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Offline mhibbs

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #75 on: November 07, 2005, 11:12:25 AM »
Cool...I'll try that then.  Interestingly it seems that Wavelab creates a SBE on every file it saves...at least that's been my experience.  Is there a way to fix that?
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Re: Dither/resampling/temp file tests in Wavelab
« Reply #76 on: November 07, 2005, 12:24:06 PM »
Mitch, maybe drop a CD start marker at the beginning of the file and a CD stop marker at the end, then do an auto-split.

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #77 on: November 07, 2005, 10:13:02 PM »
Well, being the geek that I also am, I came home and ran some similar tests.  I'll only explain the one I found most interesting, which I think throws a bit of a kink in Damon's findings.  Here's what I did.

1.  took a 24/96 source file (source.wav)
2.  dithered source.wav using Wavelab uv22hr and "save as new file" called it (dith_test1.wav)
3.  closed everything, then re-opened source.wav
4.  dithered source.wav using Wavelab uv22hr and "save as new file" called it (dith_test2.wav)
5.  opened dith_test1.wav and dith_test2.wav in Wavelab and used Analysis>Audio File Comparer to compare
RESULT:  The two files are identical. 
NEXT>>
6.  opened dith_test1.wav in Wavelab and resampled to 44.1 and "save as new file" called it (dith_resamp_test1.wav)
7.  opened dith_test2.wav in Wavelab and resampled to 44.1 and "save as new file" called it (dith_resamp_test2.wav)
8.  opened dith_resamp_test1.wav and dith_resamp_test2.wav in Wavelab and used Analysis>Audio File Comparer to compare
RESULT:  The two files are NOT IDENTICAL

From what I can tell, Wavelab does not identically resample the same file.  Every time you run it against a source file, save as a new file, then compare the outputs, you'll find differences.  The fact that this is the case makes it impossible to do a comparison where resampling is involved.

Moving on to a batch dither comparison on it's own.

1.  took track1.wav and track2.wav (24/96 tracks) and combined them in Wavelab and called it combine.wav
2.  dithered combine.wav in Wavelab using uv22hr and "save as new file" and called it combine_dith.wav
3.  used Wavelab batch process and uv22hr to dither track1.wav and track2.wav and "save as new file" and called them track1_dith.wav and track2_dith.wav
4.  used Wavelab to combine track1_dith.wav and track2_dith.wav and saved the new file calling it separate_dith.wav
5.  opened combine_dith.wav and separate_dith.wav in Wavelab and used Analysis>Audio File Comparer to compare
RESULT:  The two files are NOT IDENTICAL

Hmm.  Seems that applying the uv22hr dither algorithm to one big file vs. two small files does yeild different results when the two files are combined.  I had the Wavelab compare process create a delta file with markers.  Visually, it appears to be a flat line.  Listening to it yeilds dead silence.  Viewing it on the FFT meter shows noise at aprox -140db across the frequency range. 

What does this tell us?  Somethign to debate, but my inital thoughts are simply that the complicated math problem that is dither doesn't yeild identical results when the source files are different...which they fundamentally are (in a bits and bytes sort of way) in this situation.  To me, the more I think about it, that seems to make some logical sense.  Does it really matter or mean anything?  I could argue not, b/c there really is no basis for comparison.  Whether you do it in batch or as one file, you are processing the file and altering it resulting in a file that IS different from the 24/96 source.  True, they are different relative to each other, but both are different relative to the original source.

Moving on to the issue w/ the .wav not lining up when combined.  Personally I don't see it...mine appear to join fine when viewed at the smallest zoom possible in Wavelab.  Am I missing something here????  I very well may not know what I'm looking for.

And finally, the SBEs.  I didn't have to test it, b/c I know it to be true.  24/96 files dithered and resampled result in files w/ SBE's.  HOWEVER, I believe the issue resides in Wavelab itself, NOT the fact that this processing is done in batch.  In my experience, every 16/44.1 file saved in Wavelab has a SBE b/c by default Wavelab doesn't save the file on a CD defined sector boundry.  CDWav does, which is why we all use it to cut tracks.  As a result, the comparison we're talking about relative to SBEs is really a comparison of how Wavelab and CDWav save 16/44.1 files.  True, they are different, and Wavelab does screw it up.  I got an interesting PM about how to address this issue...

