Topic: Sample Rate Conversion from 48 > 44.1 in Audacity?

[dean]

SSIA.  Anyone?

Thanks!

[rdflash]

select all.

"project rate" in bottom left of computer screen.

should be on 48, then select 44.1

[Patrick]

select all.

"project rate" in bottom left of computer screen.

should be on 48, then select 44.1

Actually, do this:

1. Select All.

2. Click the down arrow on the stereo audio file, click "set rate."

3. Choose 44100

[rdflash]

whats the diff??

I do it both ways...

[Patrick]

Well, upon reading the Audacity help page, there really isn't any difference.  Whoops.

So, Dean, take your pick. 

[rdflash]

Well, upon reading the Audacity help page, there really isn't any difference.  Whoops.

So, Dean, take your pick. 

Oh ok, good, I thought I was doing something wrong again lol

[Brian Skalinder]

Well, upon reading the Audacity help page, there really isn't any difference.  Whoops.

So, Dean, take your pick. 

Audacity's Help file leaves a bit to be desired.  There is a difference.  The Set Rate option only impacts playback and doesn't change the samples themselves, whereas the Project Rate actually results in sample rate conversion.

Try it (I just did using Audacity 1.2.4):  using Set Rate to change from 48 kHz to 44.1 kHz will produce a 48 kHz file (check in WAV properties via Windows or some such) that simply plays back at 44.1 kHz, and as such will sound slow since the samples are still at 48 kHz.  But using Project Rate will actually perform the sample rate conversion to 44.1 kHz and therefore play back at proper speed.

FWIW, 24-bit workflow for Audacity:  http://taperssection.com/index.php?topic=71191.0

Edit to add:  Oh, and going from 48 kHz to 44.1 kHz is called sample rate conversion or resampling.  Dithering is one mechanism by which one converts from a higher bit-depth to a lower bit-depth, e.g. 24-bit > 16-bit.

[dean]

Hey, +T to all 3 of you.  Thanks for your quick assistance.

A related question that's Mac related.  So I resampled down to 44.1, exported, then popped the tracks into xACT to fix sbe's.  Said it didn't find any errors.  I haven't had that happen before.  Anything to worry about?

Thanks again!!

[dean]

OK, sorry to bump a way old thread, but I had to check it to reconfirm, and when changing the sample rate conversion it causes another odd, Mac related issue.  I'm hoping Patrick can help with this one.

So, I've changed rate from 48 > 44, then make my wav's.  Then I pop 'em into xACT to fix sbe's.  However, it doesn't find any sbe's.  What gives with that and is it a problem for any reason?

TIA!

[Patrick]

OK, sorry to bump a way old thread, but I had to check it to reconfirm, and when changing the sample rate conversion it causes another odd, Mac related issue.  I'm hoping Patrick can help with this one.

So, I've changed rate from 48 > 44, then make my wav's.  Then I pop 'em into xACT to fix sbe's.  However, it doesn't find any sbe's.  What gives with that and is it a problem for any reason?

TIA!

Whenever I track with Audacity, I always have SBE's to fix.  What does xACT say when you try and fix them?  I guess if the "nothing is wrong, no need to fix" message comes up, you're good.  But again, I have never seen this when tracking in Audacity.  What version are you running?

[dean]

OK, sorry to bump a way old thread, but I had to check it to reconfirm, and when changing the sample rate conversion it causes another odd, Mac related issue.  I'm hoping Patrick can help with this one.

So, I've changed rate from 48 > 44, then make my wav's.  Then I pop 'em into xACT to fix sbe's.  However, it doesn't find any sbe's.  What gives with that and is it a problem for any reason?

TIA!

Whenever I track with Audacity, I always have SBE's to fix.  What does xACT say when you try and fix them?  I guess if the "nothing is wrong, no need to fix" message comes up, you're good.  But again, I have never seen this when tracking in Audacity.  What version are you running?

I'm running 1.2.5.  The xACT output message/pop up says: 
shntool [fix]: warning: no shift direction specified - assuming backward shift
shntool [fix]: error: everything seems fine, no need for fixing

I'll burn to cd and see if it plays.  Seems like I'm good to go, though...

Thanks, and I'll let you know the results.  Another T your way in 12.

Cheers,
Dean

[taylordb]

OK, sorry to bump a way old thread, but I had to check it to reconfirm, and when changing the sample rate conversion it causes another odd, Mac related issue.  I'm hoping Patrick can help with this one.

So, I've changed rate from 48 > 44, then make my wav's.  Then I pop 'em into xACT to fix sbe's.  However, it doesn't find any sbe's.  What gives with that and is it a problem for any reason?

TIA!

Whenever I track with Audacity, I always have SBE's to fix.  What does xACT say when you try and fix them?  I guess if the "nothing is wrong, no need to fix" message comes up, you're good.  But again, I have never seen this when tracking in Audacity.  What version are you running?

You shouldn't get any SBE's when tracking in Audacity if you do the following before you start:
View > Set Selection Format > cdda min:sec; frames 75fps
Edit >Snap-to > Snap-to On

That way you are always snapping to the exact edge of a frame sector boundry.  You should always do this when cutting a piece out as well.

