Skip to main content ↑ ↓

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: MP3 320 kbs vs Redbook ripped to WAV (Read 83815 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

MP3 320 kbs vs Redbook ripped to WAV

Reply #75 –
I also think the recording is okay. The spot is just low volume. Not so rare with Ravel: when testing Musepack recently it was the quiet starting part of Ravel's Bolero where I was able to ABX Musepack.
And with a longer part that low it's also quite common to turn up volume, because at home most people can't realize the dynamics of a concert hall.

So I think it's an interesting relevant sample.
And sure I'm curious about lame3100l --bCVBR 316's quality which should take good care of low volume spots.
lame3995o -Q1.7 --lowpass 17

MP3 320 kbs vs Redbook ripped to WAV

Reply #76 –
Quote from: UltimateMusicSnob on
This clip starts out extraordinarily low, but in the climaxes later on it reaches to its maximum mastered level of slightly over -6db (-5.7xx db, if I recall).

To be clear, and not to insinuate that you do, but turning the volume up to hear differences in detail for the quiet parts constitutes cheating in my book, unless you normally ride the volume while listening.

To me this is no different than cranking the gain on fade-outs and reverb tails in order to proclaim that 16 bits are insufficient as a delivery format.

Quote from: UltimateMusicSnob on
Is there some other sense in which this clip is badly recorded?

I don't find any other issues with the quality of the sample you provided.  That there's no annoying hum actually suggests to me the recording is pretty good, now that I know what kind of dynamic range it has.  It could make better use of 16 bits considering that the peak just makes use of the most significant bit.  This is assuming it was originally recorded as >16-bit digital.  If it's from analog tape then this last part about using more than 16 bits is not relevant.

MP3 320 kbs vs Redbook ripped to WAV

Reply #77 –
Quote from: greynol on
Quote from: UltimateMusicSnob on
This clip starts out extraordinarily low, but in the climaxes later on it reaches to its maximum mastered level of slightly over -6db (-5.7xx db, if I recall).

To be clear, and not to insinuate that you do, but turning the volume up to hear differences in detail for the quiet parts constitutes cheating in my book, unless you normally ride the volume while listening.

To me this is no different than cranking the gain on fade-outs and reverb tails in order to proclaim that 16 bits are insufficient as a delivery format.

Quote from: UltimateMusicSnob on
Is there some other sense in which this clip is badly recorded?

I don't find any other issues with the quality of the sample you provided.  That there's no annoying hum actually suggests to me the recording is pretty good, now that I know what kind of dynamic range it has.  It could make better use of 16 bits considering that the peak just makes use of the most significant bit.  This is assuming it was originally recorded as >16-bit digital.  If it's from analog tape then this last part about using more than 16 bits is not relevant.
The label says recorded in digital, and it's early (80s), so I would guess original capture was 16 bits, but I can't confirm directly.
I ride the volume all the time in the car, at home I don't ride much, but I do tend to run pretty loud overall, classical/rock/techno alike, max ~92 db measured at my nearfield position. Headphones have better isolation to start with so don't need to be so loud; I'm also paranoid about misjudging with headphones on, so I probably max a little less in the loudest parts, 88db or so.

I would say testing protocol specifics should be determined by the research question of interest. To improve the algorithm itself, as a developer I would care most about conditions typical of listeners--that's why I posted earlier that the tests posted here are of limited application. I have done cheap-earphones ABX tests before--might be interesting to repeat some trials that way. 

MP3 320 kbs vs Redbook ripped to WAV

Reply #78 –
Quote from: UltimateMusicSnob on
I ride the volume all the time in the car

I don't advise conducting ABX testing in the car under typical conditions, though I have a feeling you won't pass.

Not that you didn't already admit that.