---------
markers.....make sure you do CD track start, CD Track splice markers(for the individual tracks) and cd track end...make sure you check "quantize to CD Frame" THEN do an autosplit.no more SBEs!

Teddy
---------

Doesn't seem possible to work Teddy's process into this since the files are already split.  The only way to really address the SBEs is w/ shntool fix.  It's essentially the same thing though, since it just adjusts the split relative to the next file from the first SBE to the last and pads the final file. 

So there you have it.  Feel free to shoot holes in my theory/testing, but it appears to me this is 6 one way, 1/2 a dozen the other unless there is more to the wavs not lining up when re-joined.  Which I agree in theory certainly seems possible if the dither/resample process alters the end of the first wav and the beginning of the second wav differently.  Any difference would seem to be way down at -140db and not audible.  But again, I didn't see it, and would love to see a pic of an example if Damon or someone else can grab one. 

Finally, and I'll shut up now.  After all of this, I would agree that the process Nick outlined makes the most sense and seems the "safest" and that is what I'll be doing from now on although I find this all very interesting from a  purely "academic" perspective.


Damon, guess we can be dork buddies.



mitch

« Last Edit: November 07, 2005, 10:18:55 PM by mhibbs »
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Offline MattD

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #78 on: November 07, 2005, 10:26:55 PM »
1.  took a 24/96 source file (source.wav)
2.  dithered source.wav using Wavelab uv22hr and "save as new file" called it (dith_test1.wav)
3.  closed everything, then re-opened source.wav
4.  dithered source.wav using Wavelab uv22hr and "save as new file" called it (dith_test2.wav)
5.  opened dith_test1.wav and dith_test2.wav in Wavelab and used Analysis>Audio File Comparer to compare
RESULT:  The two files are identical. 

This result is surprising to me. Dithering should add random or shaped random noise to the audio (I know, pseudo-random in this case), and should be practically impossible to duplicate.
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Re: Dither/resampling/temp file tests in Wavelab
« Reply #79 on: November 08, 2005, 02:03:36 AM »
1.  took a 24/96 source file (source.wav)
2.  dithered source.wav using Wavelab uv22hr and "save as new file" called it (dith_test1.wav)
3.  closed everything, then re-opened source.wav
4.  dithered source.wav using Wavelab uv22hr and "save as new file" called it (dith_test2.wav)
5.  opened dith_test1.wav and dith_test2.wav in Wavelab and used Analysis>Audio File Comparer to compare
RESULT:  The two files are identical.

This result is surprising to me. Dithering should add random or shaped random noise to the audio (I know, pseudo-random in this case), and should be practically impossible to duplicate.

Likewise.  I performed a similar test with a couple different apps and dither/noise shaping algos:

Master File Format    :  24-bit, 44.1 kHz master file
Target File Format    :  16-bit, 44.1 kHz (no resample)
Application           :  Wavelab 5.00a (WL)
Application           :  Adobe Audition 1.5 (AA)
Application           :  Exact Audio Copy 0.95pb4 Wave Compare (EAC)
Dither / Noise Shaping:  AA Internal
Dither / Noise Shaping:  WL Internal
Dither / Noise Shaping:  WL UV22HR
Dither / Noise Shaping:  iZotope Ozone 3 MBIT+ (in both AA and WL)
Dither / Noise Shaping:  Steinberg Waves L2/IDR (in both AA and WL, *no* compresson - only dither/ns)

For each app/dither/noise shaping combination, I generated two separate 16-bit / 44.1 kHz target files from the same master file, and then compared those two target files against one another with EAC.. 

===============================
APP - DITHER - NS | RESULT
===============================
WL  - UV22HR - NA | IDENTICAL
WL  - L2/IDR - Y  | DIFFERENT
WL  - MBIT+  - Y  | DIFFERENT
WL  - INTERN - Y  | IDENTICAL
WL  - L2/IDR - N  | DIFFERENT
WL  - MBIT+  - N  | DIFFERENT
WL  - INTERN - N  | IDENTICAL
-------------------------------
AA  - L2/IDR - Y  | IDENTICAL
AA  - MBIT+  - Y  | DIFFERENT
AA  - INTERN - Y  | DIFFERENT
AA  - L2/IDR - N  | IDENTICAL
AA  - MBIT+  - N  | DIFFERENT
AA  - INTERN - N  | DIFFERENT


NOTES

[1]  The results suggest to me that the pseudo-random algos in UV22HR and WL Internal dither are not very, well...random.  Does it matter?  Dunno.

