Helpful ReplySample rate conversion question.

Page: < 123 > Showing page 2 of 3
Author
The Maillard Reaction
Max Output Level: 0 dBFS
  • Total Posts : 31918
  • Joined: 2004/07/09 20:02:20
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 08:54:14 (permalink)
bapu


bitflipper
However, a null test wouldn't be the best way to check timing. The notes (or, more accurately the several thousand samples that make up the initial transient and therefore the onset of the note) are going to be in exactly the same place regardless of whether the two files null. 

And so it may be said that the transient timing of the converted wav will always be as accurate (in time) as it was recorded?


I think it's more correct to say that the results of the converted wave will always be more accurate than the performance.

Issues like monitor latency and latency compensation will introduce much larger variances in timing that the performer may interpret as a shift from their intention or recollection of how they played.


best regards,
mike





#31
bobguitkillerleft
Max Output Level: -72 dBFS
  • Total Posts : 944
  • Joined: 2011/05/17 17:28:58
  • Location: Adelaide Australia
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 09:38:01 (permalink)
No Questions No Answers So Sorry.  
post edited by bobguitkillerleft - 2012/04/03 22:15:09
#32
drewfx1
Max Output Level: -9.5 dBFS
  • Total Posts : 6585
  • Joined: 2008/08/04 16:19:11
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 12:35:52 (permalink)
bapu


bitflipper
However, a null test wouldn't be the best way to check timing. The notes (or, more accurately the several thousand samples that make up the initial transient and therefore the onset of the note) are going to be in exactly the same place regardless of whether the two files null. 

And so it may be said that the transient timing of the converted wav will always be as accurate (in time) as it was recorded?

Technically with Sonar's SRC, it shouldn't be off by more than a ridiculously small amount which is many orders of magnitude below what humans can perceive. Moving your head less than a billionth of an inch closer/further from the speaker will produce a greater change in timing.

IOW, from your perspective it should be 100% perfect. 

 In order, then, to discover the limit of deepest tones, it is necessary not only to produce very violent agitations in the air but to give these the form of simple pendular vibrations. - Hermann von Helmholtz, predicting the role of the electric bassist in 1877.
#33
bapu
Max Output Level: 0 dBFS
  • Total Posts : 86000
  • Joined: 2006/11/25 21:23:28
  • Location: Thousand Oaks, CA
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 12:42:28 (permalink)
mike_mccue

Issues like monitor latency and latency compensation will introduce much larger variances in timing that the performer may interpret as a shift from their intention or recollection of how they played. 



Please define "much larger variances".


Are you saying that a listen on different monitors will perceive a timing shift for me?

Are you also saying that certain plugs, or combination of plugs, will issue me a perceived timings shift over the raw wav?


Are both of these examples still in the minute sub-sample category as posited in above posts?




#34
John
Forum Host
  • Total Posts : 30467
  • Joined: 2003/11/06 11:53:17
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 12:54:24 (permalink)
bapu


mike_mccue

Issues like monitor latency and latency compensation will introduce much larger variances in timing that the performer may interpret as a shift from their intention or recollection of how they played. 



Please define "much larger variances".


Are you saying that a listen on different monitors will perceive a timing shift for me?

Are you also saying that certain plugs, or combination of plugs, will issue me a perceived timings shift over the raw wav?


Are both of these examples still in the minute sub-sample category as posited in above posts?


Bapu I think Mike means phase differences due to driver placement in a speakers box. With near fields its an issue. Not one anyone has to worry about though.

Best
John
#35
drewfx1
Max Output Level: -9.5 dBFS
  • Total Posts : 6585
  • Joined: 2008/08/04 16:19:11
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 13:07:26 (permalink)
bapu


Are you also saying that certain plugs, or combination of plugs, will issue me a perceived timings shift over the raw wav?
I suppose you could argue that using a non-linear-phase eq will cause varying degrees of phase shift (with the most near the cutoff frequency). But there is some debate about whether this kind of phase shift is perceptible at all. And if it is, how much phase shift is necessary before it's audible at a given frequency. 

