PDA

View Full Version : iTunes WAV -> AIFF adds volume adjustment field info



Timbo
2006-10-01, 11:31
Hi folks,

After reading here how AIFF files store tags in them and how WAV files don't (so if my iTunes database got screwed I would be in a pickle for example as regards 'year' and 'genre' tags that at present sit nicely in my iTunes library!) I decided to use iTunes to convert a few WAV to AIFF to check sound quality (don't ask I know they are identical) and low and behold I do get tags when I look at the AIFF file on my music folder directly with Slim Server. But I also have a 'volume adjustment' field and it has a value in it - now I wonder why this is? I haven't asked iTunes to adjust volume and neither have I asked Slimserver either? And what on earth is it comparing itself to to decide on the volume adjustment?

Anyone have any clues?

:-)

Mark Lanctot
2006-10-01, 11:56
I'm not sure how volume adjustment got in there, but you can disable SlimServer doing anything with it in Player Settings - Audio - Volume Adjustment/ReplayGain (last item).

Timbo
2006-10-01, 15:23
Note you still don't have tags because AIFF doesn't support tags. SlimServer is reading the "tag" information from the iTunes database.

If your iTunes database gets corrupted you will lose all this info.

I'm not sure how volume adjustment got in there, but you can disable SlimServer doing anything with it in Player Settings - Audio - Volume Adjustment/ReplayGain (last item).

"AIFF is a common uncompressed audio file format, and is compatible with Apple Macintosh computers. Note that AIFF files can contain ID3 Tags, so the AIFF format is ideal for importing uncompressed audio into software that understands ID3 tags, such as iTunes"

This qoute taken from Riptastic! AIFF Encoder - methinks AIFF uses consumer 'ID3 ' chunk tagging to store tag info, not the pro chunks used by other Apple software.

Incidentally, when I look at AIFF files in Slimserver I look at them by browsing the music folder which is not the same drive iTunes music is stored on and the file in question is not indexed in the iTunes library at all (it was copied to the other drive so cannot be referencing the iTunes database). A similar WAV file given the same treatment does not display this info at all.

Info is:

Title: Crawling up a Hill
Artist: Katie Melua
Album: Call Off The Search
Genre: Jazz
Track: 2
File Format: AIFF
Duration: 3:25
Volume Adjustment: -9.67 dB
Year: 2003
File Length: 36,239,488 Bytes
Bitrate: 1411kbps
CBRSample Rate: 44.1 kHz
Sample Size: 16 Bits
ID3 Tag Version: ID3v2.2.0
Location: D:\My Music\02 Crawling up a Hill.aif (Download)
Date Modified: Sunday, October 1, 2006, 9:57:04 PM

Anyway - about this 'Volume Adjustment: -9.67 dB'...anyone have any inside info on where iTunes got that from when it made the file originally..?

:-)

Mark Lanctot
2006-10-01, 15:25
Huh. Well sorry for the incorrect info. I'll revise my post.

Still not entirely sure why you're not using a lossless, compressed format like FLAC or ALAC.

SteveEast
2006-10-01, 16:15
I assume you double checked that the WAV original doesn't have iTunes volume adjustment set?

And that iTunes Sound Check isn't set?

Steve.

Timbo
2006-10-02, 06:58
Yeah I thought that Steve, but no the original doesn't have volume adjustment set - tried converting another track later just to see and that had a volume adjustment also - perhaps it's an iTunes 6 bug (not tried 7 as worried it will mess up something :-)

Actually this isn't a big concern as Slimserver doesn't use the info...just wondered thats all.

:-)

SteveEast
2006-10-02, 07:40
I just tried something similar - converted an AAC track to WAV and then AIFF with iTunes 6. No replay gain showing in SS or dBPowerAmp.

Got me stumped...

What was the original source of your WAV files? Ripped with...?

Steve.

Timbo
2006-10-02, 09:12
They were ripped with EAC, to WAV and then iTunes via iTunesEncode - just checked and haven't got EAC nomalise switched on - strange :-/

Mark Lanctot
2006-10-02, 10:11
They were ripped with EAC, to WAV and then iTunes via iTunesEncode - just checked and haven't got EAC nomalise switched on - strange :-/

Normalization isn't recommended, and even if you did turn it on, it doesn't write any tags because WAV can't be tagged. Instead it permanently alters the audio data - which is why it's not recommended!

SteveEast
2006-10-02, 10:54
They were ripped with EAC, to WAV and then iTunes via iTunesEncode - just checked and haven't got EAC nomalise switched on - strange :-/

I thought iTunesEncode wrote .M4A files? Or does leaving off the -o cause it to just do the iTunes tagging?

Steve.

Timbo
2006-10-04, 04:48
Hi Steve - this is what my EAC external compressor settings look like (just for your info :-) works great with iTunes "-e "WAV Encoder" -a "%a" -l "%g" -t "%t" -g "%m" -y %y -n %n -i %s -o %d" - nothing in there I hope set them up so long ago no idea what all the switches do now! Thats the problem with EAC isn't it, lots to set-up.

:-)

SteveEast
2006-10-04, 06:09
OK, I did some research and understand how iTunesEncode works now. Looks like that was a dead end.

I don't see that you confirmed that iTunes Sound Check isn't set. It isn't I assume?

And there's an Equalizer as well (bottom right hand side). That's disabled as well?

Not that I would have expected either of these to affect a transcoding, but...

Steve.

Timbo
2006-10-05, 14:19
No sound check selected, Equalizer off...it's a mystery :-)

SteveEast
2006-10-05, 14:51
OK, take one of your WAV files and save it to your desktop. Rename it. Then add it back into your iTunes library. Check the properties, just the name should be set. Now convert it to AIFF. Check with SS for volume adjustment - sure as hell shouldn't be any.