[dean]

OK, sorry to bump a way old thread, but I had to check it to reconfirm, and when changing the sample rate conversion it causes another odd, Mac related issue.  I'm hoping Patrick can help with this one.

So, I've changed rate from 48 > 44, then make my wav's.  Then I pop 'em into xACT to fix sbe's.  However, it doesn't find any sbe's.  What gives with that and is it a problem for any reason?

TIA!

Whenever I track with Audacity, I always have SBE's to fix.  What does xACT say when you try and fix them?  I guess if the "nothing is wrong, no need to fix" message comes up, you're good.  But again, I have never seen this when tracking in Audacity.  What version are you running?

You shouldn't get any SBE's when tracking in Audacity if you do the following before you start:
View > Set Selection Format > cdda min:sec; frames 75fps
Edit >Snap-to > Snap-to On

That way you are always snapping to the exact edge of a frame sector boundry.  You should always do this when cutting a piece out as well.

Thanks!

Is this on a Mac, I presume?  Also, what other effects would this process have on the wav?

And when you say I should repeat it when cutting a piece of the wav, how do you mean that?  If I do that process at the beginning of the work, would I need to redo it after each cut?

edit:  fat fingers

[Patrick]

OK, sorry to bump a way old thread, but I had to check it to reconfirm, and when changing the sample rate conversion it causes another odd, Mac related issue.  I'm hoping Patrick can help with this one.

So, I've changed rate from 48 > 44, then make my wav's.  Then I pop 'em into xACT to fix sbe's.  However, it doesn't find any sbe's.  What gives with that and is it a problem for any reason?

TIA!

Whenever I track with Audacity, I always have SBE's to fix.  What does xACT say when you try and fix them?  I guess if the "nothing is wrong, no need to fix" message comes up, you're good.  But again, I have never seen this when tracking in Audacity.  What version are you running?

You shouldn't get any SBE's when tracking in Audacity if you do the following before you start:
View > Set Selection Format > cdda min:sec; frames 75fps
Edit >Snap-to > Snap-to On

That way you are always snapping to the exact edge of a frame sector boundry.  You should always do this when cutting a piece out as well.

I knew there was a way to do this but I was never sure (read: too lazy) to find out how to fix it.  I have just been so set in my way of tracking in Audacity and then fixing SBE's in xACT.

So, thanks for the info!


Dean,

If you are getting that display, I guess you have nothing to worry about, unless there is something wrong with xACT (VERY unlikely).  Burn a CD and see if you have clicks between tracks, then you'll know something is wrong.

T's all around.

[dean]

Damn, there's some weird problem with the recording.  It starts the first 2 seconds of the next track on the end of the previous track.  Then it starts it over when it gets to the actual track.   

[taylordb]

Yes, I use a mac.....but I would guess that the functions would be the same on the windows version (if there is one, haven't looked).

Also, the great part about Audacity is that it never physically changes the original wav file.  It only uses it as a reference.  So if you screw up your editing, just delete the audacity file and start over.

[db]

i think "ccda sectors + bytes (snap to samples)"  oughta work too, no?

[dean]

Damn, there's some weird problem with the recording.  It starts the first 2 seconds of the next track on the end of the previous track.  Then it starts it over when it gets to the actual track.   

Can anyone help with this issue, though?  So I do the Project rate sample conversion 48 > 44.1, cut all my tracks, export, then when I try to fix the sbe's is says there are none, but the tracks are messed up as I describe above.  The first few seconds of the next track are both at the end of the current track PLUS at the beginning of the next track.   

[db]

Damn, there's some weird problem with the recording.  It starts the first 2 seconds of the next track on the end of the previous track.  Then it starts it over when it gets to the actual track.   

Can anyone help with this issue, though?  So I do the Project rate sample conversion 48 > 44.1, cut all my tracks, export, then when I try to fix the sbe's is says there are none, but the tracks are messed up as I describe above.  The first few seconds of the next track are both at the end of the current track PLUS at the beginning of the next track.   

maybe: cut up the tracks by cut and then paste into a new "stereo track". once you have all of the tracks/files select "export multiple" under file menu and make sure the bottom left sample rate is set to 44k.

edit: also, when you make your cuts, your selection format needs to be in "snap to". i said it above, but i think it's the "ccda sectors..." selection. ccda ...75 fps may work too, never tried.

[dean]

Fixed!  Here's what happened to fix it. 
1. I started over with the original wav transferred over, opening it as a new file in Audacity. 
2. I then did the sample rate conversion using "project rate" in the bottom left corner of the GUI.
3. "Export as wav", creating a new wav file now in 44.1 kHz.
4. All the usual stuff.

Worked out slick!  I can now begin transferring the 100+ dats that have been sitting around for the last 3 years!   

T's to the thread!   

[digifish_music]

I thought I would just post a link to this free-ware utility from Voxengo r8brain

High quality conversion is yours in batch mode (on PC).

http://www.voxengo.com/product/r8brain/

Download here



digifish