some encoders are 'guessing' absent higher frequencies and add them themselves. (or just high frequency noise perhaps)
So only looking at how high the frequencies go is not paramount, nor 'proof' for me.

Title: Re: Bitrate checkers
Post by: frankz on March 13, 2022, 12:59:42 AM

Quote from: hiccup on March 12, 2022, 10:59:18 PM

Quote from: frankz on March 12, 2022, 10:47:10 PM
When I have a bunch of files that I want to check, I drop them onto this batch file for ffmpeg to generate spectrograms for each.
Are you doing this (going through this trouble) as a general rite of passage for newly acquired music, or only when you want to compare two versions of the same song/album?

Not that I would ever do this, but say hypothetically someone downloads a playlist's worth of flac files from different artists and albums and wants to see if any of these flacs are just lossless files derived from a lossy source. Dropping all of the flacs on the batch file and seeing if any look decimated in the upper frequency ranges like the spectrograms in this post (https://getmusicbee.com/forum/index.php?topic=36290.msg198782#msg198782) would be an efficient way to accomplish this.

That person, maybe being older with age-degraded hearing, wouldn't be so concerned with frequency range but rather just in knowing he (or she) had a true lossless version.

Title: Re: Bitrate checkers
Post by: hiccup on March 13, 2022, 01:07:08 AM

Quote from: phred on March 13, 2022, 12:17:39 AM

In a blind test, without seeing the graph beforehand, would you really be able to the difference between same track at 320 mp3 versus FLAC? I have nothing to back this up, but I would guess that most people wouldn't notice a difference.

Depending on the quality of the equipment, the recording (acoustic ambience etc.), and (probably most important) 'knowing what to listen to', it's not so hard to identify lossy vs. lossless.
But for most people, for most recordings, for most equipment it will be extremely difficult if not impossible indeed.

Title: Re: Bitrate checkers
Post by: hiccup on March 13, 2022, 01:22:54 AM

Quote from: frankz on March 13, 2022, 12:59:42 AM

Dropping all of the flacs on the batch file and seeing if any look decimated in the upper frequency ranges like the spectrograms in this post (https://getmusicbee.com/forum/index.php?topic=36290.msg198782#msg198782) would be an efficient way to accomplish this.

This is a lossy mp3:

(https://i.imgur.com/5sJaxFe.png)

Would you have guessed looking at the spectrum?

Title: Re: Bitrate checkers
Post by: frankz on March 13, 2022, 03:28:53 AM

Obviously not. I guess I'm a fool with a bunch of fake flacs in his collection.

Title: Re: Bitrate checkers
Post by: hiccup on March 13, 2022, 09:26:04 AM

Quote from: frankz on March 13, 2022, 03:28:53 AM

Obviously not.

The one thing that gives it away is if you look the first ten seconds. There at 16kHz you see a step in the density.
That's something you'll almost always see with mp3's.
Opus files don't have these 'steps', but Opus has a hard frequency limit at 20kHz, which you will often notice if you compare it against the lossless version.

Title: Re: Bitrate checkers
Post by: vincent kars on March 13, 2022, 12:43:33 PM

Quote from: audiobabble on March 13, 2022, 12:12:06 AM

if the file is completely lossless I should see frequencies present all the way up to 22Khz

Can be the case but it depends very much on the recording.

The highest possible frequency a PCM audio file can contain is half the sample rate (Shannon/Nyquist)
So in case of CD it is 44.1/2=22.05
To avoid any frequency above 1/2 fs, a filter is used. A filter always has a slope so needs some "space"
In practice you will see frequencies up to 21 kHz and then a very steep drop.
(https://www.thewelltemperedcomputer.com/Pictures/KB/FreqRange)

However, this is what is technically possible, not to be mistaken for the properties of the recording.

(https://www.thewelltemperedcomputer.com/Pictures/Software/util/spek.jpg)
This is rip of one of my CD's. It is a string septet. Indeed lossless and no musical life above 15 kHz.
Almost all chamber music on CDs form the 80's, 90's behave this way.

Title: Re: Bitrate checkers
Post by: audiobabble on March 13, 2022, 02:43:20 PM

Quote from: hiccup on March 13, 2022, 09:26:04 AM

Quote from: frankz on March 13, 2022, 03:28:53 AM
Obviously not.
The one thing that gives it away is if you look the first ten seconds. There at 16kHz you see a step in the density.
That's something you'll almost always see with mp3's.
Opus files don't have these 'steps', but Opus has a hard frequency limit at 20kHz, which you will often notice if you compare it against the lossless version.