Steve.

Spies
2006-10-05, 22:22
Newer versions of iTunes will add the "sound check" tag to all files
it knows how to tag. This includes AIFF but not WAV. It does not
matter if sound check is turned on or off in iTunes like it used to.

On 10/5/06, SteveEast
<SteveEast.2f85xn1160085301 (AT) no-mx (DOT) forums.slimdevices.com> wrote:
>
> OK, take one of your WAV files and save it to your desktop. Rename it.
> Then add it back into your iTunes library. Check the properties, just
> the name should be set. Now convert it to AIFF. Check with SS for
> volume adjustment - sure as hell shouldn't be any.
>
> Steve.
>
>
> --
> SteveEast
> ------------------------------------------------------------------------
> SteveEast's Profile: http://forums.slimdevices.com/member.php?userid=4193
> View this thread: http://forums.slimdevices.com/showthread.php?t=28157
>
>

Timbo
2006-10-06, 07:57
OK, take one of your WAV files and save it to your desktop. Rename it. Then add it back into your iTunes library. Check the properties, just the name should be set. Now convert it to AIFF. Check with SS for volume adjustment - sure as hell shouldn't be any.

Steve.

Just did that - still has volume adjustment - I reckon my iTunes is broke! Tell you why, when I did first import from desktop didn't check I had 'WAV' as Advanced/Import option - just presumed it was as always is. And lo and behold the file was imported as WAV - but when I went to edit these options to convert to AIFF for the next bit of the test I found the options were set to AIFF!! So why did it import the file as WAV then...double checked file definitely WAV..really weird. Thinking of upgrading to 7 anyway so lets hope it clears these thing up!

:-)

SteveEast
2006-10-06, 09:07
Importing a file doesn't do a conversion - at least it doesn't in iTunes 6. That setting is only used for ripping and the "Convert to" menu. Kinda weird.

Steve.

Timbo
2006-10-06, 11:01
Hey something else just found with iTunes 7 (had to try it!) - album art now gets imported and added to any file (in the iTunes database supposedly not the file) - including WAV - but you can't drag and drop art onto a WAV file! So iTunes can do it, but the user can't...:-(

eschurr
2006-10-06, 13:39
Not sure if this is relevant, but i'll offer it up anyway.

I've been using MP3Gain with slimserver and an SB3 for quite a while and LOVING how it keeps the songs at relatively the same volume.

However, i recently upgraded to slimserver 6.5 and now i'm getting weird, huge volume adjusment values. Can't tell where they're coming from and it's really a bummer.

-- MP3Gain doesn't show such large values
-- i had sound check turned on in iTunes (altho i don't like the sonic quality of sound check) but i turned it off. I even fiddled with the volume adjustment slider in iTunes but it makes no difference to slimserver.

I think there's a bug in 6.5.

SteveEast
2006-10-06, 15:49
Hey something else just found with iTunes 7 (had to try it!) - album art now gets imported and added to any file (in the iTunes database supposedly not the file) - including WAV - but you can't drag and drop art onto a WAV file! So iTunes can do it, but the user can't...:-(

That's interesting. I hadn't realised until you posted that you can't add artwork to WAVs in iTunes - I had just assumed iTunes would allow it but keep it separate.

Steve.

SteveEast
2006-10-06, 15:55
Not sure if this is relevant, but i'll offer it up anyway.

I've been using MP3Gain with slimserver and an SB3 for quite a while and LOVING how it keeps the songs at relatively the same volume.

However, i recently upgraded to slimserver 6.5 and now i'm getting weird, huge volume adjusment values. Can't tell where they're coming from and it's really a bummer.

-- MP3Gain doesn't show such large values
-- i had sound check turned on in iTunes (altho i don't like the sonic quality of sound check) but i turned it off. I even fiddled with the volume adjustment slider in iTunes but it makes no difference to slimserver.

I think there's a bug in 6.5.

Since the iTunes volume adjustment slider certainly works in SS 6.2.1 (I have one track with it cranked up to +100%, which SS shows as 6.02 dB, and the difference is obviously obvious), it does seem like their might be a 6.5 problem.

What volume adjustment values does SS show for you?

Steve.

eschurr
2006-10-06, 16:04
All the information is in this other thread

http://forums.slimdevices.com/showthread.php?t=28152

SteveEast
2006-10-06, 16:17
Newer versions of iTunes will add the "sound check" tag to all files
it knows how to tag. This includes AIFF but not WAV. It does not
matter if sound check is turned on or off in iTunes like it used to.


Jeez, I missed this post...getting old....gotta do some digging on this one...

Hmmm, one of the posts on the Apple forums suggest that you have to turn off Sound Check on both the Playback Preferences tab and the Advanced/Burning tab.

Steve.

SteveEast
2006-10-06, 16:30
All the information is in this other thread

http://forums.slimdevices.com/showthread.php?t=28152

Didn't I read somewhere that SS 6.5 prioritises tags differently to previous versions?

I did...http://forums.slimdevices.com/showpost.php?p=141839&postcount=26

Steve.

eschurr
2006-10-07, 14:33
Which versions of iTunes automatically puts the sound check tags on? i haven't jump to v 7.

where does iTunes write the sound check information? in what tags?

SteveEast
2006-10-07, 15:07
Which versions of iTunes automatically puts the sound check tags on? i haven't jump to v 7.

where does iTunes write the sound check information? in what tags?

V6 doesn't. That's about all I can say.

Steve.