MP3 320 kbs vs Redbook ripped to WAV

Reply #79 –
Okay, this is a replication under different playback hardware.
These are <$10 in-ear earphones. Apologies, but there's no brand name listed on them, so I don't know the make. Overall, I'd call them "dull" by comparison to my Beyerdynamics, and maybe weak in bass (no surprise), a little harsh on mids, not too bad.
Very good seal actually, so isolation is at least close to comparable.
Powered by on-the-motherboard audio chip for Dell Optiplex 780. Manual says it's "ADI 1984A High Definition Audio Codec - Integrated on System Board" ("Codec"???). Device Manager is even less forthcoming, just calls it "High Definition Audio Device".
This is with File 3, which was the originally requested LAME 3.99.5_vc6 encoder. 
Planned set of 12.

I have another requested encoding to do for 3100L, otherwise I think there's nothing more to be learned from this Ravel, unless someone has a point they want to pursue.

Code: [Select]
foo_abx 1.3.4 report
foobar2000 v1.2.8
2013/09/19 16:50:18

File A: E:\Ravel_Test_File_2_short.wav
File B: E:\Ravel_Test_File_3_short.mp3

16:50:18 : Test started.
16:50:48 : 01/01  50.0%
16:51:18 : 02/02  25.0%
16:51:28 : 02/03  50.0%
16:51:44 : 03/04  31.3%
16:52:00 : 04/05  18.8%
16:52:49 : 05/06  10.9%
16:53:09 : 06/07  6.3%
16:53:30 : 07/08  3.5%
16:54:30 : 08/09  2.0%
16:55:22 : 09/10  1.1%
16:56:52 : 10/11  0.6%
17:00:00 : 10/12  1.9%
17:00:08 : Test finished.

 ---------- 
Total: 10/12 (1.9%)

MP3 320 kbs vs Redbook ripped to WAV

Reply #80 –
One thing to mention related to some people always hear some defects with mp3 coding can have a simple hearing defect as reason. When mp3 was pretty new one of the first public listening test by c't magazine germany had one clear winner. The man was well trained but also had a hearing defect that made some filtering not working correctly om him.

Of course digging in the noisefloor for errors makes not much sense also like greynol already mentioned.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

MP3 320 kbs vs Redbook ripped to WAV

Reply #81 –
Quote from: Wombat on
One thing to mention related to some people always hear some defects with mp3 coding can have a simple hearing defect as reason. When mp3 was pretty new one of the first public listening test by c't magazine germany had one clear winner. The man was well trained but also had a hearing defect that made some filtering not working correctly om him.

Of course digging in the noisefloor for errors makes not much sense also like greynol already mentioned.
Interesting angle. Got a citation?

MP3 320 kbs vs Redbook ripped to WAV

Reply #83 –
Quote from: UltimateMusicSnob on
The comments I've seen about "lead sample" here and there give me this impression.

Quote from: greynol link=msg=0 date=
I have no idea what a "lead sample" is.


He's referring to lead voice, which I referred to earlier, and is perhaps the most annoying thing I've ever abx tested with.

MP3 320 kbs vs Redbook ripped to WAV

Reply #84 –
Okay, Ravel encoded in LAME 3100L using the recommended --bCVBR 316.
Planned set of 12 rounds.
Code: [Select]
foo_abx 1.3.4 report
foobar2000 v1.2.8
2013/09/20 00:36:46

File A: C:\Users\KiarkAudio\Documents\Ravel Listening Tests\Ravel_Test_File_2_short.wav
File B: C:\Users\KiarkAudio\Documents\Ravel Listening Tests\Ravel_Test_File_6.mp3

00:36:46 : Test started.
00:37:01 : 01/01  50.0%
00:37:13 : 02/02  25.0%
00:37:24 : 03/03  12.5%
00:37:49 : 03/04  31.3%
00:38:10 : 04/05  18.8%
00:38:29 : 05/06  10.9%
00:38:47 : 06/07  6.3%
00:39:16 : 07/08  3.5%
00:39:44 : 07/09  9.0%
00:40:22 : 08/10  5.5%
00:41:08 : 09/11  3.3%
00:43:59 : 10/12  1.9%
00:44:02 : Test finished.

