foo_pod - Foobar2000 meets the iPod, iPod -> Foobar2000 0.8 Options

[binkgle]

Does the database format (ie. 4.7/4.8) directly correspond to the iTunes version?  How do I know what database format I am using?

it depends on which version of itunes you had when you first got your ipod and which you have now. if you've always had itunes 4.8 or earlier, then you use the earlier database format in foo_pod. for now that's the only one that really works in foo_pod, though it seems that that's going to change soon (thx aero!!!!!!!!! )

any later versions and you use the 4.9 database

[Sandman2012]

for now that's the only one that really works in foo_pod, though it seems that that's going to change soon (thx aero!!!!!!!!!   )

[nicholas]

Interesting. I am using iTunes 6 (the only version I have run) with the latest iPod firmware and have had no problems using foo_pod. If I am using the 4.9 database format, it seems Aero has done a good job supporting it.

[Veritas]

Is there a way to get iTunes to utilize Replaygain values in place of Soundcheck values if I don't use foo_pod to transfer music onto my iPod?

It seems like it's possible, but I might be missing how to do it. The preferences talk about translations between the two, but I can't figure out how to send those vales to the iTunes database. I'm assuming that the intended usage is to have foo_pod communicate those values directly to the ipod during transfer. I would prefer using iTunes for syncing my iPod because I rely heavily on smart playlists.

What I would like to do is send the Replaygain values to iTunes and have iTunes record them as Soundcheck settings.

Is this possible using foo_pod?

[david_dl]

Is there a way to get iTunes to utilize Replaygain values in place of Soundcheck values if I don't use foo_pod to transfer music onto my iPod?

It seems like it's possible, but I might be missing how to do it.  The preferences talk about translations between the two, but I can't figure out how to send those vales to the iTunes database.  I'm assuming that the intended usage is to have foo_pod communicate those values directly to the ipod during transfer.  I would prefer using iTunes for syncing my iPod because I rely heavily on smart playlists.

What I would like to do is send the Replaygain values to iTunes and have iTunes record them as Soundcheck settings.

Is this possible using foo_pod?

I plan on adding this feature to foo_sendtopod (which uses iTunes to do the transfer). However I need to work out how to translate the replay gain value to a value from -100 to 100. I assume this has something to do with logarithmic and linear scales, not something I understand fully. I'm assuming foo_pod already does this, would anyone like to reveal how? Or I could work it out for myself, but i'd rather not .
Also, does soundcheck support track and album gains? I don't think it does, which is annoying, as on my iPod I sometimes listen to full albums, or I listen to shuffle.

Edit: On thinking about it wouldnt the -100 to 100 value be logarithmic, because that is the way we hear? Hmm. On looking at my replay gain values in foobar, they go from about -13 dB to +64 (silence, the hidden tracks on Tool - Undertow). But most are clearly in a 10-10 range. I guess it could work to multiply RG by 10, then set anything outside the range to max or min (this shouldnt affect most tracks as they are within the range)

This post has been edited by david_dl: Jan 25 2006, 08:45

[Veritas]

When I use MP3Gain to do volume leveling I know that I have some albums that need -12dB. I may even have some that need more. Since the values for soundcheck seem to be percentages, then the min would be half as loud and the max would be twice as loud.

Not sure what that means to this situation though. The exact decibels needed to make something twice as loud are relative to how loud it is to start, isn't it?

I think I'm just confusing myself, hopefully someone else will answer.

[ReD-BaRoN]

Is there a way to get iTunes to utilize Replaygain values in place of Soundcheck values if I don't use foo_pod to transfer music onto my iPod?

It seems like it's possible, but I might be missing how to do it.  The preferences talk about translations between the two, but I can't figure out how to send those vales to the iTunes database.  I'm assuming that the intended usage is to have foo_pod communicate those values directly to the ipod during transfer.  I would prefer using iTunes for syncing my iPod because I rely heavily on smart playlists.

What I would like to do is send the Replaygain values to iTunes and have iTunes record them as Soundcheck settings.

Is this possible using foo_pod?