But I wouldn't worry about it. Keep in mind that at 10kHz, 180 degrees (half a cycle) of phase shift only equals .05ms.

 In order, then, to discover the limit of deepest tones, it is necessary not only to produce very violent agitations in the air but to give these the form of simple pendular vibrations. - Hermann von Helmholtz, predicting the role of the electric bassist in 1877.
#36
Jonbouy
Max Output Level: 0 dBFS
  • Total Posts : 22562
  • Joined: 2008/04/14 13:47:39
  • Location: England's Sunshine South Coast
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 13:17:14 (permalink)
I like the fact that we keep telling him not to worry about it and then give him a little bit more information...

This idea should keep his posting rate down from 48,000 per second to 44,100, no?

"We can't do anything to change the world until capitalism crumbles.
In the meantime we should all go shopping to console ourselves" - Banksy
#37
drewfx1
Max Output Level: -9.5 dBFS
  • Total Posts : 6585
  • Joined: 2008/08/04 16:19:11
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 13:22:04 (permalink)
I like feeding hypochondriacs new things to worry about!

 In order, then, to discover the limit of deepest tones, it is necessary not only to produce very violent agitations in the air but to give these the form of simple pendular vibrations. - Hermann von Helmholtz, predicting the role of the electric bassist in 1877.
#38
Jonbouy
Max Output Level: 0 dBFS
  • Total Posts : 22562
  • Joined: 2008/04/14 13:47:39
  • Location: England's Sunshine South Coast
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 13:26:26 (permalink)
drewfx1


I like feeding hypochondriacs new things to worry about!


That makes me sick...

"We can't do anything to change the world until capitalism crumbles.
In the meantime we should all go shopping to console ourselves" - Banksy
#39
drewfx1
Max Output Level: -9.5 dBFS
  • Total Posts : 6585
  • Joined: 2008/08/04 16:19:11
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 13:28:28 (permalink)
Be careful! I've heard sickness can screw up your timing! 

 In order, then, to discover the limit of deepest tones, it is necessary not only to produce very violent agitations in the air but to give these the form of simple pendular vibrations. - Hermann von Helmholtz, predicting the role of the electric bassist in 1877.
#40
trimph1
Max Output Level: -12 dBFS
  • Total Posts : 6348
  • Joined: 2010/09/07 19:20:06
  • Location: London ON
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 15:00:06 (permalink)
drewfx1


Be careful! I've heard sickness can screw up your timing! 

Maybe that explains my timing....

The space you have will always be exceeded in direct proportion to the amount of stuff you have...Thornton's Postulate.

Bushpianos
#41
Karyn
Ma-Ma
  • Total Posts : 9200
  • Joined: 2009/01/30 08:03:10
  • Location: Lincoln, England.
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 18:48:02 (permalink)
bitflipper


Just to be clear: neither sample rate nor sample rate conversion affects timing. Every note will still be exactly Am, just as you played it.
Coffee hosed
 
 
 
 
 
 
 
 
 
 
 
Sorry


Mekashi Futo
Get 10% off all Waves plugins.
Current DAW.  i7-950, Gigabyte EX58-UD5, 12Gb RAM, 1Tb SSD, 2x2Tb HDD, nVidia GTX 260, Antec 1000W psu, Win7 64bit, Studio 192, Digimax FS, KRK RP8G2, Sonar Platinum

#42
Jonbouy
Max Output Level: 0 dBFS
  • Total Posts : 22562
  • Joined: 2008/04/14 13:47:39
  • Location: England's Sunshine South Coast
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 18:56:13 (permalink)
Karyn


bitflipper


Just to be clear: neither sample rate nor sample rate conversion affects timing. Every note will still be exactly Am, just as you played it.
Coffee hosed
 
 
 
 
 
 
 
 
 
 
 
Sorry


You should be sorry, he can't claim the sample rate conversion was the cause of him being out of tune now.