 ---------- 
Total: 10/12 (1.9%)
I deliberately set out not to hunt for specific artifacts this time, but to decide on the basis of a gestalt. My cue here was "focus", meaning more for Redbook and a more diffuse sound for MP3. I would expect a similar sort of difference if I took an existing track and chorused and reverbed it just slightly. As an artifact, it's rather a pleasant one in terms of the aura of sound; the downside would be slightly less precision in the definition of separate instruments.
Of the encodings I've tried, this last one matches my taste preferences best. It seems to have frequency bands best balanced, among the MP3's.

MP3 320 kbs vs Redbook ripped to WAV

Reply #85 –
Quote from: Wombat on
German only, maybe some onlinetranslator will help.
http://www.heise.de/ct/artikel/Kreuzverhoertest-287592.html

Thanks for the cite, very interesting. Turns out my German (former life as a dramatic tenor--Florestan, Bacchus, Siegmund)  is still pretty good. If anyone's interested, the article reports a listening test subject with hearing damaged by an "explosion accident" which left him with a usable hearing range only up to 8 kHz, and tinnitus. So "bright" noises which in normal listeners would trigger the masking effects don't register with him, leaving the flanging artifacts of MP3 exposed. If I were studying psychoacoustics professionally, I would want to find out what this listener's responses reveal about audio processing---potentially very useful, in the same way that persons suffering from brain lesions in various regions shed valuable light on how the brain works.
  Last time I checked I still hear up to about 18 kHz, which represents the hearing loss more or less normal to aging.

MP3 320 kbs vs Redbook ripped to WAV

Reply #86 –
Quote from: UltimateMusicSnob on
Okay, Ravel encoded in LAME 3100L using the recommended --bCVBR 316.
Planned set of 12 rounds.

Thanks for posting.  I was curious how 3100l would do.  Looks like halb has some explaining to do.  Or, perhaps, tuning.   

MP3 320 kbs vs Redbook ripped to WAV

Reply #87 –
Quote from: UltimateMusicSnob on
Thanks for the cite, very interesting. Turns out my German (former life as a dramatic tenor--Florestan, Bacchus, Siegmund)  is still pretty good. If anyone's interested, the article reports a listening test subject with hearing damaged by an "explosion accident" which left him with a usable hearing range only up to 8 kHz, and tinnitus. So "bright" noises which in normal listeners would trigger the masking effects don't register with him, leaving the flanging artifacts of MP3 exposed. If I were studying psychoacoustics professionally, I would want to find out what this listener's responses reveal about audio processing---potentially very useful, in the same way that persons suffering from brain lesions in various regions shed valuable light on how the brain works.
  Last time I checked I still hear up to about 18 kHz, which represents the hearing loss more or less normal to aging.

I guess several people that have dips at one or more frequency bands will also be able to hear the masking not working properly. In the factory my father worked many people had a dip at some special frequency from the machines there running 24/7.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!
 

MP3 320 kbs vs Redbook ripped to WAV

Reply #88 –
Quote from: Wombat on
I guess several people that have dips at one or more frequency bands will also be able to hear the masking not working properly. In the factory my father worked many people had a dip at some special frequency from the machines there running 24/7.
Conceivably, but in that case it would depend on what frequency bands, of what width, and with what degree of hearing loss, interacting with what program material. The researcher would want to ask listeners with those hearing characteristics to listen for flanging effects. But unless someone knows of completed research in this area already, it's an unconfirmed hypothesis.
  Even with his extreme hearing loss, the man in the article had a hit rate of only 90%, and that was comparing 128 kbs MP3 (from an encoder written no later than March of 2000) to CD. I would ordinarily consider that a failure in ABX, since I use 95% as the threshold for significance, and prefer to go way beyond that.

MP3 320 kbs vs Redbook ripped to WAV

Reply #89 –
Quote from: gib on
Quote from: UltimateMusicSnob on
Okay, Ravel encoded in LAME 3100L using the recommended --bCVBR 316.
Planned set of 12 rounds.

Thanks for posting.  I was curious how 3100l would do.  Looks like halb has some explaining to do.  Or, perhaps, tuning. 
  I intended to give him at least some reason for celebrating. It's a very effective algorithm, and it does handle the low levels well, I thought.