I'd have to disagree with that, surely the step in density is to do with what is happening in the music. It's very rare that you will find a track that starts at full volume from the get-go, so most music will have this noticeable change in density regardless of what format it is in.

Title: Re: Bitrate checkers
Post by: hiccup on March 13, 2022, 04:01:34 PM

Quote from: audiobabble on March 13, 2022, 02:43:20 PM

I'd have to disagree with that, surely the step in density is to do with what is happening in the music. It's very rare that you will find a track that starts at full volume from the get-go, so most music will have this noticeable change in density regardless of what format it is in.

Well, you are wrong.
Here is the same track as Opus encodes it:

(https://i.imgur.com/dsLTSaN.png)

The density bump at a specific frequency is a typical signature of mp3. (at least for Lame it is)

Title: Re: Bitrate checkers
Post by: BoraBora on March 16, 2022, 06:10:19 PM

Quote from: audiobabble on March 12, 2022, 09:58:25 PM

Ultimately, I prefer to trust my ears and can easily pick out a 320 mp3 next to a flac or wav file, although could be (and have been) fooled if all I'm hearing are 320 mp3's

It's almost impossible to hear differences between a properly encoded 320 kbps MP3 and its lossless version. You can occasionnaly identify such an MP3 by its pre-echo artefacts in some instruments like castanets, but not much else. I'm talking about a controlled double-blind test, like an ABX, which is the only test you can trust (for yourself or other people).

Even with golden ears and good training in spotting MP3 artefacts, there is no way you can "easily" pick out a 320 kbps from a lossless. So here are some leads:

* You're comparing two different editions with mastering differences
* One of these files has been converted from a sub-par version
* The two files have different sound levels (always use Replaygain before comparing)
* Placebo effect

Please don't feel insulted by the last one. Placebo effect is human and all of us are subject to it, without exception. ;)

As for verifying if a lossless album hasn't been converted, there's a very trustful way in most cases (not all): AccurateRip. This can be done on a complete ripped CD only (be it a single or a full album), but not lone tracks. Download and install CUETools: http://cue.tools/wiki/CUETools_Download#Download . In the Action box, check Verify. Then drag and drop your album folder (with or without a .cue) in the Input box and press Go. A log will be displayed in the main window. Set the options to your needs (writing the log in the album folder, recursive analysis etc.).

The log will give you results from both the CUETools and AccurateRip database. The most trustful is the AccurateRip one. Most logs will look like these ones (I edited them down to the important parts) :

Quote

[CUETools log; Date: 05/01/2016 00:16:18; Version: 2.1.6]
[AccurateRip ID: 000826fb-003728c0-71068c08] disk not present in database.

This is a CD-R home-produced by friends, never released to anyone but our circle. Obviously, it's missing from the AR database. But what if it was a commercial CD? Then you have to worry about the validity of this supposed lossless rip. No ID in the AR database can only happen if nobody ever ripped this CD in an AR-featured ripper (like MusicBee, obviously, but also Foobar2000, XLD, dBPowerAmp and lots of others). This doesn't mean this rip is not perfectly fine and 100% lossless but there's a doubt. If it's a well-known album, then it can be a transcoding or a counterfeited indonesian edition etc.

Quote

[CUETools log; Date: 16/01/2022 19:01:16; Version: 2.1.6]
Pregap length 00:00:33.

[AccurateRip ID: 0010e797-0092d206-89095a0b] found.
Track [ CRC | V2 ] Status
01 [d59f6fd8|19db8a5d] (0+0/3) No match
02 [19487148|207beb90] (0+0/3) No match
03 [084c706c|e2cad204] (0+0/3) No match
04 [8fcbba20|92e24646] (0+0/3) No match
05 [404bf14b|0638f188] (0+0/3) No match
06 [4a0c4d05|42e2884c] (0+0/3) No match
07 [d244f8bb|b25f4117] (0+0/3) No match
08 [7bc34679|e04ecb07] (0+0/3) No match
09 [1865b616|7e0e92ec] (0+0/3) No match
10 [bcf3ed5a|78e44ac6] (0+0/3) No match
11 [a221e222|ca0f5756] (0+0/3) No match
Offsetted by -6:
01 [8f5321ca] (0/3) No match (V2 was not tested)
02 [72840ea0] (0/3) No match (V2 was not tested)
03 [12bfccfc] (0/3) No match (V2 was not tested)
04 [c87b82f6] (0/3) No match (V2 was not tested)
05 [65fa96b5] (0/3) No match (V2 was not tested)
06 [67882f7b] (0/3) No match (V2 was not tested)
07 [cd0ae745] (0/3) No match (V2 was not tested)
08 [6c6cb3f9] (0/3) No match (V2 was not tested)
09 [29213c7e] (0/3) No match (V2 was not tested)
10 [6956ce94] (0/3) No match (V2 was not tested)
11 [ee6dbdca] (0/3) No match (V2 was not tested)