[2]  Why the very same Waves L2/IDR dither and noise shaping plug-in generates different files in Wavelab (suggesting a pseudo-random algo) and not in Adobe Audition (suggesting a non-pseudo random algo) has me stumped.  I haven't the foggiest idea what to make of this one.

[3]  Note that while the target files generated using Adobe Audition using L2/IDR *without* noise shaping are identical to one another, these target files are NOT identical to the files generated with the same application / plugin *with* noise shaping.
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Re: Dither/resampling/temp file tests in Wavelab
« Reply #80 on: June 14, 2006, 04:47:30 PM »
ok, since reading this, ive been taping for many years and have never used cue sheets, what the hell are they and what do they do? and how do you make them in cdwave ???
Schoeps MK 4V & MK 41V ->
Schoeps 250|0 KCY's (x2) ->
Naiant +60v|Low Noise PFA's (x2) ->
DarkTrain Right Angle Stubby XLR's (x3) ->
Sound Devices MixPre-6 & MixPre-3

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline F.O.Bean

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #81 on: June 14, 2006, 04:53:46 PM »
ok, since reading this, ive been taping for many years and have never used cue sheets, what the hell are they and what do they do? and how do you make them in cdwave ???
Schoeps MK 4V & MK 41V ->
Schoeps 250|0 KCY's (x2) ->
Naiant +60v|Low Noise PFA's (x2) ->
DarkTrain Right Angle Stubby XLR's (x3) ->
Sound Devices MixPre-6 & MixPre-3

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline Brian Skalinder

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #82 on: June 14, 2006, 05:00:00 PM »
and how do you make them [ cute sheets] in cdwave ???

File | Save Cue Sheet
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Offline F.O.Bean

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #83 on: June 14, 2006, 05:13:13 PM »
and how do you make them [ cute sheets] in cdwave ???

File | Save Cue Sheet

do you do this before or after you save your tracks? and how is the cue sheet useful?
Schoeps MK 4V & MK 41V ->
Schoeps 250|0 KCY's (x2) ->
Naiant +60v|Low Noise PFA's (x2) ->
DarkTrain Right Angle Stubby XLR's (x3) ->
Sound Devices MixPre-6 & MixPre-3

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline Brian Skalinder

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #84 on: June 14, 2006, 05:22:42 PM »
do you do this before or after you save your tracks? and how is the cue sheet useful?

Either before, or after.  I save the cue sheet so if I realize after saving the files and closing CD-Wave that I've flubbed the tracking somehow, I can simply open up the file again, load the cue sheet, and make my adjustment.  Also, I save the cue sheet with my raw master so if I need to re-track in the future for any reason I can do so easily.

Edit to add:  It also allows me to track a single time for 24- and 16-bit.  Create cue sheet in 24-bit, then when tracking the 16-bit I just open up the cue sheet.
« Last Edit: June 14, 2006, 05:24:37 PM by Brian Skalinder »
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Re: Dither/resampling/temp file tests in Wavelab
« Reply #85 on: June 14, 2006, 05:32:42 PM »
do you do this before or after you save your tracks? and how is the cue sheet useful?

Either before, or after.  I save the cue sheet so if I realize after saving the files and closing CD-Wave that I've flubbed the tracking somehow, I can simply open up the file again, load the cue sheet, and make my adjustment.  Also, I save the cue sheet with my raw master so if I need to re-track in the future for any reason I can do so easily.

Edit to add:  It also allows me to track a single time for 24- and 16-bit.  Create cue sheet in 24-bit, then when tracking the 16-bit I just open up the cue sheet.

so when you go to open a cue sheet, do you have to open the whole wav to or just the cue sheet ??? im trying it right now FWIW
Schoeps MK 4V & MK 41V ->
Schoeps 250|0 KCY's (x2) ->
Naiant +60v|Low Noise PFA's (x2) ->
DarkTrain Right Angle Stubby XLR's (x3) ->
Sound Devices MixPre-6 & MixPre-3

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline F.O.Bean

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #86 on: June 14, 2006, 05:35:33 PM »
ok, so you can open just the cue sheet, now my next question is: once all my 24-bit tracks are track-marked, i save the cue sheet per set or per disc ??? what do ya'll do?