MP3 320 kbs vs Redbook ripped to WAV

Reply #90 –
VBR sees low levels and thinks "I don't need to code this stuff, I can save some bits by not encoding it". CBR sees low levels and thinks "well, I've got to use these bits somewhere so I might as well encode this stuff". Difference is huge.


I'm oversimplifying. e.g. decent VBR will dynamically adjust absolute thresholds depending on signal level, because it knows one use case is turning the volume up to make low level stuff perfectly audible.


I don't know if this issue is just down to levels though. It would be trivial to boost the sample (at least the quiet part) before encoding to check.

EDIT: You've got to be very careful with such low levels.
ReplayGain = +17.81dB
Track peak = 0.077026

A simple truncation to 15-bits is audible...

foo_abx 1.3.3 report
foobar2000 v1.2.2
2013/09/20 15:08:07

File A: D:\audio\audio\codec testers\Ravel_Test_File_2_short.wav
File B: D:\audio\audio\codec testers\Ravel_Test_File_2_short 15-bit trunc.wav

15:08:07 : Test started.
15:08:59 : 01/01  50.0%
15:09:03 : 02/02  25.0%
15:09:10 : 03/03  12.5%
15:09:17 : 04/04  6.3%
15:09:24 : 05/05  3.1%
15:09:32 : 05/06  10.9%
15:09:43 : 06/07  6.3%
15:10:07 : 07/08  3.5%
15:10:10 : Test finished.

----------
Total: 7/8 (3.5%)

(dithering to 15-bits is even more audible)


EDIT2:

Oh blimey, even re-dithering to 16-bit is audible...

foo_abx 1.3.3 report
foobar2000 v1.2.2
2013/09/20 15:15:43

File A: D:\audio\audio\codec testers\Ravel_Test_File_2_short.wav
File B: D:\audio\audio\codec testers\Ravel_Test_File_2_short 16bit dither.wav

15:15:43 : Test started.
15:16:13 : 01/01  50.0%
15:16:22 : 02/02  25.0%
15:16:32 : 03/03  12.5%
15:16:38 : 03/04  31.3%
15:16:45 : 04/05  18.8%
15:16:50 : 05/06  10.9%
15:16:54 : 06/07  6.3%
15:17:05 : 07/08  3.5%
15:17:07 : Test finished.

----------
Total: 7/8 (3.5%)



Unless you're using a proper 24-bit mp3 decoder with 24-bit output, just the decoding could be enough to audibly alter this file if you listen at a very raised volume appropriate to make this very quiet part easily audible.

Boosting it by exactly 800% before encoding will at least remove this issue. I assume somewhere there's a peak above -18dB, so you can't actually do this for the whole track - but then I bet you can't listen at such a loud level for the whole track either.

ABXing quiet sections with the volume cranked up is kind of extreme.

Cheers,
David.

MP3 320 kbs vs Redbook ripped to WAV

Reply #91 –
Quote from: UltimateMusicSnob on
Okay, Ravel encoded in LAME 3100L using the recommended --bCVBR 316. ...(result: 7/8 after only 2.5 minutes)
...Of the encodings I've tried, this last one matches my taste preferences best. It seems to have frequency bands best balanced, among the MP3's.

Thanks for testing.
a) I'm happy to see that lame3100l --bCVBR 316 improves the situation a little bit and seems to be superior to CBR320.
b) I'm disappointed to see that ABXing seemed to be pretty easy for you also with this encoder and setting.

I've encoded the sample myself and looked whether there's something wrong with 3100l. Seems not to be the case: average bitrate is 318 kbps for the mp3packed file, so the constrained VBR method makes full use of the maximum data space possible also for this low volume snippet. Looking at the individual frames everything is as is expected, too: it's all long blocks with the exception of one frame at the very end, and they're all encoded with highest bitrate. Increase of SNR compared to plain -V0 is about 9 db for every frame.