I plan on adding this feature to foo_sendtopod (which uses iTunes to do the transfer). However I need to work out how to translate the replay gain value to a value from -100 to 100. I assume this has something to do with logarithmic and linear scales, not something I understand fully. I'm assuming foo_pod already does this, would anyone like to reveal how? Or I could work it out for myself, but i'd rather not .
Also, does soundcheck support track and album gains? I don't think it does, which is annoying, as on my iPod I sometimes listen to full albums, or I listen to shuffle.

Edit: On thinking about it wouldnt the -100 to 100 value be logarithmic, because that is the way we hear? Hmm. On looking at my replay gain values in foobar, they go from about -13 dB to +64 (silence, the hidden tracks on Tool - Undertow). But most are clearly in a 10-10 range. I guess it could work to multiply RG by 10, then set anything outside the range to max or min (this shouldnt affect most tracks as they are within the range)

Can we have more details on this foo_sendtopod? How is this going to differ feature wise from foo_pod?

[Veritas]

I just found this at wikiPodLinux

The Track List has Track Items as its children. The number of Track Items is the same as the number of songs.

[Offset: 76, Field: Soundcheck]

The SoundCheck value to apply to the song, when Sound Check is on. The value to put in this field can be determined by the equation: X = 1000 * 10 ^ (-.1 * Y) where Y is the adjustment value in dB and X is the value that goes into the SoundCheck field. This works perfectly well with ReplayGain derived data instead of the iTunes SoundCheck derived information.

Also, I also read a couple places that iTunes only uses the soundcheck values when it initially imports it. After that it uses the stored value in its database.

This post has been edited by Veritas: Jan 25 2006, 16:21

[david_dl]

Can we have more details on this foo_sendtopod?  How is this going to differ feature wise from foo_pod?

http://www.hydrogenaudio.org/forums/index....showtopic=40854

It just controls iTunes to send (and possibly transcode) files to the iPod, then tag them quite basic, but handy if you want to use iTunes but don't want to manually transcode and tag (afaik iTunesEncode doesnt work with foo_pod because iTunes locks the iPod database, so you are limited to the nero AAC encoder which AFAIK is slower, hasn't been proven to be as good, and can cause skipping on some iPods)

The Track List has Track Items as its children. The number of Track Items is the same as the number of songs.

[Offset: 76, Field: Soundcheck]

The SoundCheck value to apply to the song, when Sound Check is on. The value to put in this field can be determined by the equation: X = 1000 * 10 ^ (-.1 * Y) where Y is the adjustment value in dB and X is the value that goes into the SoundCheck field. This works perfectly well with ReplayGain derived data instead of the iTunes SoundCheck derived information.

Thanks, thats just what I was looking for.

Also, I also read a couple places that iTunes only uses the soundcheck values when it initially imports it. After that it uses the stored value in its database.

The iTunes API provides a function to set "Volume adjustment" which I assume is soundcheck. It would be easy enough to set when adding files, but perhaps I could also implement a 'scanner' that goes through the files on the iPod, locating them in the foobar2000 database and adding these values, but this would be very slow and rely on tag uniformity between iTunes and foobar.

[Otto42]

The iTunes API provides a function to set "Volume adjustment" which I assume is soundcheck.

Bad assumption.

The iPod has two volume level fields. One corresponds to that volume slider in iTunes Get Info screen, and ranges from -100 to +100. The other corresponds to the volume adjustment via SoundCheck. This is a power level adjustment, which is why it uses that odd logarithmic scale (the 1000 * 10 ^ (-x/10) thing). These are not the same and do not behave in the same manner. Also, the SoundCheck one is not accessible through any iTunes API or setting, it's wholly automatically determined by iTunes.

This post has been edited by Otto42: Jan 25 2006, 20:06

[Veritas]

Also, the SoundCheck one is not accessible through any iTunes API or setting, it's wholly automatically determined by iTunes.

So Otto do you know if the foo_pod replaygain translation adjusts the soundcheck values or the volume adjustment?