See what you did?

Besides if you'd have just told him he'd be OK in the first reply I'm sure this thread wouldn't have ended up being a 2 pager....

"We can't do anything to change the world until capitalism crumbles.
In the meantime we should all go shopping to console ourselves" - Banksy
#43
Karyn
Ma-Ma
  • Total Posts : 9200
  • Joined: 2009/01/30 08:03:10
  • Location: Lincoln, England.
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 19:00:48 (permalink)
Hey,  I wasn't the one that mentioned aliasing and sub-sampling...

Mekashi Futo
Get 10% off all Waves plugins.
Current DAW.  i7-950, Gigabyte EX58-UD5, 12Gb RAM, 1Tb SSD, 2x2Tb HDD, nVidia GTX 260, Antec 1000W psu, Win7 64bit, Studio 192, Digimax FS, KRK RP8G2, Sonar Platinum

#44
Jonbouy
Max Output Level: 0 dBFS
  • Total Posts : 22562
  • Joined: 2008/04/14 13:47:39
  • Location: England's Sunshine South Coast
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 19:02:33 (permalink)
Karyn


Hey,  I wasn't the one that mentioned aliasing and sub-sampling...


True dat.

"We can't do anything to change the world until capitalism crumbles.
In the meantime we should all go shopping to console ourselves" - Banksy
#45
The Maillard Reaction
Max Output Level: 0 dBFS
  • Total Posts : 31918
  • Joined: 2004/07/09 20:02:20
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 19:35:50 (permalink)
bapu


mike_mccue

Issues like monitor latency and latency compensation will introduce much larger variances in timing that the performer may interpret as a shift from their intention or recollection of how they played. 



Please define "much larger variances".


Are you saying that a listen on different monitors will perceive a timing shift for me?

Are you also saying that certain plugs, or combination of plugs, will issue me a perceived timings shift over the raw wav?


Are both of these examples still in the minute sub-sample category as posited in above posts?



8-)
Dude, I think you need to talk to an audio scientist about this.
8-)






#46
bapu
Max Output Level: 0 dBFS
  • Total Posts : 86000
  • Joined: 2006/11/25 21:23:28
  • Location: Thousand Oaks, CA
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 20:05:22 (permalink)
John


bapu


mike_mccue

Issues like monitor latency and latency compensation will introduce much larger variances in timing that the performer may interpret as a shift from their intention or recollection of how they played. 



Please define "much larger variances".


Are you saying that a listen on different monitors will perceive a timing shift for me?

Are you also saying that certain plugs, or combination of plugs, will issue me a perceived timings shift over the raw wav?


Are both of these examples still in the minute sub-sample category as posited in above posts?


Bapu I think Mike means phase differences due to driver placement in a speakers box. With near fields its an issue. Not one anyone has to worry about though.

Thanks John.
mike_mccue


8-)
Dude, I think you need to talk to an audio scientist about this.
8-)

N/A now.
#47
Crg
Max Output Level: 0 dBFS
  • Total Posts : 7719
  • Joined: 2007/11/15 07:59:17
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 20:16:01 (permalink)
Interesting thread. I have ask though, which is speculation, at what perceptual level of resolution do we hear a timing inacuracy? I'm sure it's different for every set of ears. Every quarter note snare hit entered by a live player is going to have some color of the performance as it moves and as such will have it's own small timing and expression-therfore number of samples used-recorded within a one second period. At some point you're bound to have a moving event that doesn't really adhere to timeclock regimen that you will have to move slightly to restore the feel of the peice. I might not notice it, you might not notice it, but based on a concept of sample alignment-position to create a feel it might not be exactly the same. Do we feel that deep? Do we hear that deep?