oh and thanks brian, this was always a clueless subject for me since i always just did 16-bit
Schoeps MK 4V & MK 41V ->
Schoeps 250|0 KCY's (x2) ->
Naiant +60v|Low Noise PFA's (x2) ->
DarkTrain Right Angle Stubby XLR's (x3) ->
Sound Devices MixPre-6 & MixPre-3

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline Brian Skalinder

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #87 on: June 14, 2006, 05:51:26 PM »
so when you go to open a cue sheet, do you have to open the whole wav to or just the cue sheet ??? im trying it right now FWIW

CD-Wave associates the cue sheet with a WAV file.  So if you open the cue sheet, CD-Wave will ask if you want to open the associated WAV file.  But you can also load a cue sheet into a WAV file other than the one with which it is associated.  I do the latter.  For example:

[01]  Open 24-bit WAV file
[02]  Track
[03]  Save 24-bit tracks
[04]  Save cue sheet (this sheet is now associated with the 24-bit file)
[05]  Dither 24-bit file in other editor to 16-bit and save 16-bit WAV file
[06]  Open 16-bit WAV in CD-Wave
[07]  Load cue sheet
[08]  Click "No" when CD-Wave asks if I want to open the associated 24-bit WAV file
[09]  Save 16-bit tracks

i save the cue sheet per set or per disc ??? what do ya'll do?

I do the above for a recording that fits on a single 16-bit CD.  If it's longer than a single CD, I do [01-08] and then:

[09]  Rename the tracks from Txx to D1Txx and D2Txx such that all the D1 tracks fit on a single disc, same for the D2, etc.
[10]  Save 16-bit tracks
[11]  Save separate 16-bit cue sheet
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Offline F.O.Bean

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #88 on: June 14, 2006, 05:56:10 PM »
so when you go to open a cue sheet, do you have to open the whole wav to or just the cue sheet ??? im trying it right now FWIW

CD-Wave associates the cue sheet with a WAV file.  So if you open the cue sheet, CD-Wave will ask if you want to open the associated WAV file.  But you can also load a cue sheet into a WAV file other than the one with which it is associated.  I do the latter.  For example:

[01]  Open 24-bit WAV file
[02]  Track
[03]  Save 24-bit tracks
[04]  Save cue sheet (this sheet is now associated with the 24-bit file)
[05]  Dither 24-bit file in other editor to 16-bit and save 16-bit WAV file
[06]  Open 16-bit WAV in CD-Wave
[07]  Load cue sheet
[08]  Click "No" when CD-Wave asks if I want to open the associated 24-bit WAV file
[09]  Save 16-bit tracks

i save the cue sheet per set or per disc ??? what do ya'll do?

I do the above for a recording that fits on a single 16-bit CD.  If it's longer than a single CD, I do [01-08] and then:

[09]  Rename the tracks from Txx to D1Txx and D2Txx such that all the D1 tracks fit on a single disc, same for the D2, etc.
[10]  Save 16-bit tracks
[11]  Save separate 16-bit cue sheet

+T Brian, thanks alot :)

i have one more question tho, since all of this batch-processing stuff came to light, shouldnt i resample/dither the master wavs to 16-bit THEN load the 16-bit files into cdwave, cut into tracks, save cue sheet, THEN re-open the master 24/96 files and use the cue sheet on them ??? that way  then i could rename everything accordingly :)

does that make sense ???

this is all new and confusing to me, im sure after a few more shows i'll have it down like butta :)
Schoeps MK 4V & MK 41V ->
Schoeps 250|0 KCY's (x2) ->
Naiant +60v|Low Noise PFA's (x2) ->
DarkTrain Right Angle Stubby XLR's (x3) ->
Sound Devices MixPre-6 & MixPre-3

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline Brian Skalinder

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Re: Dither/resampling/temp file tests in Wavelab
« Reply #89 on: June 14, 2006, 06:01:47 PM »
i have one more question tho, since all of this batch-processing stuff came to light, shouldnt i resample/dither the master wavs to 16-bit THEN load the 16-bit files into cdwave, cut into tracks, save cue sheet, THEN re-open the master 24/96 files and use the cue sheet on them ??? that way  then i could rename everything accordingly :)

does that make sense ???

I don't follow.  Either way, you're tracking within one file (either 16- or 24-bit) and loading the cue sheet into the other.  I don't follow why it would matter whether you do 24-bit first, then 16-bit, or vice versa.
Milab VM-44 Links > Fostex FR-2LE or
Naiant IPA (tinybox format) >
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