If iTunes doesn't read the soundcheck values directly from the file then does that mean that it is stored somewhere in the iTunes Library XML file? Is it possible to manually modify those values so that they reflect replaygain settings?

Foo_pod seems to have some type of importing/exporting feature with XML libraries, but I'm not sure if that only modifies the iTunesDB on the iPod without affecting the iTunes library.

[carmenm]

I have a little problem with the plugin. When i right click on a file from a playlist and goes to foo_pod i dont have send to ipod. I only have send to ipod "send file to ipod as audiobook". How do i manage to have "send file to ipod" ???

[Veritas]

Ok, I did a bunch of digging through this thread today. I'm starting to get a decent handle on how all this Soundcheck/Replaygain stuff works. I would just like to ask a few followup questions to these previous conversations

When I look at the tag of a file that has been "Soundchecked" by iTunes, this is what it says in the "comment" field:  00001020 0000118B 00003555 00004352 0002E675 0002230E 00008000 00008000 0001D4EE 0001D4EE

I thought that as you'd already figured out how to calculate Soundcheck values from Replaygain values, it would just be a matter of adding that into the "comment" field? Guess I was wrong then...

No, you are correct. The catch is that the "just be a matter of adding that into the "comment" field" part is the unknown piece here.

Actually now that I think of it, I think Otto42 determined that the first series of alphanumeric characters (00001020) is just the Sound Check value from the database. But the rest of the groups are apparently unknown, unless someone can point me to more recent information.

That's correct, the first value in that big ugly comment string is the value that iTunes puts into the iTunesDB as the SoundCheck field. foo_pod is now putting a ReplayGain value in that field, since we worked out the conversion equation.

However, the rest of the stuff in that comment baffles me. I don't know what any of it means, and I can't find any obvious correspondence to anything anywhere. But if you figure it out, let us know.

When foo_pod writes replaygain values to the iPod, does it simply replace the first value in the itunNORM field leaving the rest of the values alone? If you guys don't know what the other values represent then it would seem that you either 1) leave them alone and modify the value you do know, or 2) modify the first value and delete all the rest.

If this is the case, then (and I'm probably setting myself up for my own private hell) I'm considering manually editing the itunNORM field with a translated Replaygain setting. Yes, I am that obsessive.

So, first of all, is this even feasible? (Ignoring the massive waste of time) And second, is there any way to harvest the RG/SC translation data from foo_pod so that I don't have to compute it all and then translate to hexadecimal (or whatever format that itunNORM field is in)

If I add replaygain information to my .mp3 files in fb2k, and don't have soundcheck scanning activated in iTunes, that (rg) information should remain untouched, and still play properly on my iPod (when soundcheck is "on"), correct?

Nope. iTunes will overwrite the soundcheck field in the iTunesDB when it creates the file. If it doesn't have volume information from scanning the file, it writes zeros. iTunes doesn't actually change a pre-existing file, it simply rewrites the entire iTunesDB file the way it thinks it should be.

Now this conversation gives me pause. From what I understand, the itunNORM field is not directly read from the audio file, but it will be read when adding the file to the iTunes library. So, I think I should be able to turn on soundcheck in itunes, causing it to analyze what's there. Then, modify that data to reflect RG values. Then, delete the iTunes library and finally add all the newly formatted audio files back into the library, leaving soundcheck turned on. Will this work? Will this get around iTunes overwriting the RG values?

[david_dl]

Just for the record, you should definately check here and here

[Veritas]

Yeah, I think I came across that material at some time or another in the last two days. These are the issues I'm trying to address:

1. I need to use iTunes for the smart playlists. I rely on playlists that refer to other playlists as selection criteria.

2. I want the album gain feature of Replaygain.

3. I have been using MP3Gain for a while now, but I always undo the gain changes once the files are transfered to the portable. My wife and I share the same music files and she doesn't like the altered files. If I edit any tags then I have to regain before I can upload it.

I would think that the time invested in getting the Replaygain values into the Soundcheck format now would make my life easier down the road.

[Otto42]

So Otto do you know if the foo_pod replaygain translation adjusts the soundcheck values or the volume adjustment?