Craig DuBuc
#48
bobguitkillerleft
Max Output Level: -72 dBFS
  • Total Posts : 944
  • Joined: 2011/05/17 17:28:58
  • Location: Adelaide Australia
  • Status: offline
Re:Sample rate conversion question. 2012/04/01 21:05:06 (permalink)



Kumbh Mela
oh the Humanity 
post edited by bobguitkillerleft - 2012/04/03 09:31:53
#49
bobguitkillerleft
Max Output Level: -72 dBFS
  • Total Posts : 944
  • Joined: 2011/05/17 17:28:58
  • Location: Adelaide Australia
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 00:36:59 (permalink)
#50
Danny Danzi
Moderator
  • Total Posts : 5810
  • Joined: 2006/10/05 13:42:39
  • Location: DanziLand, NJ
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 04:42:55 (permalink)
bapu


And, unless you're Danny Danzi or Jimmy Iovine (in his youth), none of us will ever hear a real timing issue between a converted 24/48 to 24/44.1 track. 



LOL! I think you may be giving me a bit too much credit, but thanks for that. :) I don't think I can tell a difference on this...but then again, it's never been something I've ever tried to listen for. I have noticed a few little anomalies that may or may not be because of this. To be honest, it's both a blessing and a curse to be able to hear some of this stuff. A blessing because it's great to be able to hear things and fix them or notice problems, and a curse because sometimes, as Drew points out, there ARE cases when you think you hear something and it's just a false alarm. Also, when you don't know this stuff exists and then someone brings it to your attention, then you ARE listening for it and sometimes...well, again, you can think you hear it when in reality you probably don't.
 
If it's off by what Karyn, Noel and Drew mentioned....I seriously doubt I could hear it. However, it's worth me testing for the simple fact that I have heard a few things in the past as I've mentioned. In a few instances of me being so smashed with work, I've recorded a few things for people at 24/48 when they weren't using that bit/sample rate in their projects. There would be a few slight timing issues once they brought my stuff into their projects to where I'd have to show them where they needed to align something.
 
I always thought this was due to how some soundcards talk to others...but when you have a tempo map and are operating out of the same project template as someone else and then you send them a broadcast wave, it should be in sync. I've noticed at times that this is not always the case. Could it be I'm literally hearing this imperfection? Personally, I'd say I'm not and it's a soundcard issue between my stuff and whoever I'm working with. Let me ask this...can any of you literally hear this or is it something that you know in your mind is off a bit that may make you think you can hear it?
 
I never even knew there would be a timing difference so it's not something I've ever considered or tried to listen for. But you better believe I'm going to now. I still don't think I'll be able to tell as it's never been something that has stuck out to me in my own realm using my gear. I've done this several times and have never had a problem here. But like I say, I did notice some weird timing type things after I've given clients wave files that were different than what they were using. I still chalk it up as a soundcard communication though. There's no way I'm hearing 44 thousandth of a second. If I am, I seriously need help. LOL!
 
-Danny


My Site
Fractal Audio Endorsed Artist & Beta Tester
#51
Jonbouy
Max Output Level: 0 dBFS
  • Total Posts : 22562
  • Joined: 2008/04/14 13:47:39
  • Location: England's Sunshine South Coast
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 06:19:45 (permalink)
Danny I think it is in the realms of possibility that because of how certain Sample Rate Converters have been implemented in the past there have been noticeable artifacts as a result.  As Noel says SRC has come a long way.  And you may be right that stems produced outside of your own supervision may indeed cause some notable weirdness because of this process taking place using bad SRC processes.

Being as Ed is doing the conversion here within Sonar from Alex's (I'm presuming) modern setup the likelyhood of something dodgy happening are as slim as (1/44,100) - (1/48,000)...at a guess.

As we all know the during the difference translating between theory and reality stuff happens and we don't always find out what caused it which can lead to some strange beliefs for all of us.

"We can't do anything to change the world until capitalism crumbles.
In the meantime we should all go shopping to console ourselves" - Banksy
#52
Karyn
Ma-Ma
  • Total Posts : 9200
  • Joined: 2009/01/30 08:03:10
  • Location: Lincoln, England.
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 08:31:53 (permalink)
The width of a transient like a drum hit or the start of a guitar note is many samples wide.  The absolute worse case would be a very high frequency percussive hit (like the crackles you get from a vinyl record) but even these are several samples wide.