Open question (if I haven't overlooked something): did you crank up the volume when ABXing compared to your usual listening level?
lame3995o -Q1.7 --lowpass 17

MP3 320 kbs vs Redbook ripped to WAV

Reply #92 –
Quote from: 2Bdecided on
[pointless full quote of giant post removed]
On the tests above, what were you listening for? Is this listening for a noise floor? If noise floor is just white noise, then the only thing to listen for is levels of noise, yes? A difference in how much white noise you hear below the music, when the volume is cranked way up? And of course, if not for the noise floor, then what is the audible cue?

MP3 320 kbs vs Redbook ripped to WAV

Reply #93 –
Quote from: halb27 on
Quote from: UltimateMusicSnob on
Okay, Ravel encoded in LAME 3100L using the recommended --bCVBR 316. ...(result: 7/8 after only 2.5 minutes)
...Of the encodings I've tried, this last one matches my taste preferences best. It seems to have frequency bands best balanced, among the MP3's.

Thanks for testing.
a) I'm happy to see that lame3100l --bCVBR 316 improves the situation a little bit and seems to be superior to CBR320.
b) I'm disappinted to see that ABXing seemed to be pretty easy for you also with this encoder and setting.

I've encoded the sample myself and looked whether there's something wrong with 3100l. Seems not to be the case: average bitrate is 318 kbps for the mp3packed file, so the constrained VBR method takes full use of the maximum data space possible also for this low volume snippet. Looking at the individual frames everything is as is expected, too: it's all long blocks with the exception of one frame at the very end, and they're all encoded with highest bitrate. Increase of SNR compared to plain -V0 is about 9 db for every frame.

Open question (if I haven't overlooked something): did you crank up the volume when ABXing compared to your usual listening level?
No, did not crank. I need to caution persons looking at the results--this was not easy. It requires very close mental focus, and a clear and well-defined notion of what to listen for. In this case I wanted to test non-artifact impressions strictly, so the notion was "focus". Turning up the volume makes that more difficult, not easier. This was hard, and the hardest part is keeping your mental ears' attention on the characteristics you're looking for. Especially because ABX trials are repetitions of the same clip, the mind tends to get, if not bored outright, then say "over-accustomed" to the sounds--they become too familiar, so attention wanders.
  This is a great encoder, as I say. My research question is "Is it possible at all?", and my conclusion would be at this point, Yes, it's possible, but you have to be kind of obsessive about close listening. 

MP3 320 kbs vs Redbook ripped to WAV

Reply #94 –
Quote from: UltimateMusicSnob on
On the tests above, what were you listening for? Is this listening for a noise floor? If noise floor is just white noise, then the only thing to listen for is levels of noise, yes? A difference in how much white noise you hear below the music, when the volume is cranked way up? And of course, if not for the noise floor, then what is the audible cue?

Yes, noise floor. The noise floor of the recording isn't quite white. With dither there's perfectly white noise added on top. Without dither (truncation) the added noise is quieter but fractionally less uniform. All fairly subtle though and very hard to detect without a reference.

Volume was cranked up, but I would happily listen to the full 30 second clip at that volume - it's not loud. I wouldn't dream of listening to anything else at anywhere near that volume though!

It's interesting that lossyWAV doesn't even touch the first 5 seconds of the file (it maintains the full 16-bits unchanged), and throughout the rest of the file it never knocks off more than 1-bit from the right channel.

Cheers,
David.

MP3 320 kbs vs Redbook ripped to WAV

Reply #95 –
Something this low in volume should compress extremely well, even without lossyWAV.

MP3 320 kbs vs Redbook ripped to WAV

Reply #97 –
Sorry, I should have made myself more clear.

2Bdecided commented on how lossyWAV needed to keep nearly every bit due to the low signal level. I was just pointing out that as far as lossless compression is concerned, you don't need lossyWAV anyway because the compression to lossless will be so efficient.

Sorry if this was too off topic.

MP3 320 kbs vs Redbook ripped to WAV

Reply #98 –
Oh, I get it now.

I think David often likes to use lossyWAV as a tool to determine how many LSBs can be tossed without affecting audibility, based on a setting that hasn't yet been shown not to be transparent?

MP3 320 kbs vs Redbook ripped to WAV

Reply #99 –
I might have suggested that the OP try to ABX the lossyWAV version, but clearly that would be a waste of time in this case.