I believe it can do either. There's a setting for that, or there used to be. The reason for this setting was that, on older iPods (3G), the soundcheck is not performed on audio using the Line Out on the dock. Newer iPods fixed this flaw.

If iTunes doesn't read the soundcheck values directly from the file then does that mean that it is stored somewhere in the iTunes Library XML file?

Just to be clear, the XML file is *not* the library. The library is the ITL file, the XML file is what I like to call a "write-only" file. iTunes never really reads the XML file.

Is it possible to manually modify those values so that they reflect replaygain settings?

Possible? Sure. You'd have to figure out how the ITL file works.

When foo_pod writes replaygain values to the iPod, does it simply replace the first value in the itunNORM field leaving the rest of the values alone?

Neither foo_pod nor the iPod care what is in the iTunNORM comment. The iPod never, ever, reads tags. Period. It's getting it's information from the iTunesDB. foo_pod writes converted ReplayGain values directly to the proper places in the iTunesDB file on the iPod.

If this is the case, then (and I'm probably setting myself up for my own private hell) I'm considering manually editing the itunNORM field with a translated Replaygain setting.  Yes, I am that obsessive.

Wouldn't do you any good. The iPod does not read the iTunNORM data.

Now, iTunes DOES read this data, but only when the song is initially added to iTunes. After that, it never looks at it again, as far as I know. Although from what the iVolume guy has said on his page, I'm starting to wonder about that.

So, first of all, is this even feasible?  (Ignoring the massive waste of time)  And second, is there any way to harvest the RG/SC translation data from foo_pod so that I don't have to compute it all and then translate to hexadecimal (or whatever format that itunNORM field is in)

It really depends on what exactly your goal here is. I'm uncertain as to what it is, precisely, that you're attempting to accomplish.

Now this conversation gives me pause.  From what I understand, the itunNORM field is not directly read from the audio file, but it will be read when adding the file to the iTunes library.  So, I think I should be able to turn on soundcheck in itunes, causing it to analyze what's there.  Then, modify that data to reflect RG values.  Then, delete the iTunes library and finally add all the newly formatted audio files back into the library, leaving soundcheck turned on.  Will this work?  Will this get around iTunes overwriting the RG values?

That would work, despite being a massive pain in the ass.

Another way that *might* work would be to let iTunes scan the file, thus writing the iTunNorm crap to it, then modifying the iTunNorm data directly, and then using the UpdateInfoFromFile() call in the COM library to force iTunes to reread the file tags. This *might* update volume information from that tag, but that is only conjecture. However, it sounds sorta like what the iVolume guy is doing, although he's doing it on the Mac, it seems. Testing would be needed to see if this would work.

1. I need to use iTunes for the smart playlists.  I rely on playlists that refer to other playlists as selection criteria.

I wrote functionality into my original implementation of smart playlists to allow these sort of smart playlists to work without using iTunes. Since foo_pod is using a highly modified version of that original code, foo_pod *could* implement this, in theory. You'd have to talk to Aero. Basically, foo_pod is not precalculating smart playlists, just letting the iPod do it. But the iPod does not implement the "Playlist" rule. If foo_pod precalculated it (which is what that code I wrote does), then it would work.

This post has been edited by Otto42: Jan 26 2006, 12:37

[Veritas]

First, Otto, I want to thank you for such a thorough answer.

I'm not sure if I will proceed with modifying the iTunNorm value now. If you guys aren't able to figure out what those extra values are, then I seriously doubt I will be able to make any headway. However, I may play around a little with the scheme I outlined in my last post where I modify the iTunNorm and then import it into the iTunes library.

In order to do that though I was hoping you could give me a little more information on the formatting of that value. (I have next to no programming experience) I remember reading in one of the earliest posts regarding the soundcheck variable you mentioned that the digits were reversed. Could you elaborate on that?

For example, if I have a track that i want to apply a -12.0dB gain:

1000 * 10^(-.1 * -12.0) = 15848.931...

Round to 15849 then convert to hexadecimal yields 3DE9, correct?