Why might any of this matter?  Well the time between samples at 48k is smaller than the time between samples at 44.1k and thus running the two side by side (if you could) would mean that individual samples would rarely match perfectly in absolute time.

As the op asked for specific evidence,  assuming sample 1 of each starts at time 0:0  (m:s)

S(1)44.1 = 0:0    S(442))44.1 = 0:0.01
 
S(1)48   = 0:0     S(481)48    = 0:0.01
 
Thus, each 1/100th of a second the samples will align perfectly in time,  whereas between these points the samples will never match the same absolute time.
 
So for a total worse case with a single sample "spike" in the 48k stream, that sample will most likely not align perfectly in time with the corresponding sample at 44.1k,  BUT the most  the error can be is half the sample width at the target sample rate,  ie: 1/(44100 *2) = 0.00001134 Seconds early or late.
 
 
 
 
 
 
 
Why does the track I recieved from a colab partner not sync with my master track?
 
Drift in master clocks between two (or more) seperate systems.  This is why you have to sync digital equipment with a common clock (word clock) as free running clocks in seperate pieces of equipment will never run at the same speed.
 
If you send a .wav to someone to play along to, you've effectivly sent them a timing map of your master clock at the time you first recorded it. As long as they play along to that wav, their recording will match your timing and their resultant .wav will sync on your system to your master.
 
But, if you tell them "Give me 3 minutes of keyboards in Am at 132bpm" and they send you a .wav there's a good chance that by the end of 3 minutes it will be out of sync.
 
This has nothing to do with SRC.

Mekashi Futo
Get 10% off all Waves plugins.
Current DAW.  i7-950, Gigabyte EX58-UD5, 12Gb RAM, 1Tb SSD, 2x2Tb HDD, nVidia GTX 260, Antec 1000W psu, Win7 64bit, Studio 192, Digimax FS, KRK RP8G2, Sonar Platinum

#53
The Maillard Reaction
Max Output Level: 0 dBFS
  • Total Posts : 31918
  • Joined: 2004/07/09 20:02:20
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 08:42:35 (permalink)

I think this was Bapu's April Fools thread, but just in case, here's something I read a couple years ago that seemed easy to understand:



from: http://www.voxengo.com/product/r8brainpro/

r8brain PRO is a professional sample rate converter designed to deliver an unprecedented sample rate conversion (SRC) quality.  Unlike many existing SRC algorithms available on the market, r8brain PRO implements sample rate conversion processing in its full: interpolation and decimation steps without exploiting any kind of simplifications; the signal is first resampled to a least common multiple sample rate which makes conversion perfect.  In the core of the SRC algorithm, we use the convolution methods of our Pristine Space convolution processor which is known for its highly precise convolution processing.  This gives us high sample rate conversion quality in combination with comparably small processing times: sample rate conversion without compromises!

Like many existing SRC programs, r8brain PRO offers you a linear-phase conversion mode.  But more importantly, you also have an option of using the minimum-phase conversion mode, which finally brings SRC with true analog qualities to affordable digital audio workstations: in this mode, r8brain PRO works like an ideal digital-to-analog converter followed by an analog-to-digital converter to resample the audio.  This eliminates pre-ringing associated with linear-phase designs, while introducing only a minimal amount of phase coloration.

r8brain PRO can read mono, stereo and multi-channel files in both WAV and AIFF file formats, creating 16-, 24- and 32-bit mono, stereo and multi-channel WAV files in fixed and floating point formats.  EBU BWF (broadcasting) extensions, extensible wave format, sample loops and textual data residing inside the file are also supported.  For the sake of convenience, r8brain PRO allows you to perform batch conversions in a convenient manner.

r8brain PRO's bit-depth conversion is limited to flat dithering.  We have decided not to implement noise-shaping dithering because pro audio production software available on the market usually offers the user noise-shaping dithering of some kind already.  We also based our decision on the fact that the sample rate conversion process often adjusts peak structure of the original program material, thus, in many cases, making a subsequent peak-limiting a necessity.  To prevent output audio from clipping we have implemented a level normalization feature.