This CD has an AR ID with 3 copies registered but the rip doesn't match any of the 3. It may be suspicious or not, depending on the rarity/popularity of the CD. In this example, this is an obscure 1998 blues album from John Brim and Pinetop Perkins, released by an austrian label. One one hand, my copy could be from a reissue. Very small labels don't press huge quantities and they often repress on demand. On the other hand, Discogs lists only one edition of this CD. But maybe this rip hasn't been made in a secure ripper and isn't bit-perfect. It doesn't mean it's a transcoding but there is a doubt.

Quote

[CUETools log; Date: 13/01/2022 23:37:49; Version: 2.1.6]

[AccurateRip ID: 00148b2f-00dc767c-c309930e] found.
Track [ CRC | V2 ] Status
01 [a6af0a10|37d4a747] (10+23/36) Accurately ripped
02 [0e12503b|2000c2de] (10+23/36) Accurately ripped
03 [86b307e6|f913b7d7] (11+24/38) Accurately ripped
04 [e30a6e9f|ba7067a9] (10+24/37) Accurately ripped
05 [f4fceca6|88d1b62e] (10+24/37) Accurately ripped
06 [d75cf4cb|6dc314a1] (10+24/37) Accurately ripped
07 [9230d059|7c65d3f7] (10+24/37) Accurately ripped
08 [37ffdacb|76631d5e] (10+24/36) Accurately ripped
09 [104d2651|2c3e10e1] (10+24/37) Accurately ripped
10 [fae45614|934b713a] (10+24/37) Accurately ripped
11 [b1d3552e|1e6dc70f] (10+23/35) Accurately ripped
12 [d4bec96a|50446e9e] (10+23/36) Accurately ripped
13 [b995b13a|1223f04a] (10+24/37) Accurately ripped
14 [e4bb4c10|d5e5bf6a] (10+24/37) Accurately ripped
Offsetted by -1540:
01 [1915db1e] (03/36) Accurately ripped
02 [4f4b6e8a] (03/36) Accurately ripped
03 [c17095f8] (03/38) Accurately ripped
04 [7e01b51b] (03/37) Accurately ripped
05 [5ee22f08] (00/37) No match (V2 was not tested)
06 [b911904a] (03/37) Accurately ripped
07 [04fc996a] (03/37) Accurately ripped
08 [b8e8fa7d] (02/36) Accurately ripped
09 [de757d6a] (03/37) Accurately ripped
10 [7f47797d] (00/37) No match (V2 was not tested)
11 [fede457f] (02/35) Accurately ripped
12 [3aee5f85] (03/36) Accurately ripped
13 [85e9e706] (03/37) Accurately ripped
14 [566f4672] (03/37) Accurately ripped

This one is from the 1989 edition of The Complete Capitol Recordings, Vol. 1 of Art Tatum. No doubt here: this is the real deal. More than 30 people have ripped this CD and got the exact same CRC. You don't have to worry about a possible transcoding. This is the kind of log you'll see most of the times. Even 1 or 2 matches means you don't have to worry. No transcoded rip can match a logged lossless rip in the AR database.

Quote

[CUETools log; Date: 16/03/2022 17:44:38; Version: 2.1.6]
Padded some input files to a frame boundary.
[AccurateRip ID: 0046f85a-052d641a-7412071a] disk not present in database.

No doubt either with this one, but in a bad sense. The "Padded..." line means it's been transcoded. Not all transcodings can be identified by this padding, but if CUETools had to pad each track to a frame boundary, then you're 100% sure there was a transcoding in the chain.

As you can see, this CUETools verification isn't just about transcodings but also about bit-perfect rips, so it's inducing an additional level of paranoia and despair. ;D After all, is a non-transcoded but badly ripped CD still lossless? You also have to know some commercial CD can be mastered from MP3. They're rare but they exist, especially with labels reissuing public domain music. Lots of bad stuff here, soundwise. They don't have access to the tapes so they source their CD from whatever they find. But some well-established labels did this, too.

Again: it's rare, no need to worry much about it, just be aware of it. I have such a CD, a expanded reissue of an english 80's pop band, The Maisonettes. The label is Cherry Red, a perfectly legitimate english label, the music is copyrighted, and nonetheless the CD was mastered from MP3. Not a big deal, it's not a great album or a great band, I bought it for memories and I'm not even sure it would make a difference if it was mastered from tapes.