So how would I enter that into iTunNorm? 00003DE9? 0000E93D?

[Otto42]

For example, if I have a track that i want to apply a -12.0dB gain:

1000 * 10^(-.1 * -12.0) = 15848.931...

Round to 15849 then convert to hexadecimal yields 3DE9, correct?

So how would I enter that into iTunNorm? 00003DE9? 0000E93D?

In iTunNorm, it'll be 00003DE9. In the iTunesDB file, it'll be E93D0000.

[Veritas]

Excellent. Thanks for all your help. If my experiments yield any notable results I'll post them. If not, you can probably safely assume that my brain short-circuited from obsessing over unimportant minutiae.

[david_dl]

Hmm, foo_pod sounds like the best solution to this issue. Will it ever support cuesheets/ CD images? I can't imagine this being particularly hard to implement, as they will always need to be transcoded, and diskwriter (which AFAIK foo_pod's transcoding is based on) supports them. For me this makes it all but completely useless. It would also be nice if it didnt completely block the entire foobar GUI during the transfer.

[ReD-BaRoN]

Hmm, foo_pod sounds like the best solution to this issue. Will it ever support cuesheets/ CD images? I can't imagine this being particularly hard to implement, as they will  always need to be transcoded, and diskwriter (which AFAIK foo_pod's transcoding is based on) supports them. For me this makes it all but completely useless. It would also be nice if it didnt completely block the entire foobar GUI during the transfer.

It would be nice if the source was open and add that support yourself, eh?

This post has been edited by ReD-BaRoN: Jan 27 2006, 15:45

[dalecooper]

Hi there - I'm having a problem with foo pod. I just downloaded foobar and foo pod and they seemed to work as desired. I downloaded them primarily to update my iPod with replaygain values so I could use Soundcheck. However, after scanning my entire playlist for replaygain and updating the iPod database, my iPod no longer shows song information in iTunes - the screen is simply blank. What have I done? Is there anyway to undo this? I like using iTunes for several reasons and I'd like to be able to use both. foobar/foo pod is still showing my iPod contents correctly and will play the files. iTunes has a scroll bar but no track information at all.

Thanks!!

[ReD-BaRoN]

Hi there - I'm having a problem with foo pod.  I just downloaded foobar and foo pod and they seemed to work as desired.  I downloaded them primarily to update my iPod with replaygain values so I could use Soundcheck.  However, after scanning my entire playlist for replaygain and updating the iPod database, my iPod no longer shows song information in iTunes - the screen is simply blank.  What have I done?  Is there anyway to undo this?  I like using iTunes for several reasons and I'd like to be able to use both.  foobar/foo pod is still showing my iPod contents correctly and will play the files.  iTunes has a scroll bar but no track information at all.

Thanks!!

I'm presuming you're using a recent version of iTunes. foo_pod doesn't suport the latest version of the iTunesDB, so once it writes its version of the iPod, iTunes can no longer read it.

[dalecooper]

That was pretty much what I figured. I had read somewhere (maybe on this forum) that someone was using foo pod with iTunes 6.0 successfully, but I guess I should have taken that with a grain of salt. Is it possible to revert the db in some way using iTunes, or am I now stuck waiting for a foo pod update?

This post has been edited by dalecooper: Jan 27 2006, 16:26

[ReD-BaRoN]

That was pretty much what I figured.  I had read somewhere (maybe on this forum) that someone was using foo pod with iTunes 6.0 successfully, but I guess I should have taken that with a grain of salt.  Is it possible to revert the db in some way using iTunes, or am I now stuck waiting for a foo pod update?

This I don't know the answer to, but I suspect one of five things can happen:

1) Drop iTunes and stick with foobar/foo_pod
2) Go back to a previous version of iTunes (4.8) which can read the foo_pod DB
3) Erase your iPod and start over using iTunes only.
4) Wait for a new version of foo_pod which supports the new databases
5) Write a new foobar plugin for the iPod (from scratch)

This post has been edited by ReD-BaRoN: Jan 27 2006, 16:38