#54
The Maillard Reaction
Max Output Level: 0 dBFS
  • Total Posts : 31918
  • Joined: 2004/07/09 20:02:20
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 08:52:29 (permalink)

Here is a website that claims to have collected SRC data from more apps than I can count:

http://src.infinitewave.ca/

I selected the "sweep" analysis and compared R8brain Pro, Minimum Phase to SONAR 8.5.

The results seem to close, but there seems to be enough difference to encourage curiosity.


best regards,
mike


#55
Karyn
Ma-Ma
  • Total Posts : 9200
  • Joined: 2009/01/30 08:03:10
  • Location: Lincoln, England.
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 08:57:22 (permalink)
mike_mccue


The results seem to close, but there seems to be enough difference to encourage curiosity.

I might be a nerd, but I'm not that much of a nerd... 


Mekashi Futo
Get 10% off all Waves plugins.
Current DAW.  i7-950, Gigabyte EX58-UD5, 12Gb RAM, 1Tb SSD, 2x2Tb HDD, nVidia GTX 260, Antec 1000W psu, Win7 64bit, Studio 192, Digimax FS, KRK RP8G2, Sonar Platinum

#56
The Maillard Reaction
Max Output Level: 0 dBFS
  • Total Posts : 31918
  • Joined: 2004/07/09 20:02:20
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 09:02:58 (permalink)

;-)

Hey, at least you knew I wasn't writing about voice coil alignment or crossover compromises.

;-)


#57
Karyn
Ma-Ma
  • Total Posts : 9200
  • Joined: 2009/01/30 08:03:10
  • Location: Lincoln, England.
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 09:13:39 (permalink)
My coil alignment is fine, thank you

Mekashi Futo
Get 10% off all Waves plugins.
Current DAW.  i7-950, Gigabyte EX58-UD5, 12Gb RAM, 1Tb SSD, 2x2Tb HDD, nVidia GTX 260, Antec 1000W psu, Win7 64bit, Studio 192, Digimax FS, KRK RP8G2, Sonar Platinum

#58
The Maillard Reaction
Max Output Level: 0 dBFS
  • Total Posts : 31918
  • Joined: 2004/07/09 20:02:20
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 09:26:56 (permalink)

It is just Tannoy bapu.


#59
bapu
Max Output Level: 0 dBFS
  • Total Posts : 86000
  • Joined: 2006/11/25 21:23:28
  • Location: Thousand Oaks, CA
  • Status: offline
Re:Sample rate conversion question. 2012/04/02 11:03:43 (permalink)
Hey everyone,

No, this was not an April fools thread. It was a serious question.

To put it simply, say a person records 4 simple quarter notes starting at measure two (with muted audio for measure one) @ 24/48 at a fixed tempo. For arguments sake, say the quarter notes are dead on.

That person sends me a WAV of those two measures (@24/48). My project is exactly two measures @ the same fixed tempo, but my project is 24/44.1. 

We all know and accept that SOANR wil convert the 24/48 to 24/44.1. 

The intent of the question was; will the quarter notes still be dead on (from an "ears" point of view) or is it possible they can shift by a 64th note during the conversion?

It seems, by the answers here, the mathematical answer is no, not that much. It seems the answer is that it may shift by something like ~1/44.1K of a second. But the underlying principal to me seems to me that if measure two starts at a specific point in time any two modern high quality sound cards, they would "pretty much" be at that same point in time. I can appreciate the difference in manufacturers but we are probably not even in the realm of 1/128th note difference are we?
#60
Page: < 123 > Showing page 2 of 3
Jump to:
© 2025 APG vNext Commercial Version 5.1