I'm just loving my new iPod touch, however i noticed last night, that it's not perfectly gapless.

Listening to Dark Side of the Moon, i noticed a disturbance in the audio, as it went between tracks. Not a gap, more of a skip sound. Very noticeable while paying attention to it. I'm not sure if it's limited to this album, i'll have to check some others when i get a chance.

This morning before work, I went back to foobar and listened to the same files there. No problem. Gapless and perfect.

I haven't tried listening in iTunes yet. I did try changing the setting for gapless in the itunes info for the entire album, and re-synching. It didn't do anything. I didn't watch the synch though, so i'm not sure if it re-copied the album onto my iPod.

I rip with AAC to flac (individual tracks, no cue), then use foobar to encode to Nero AAC. Only defaults i change on encode, are q0.42, and i use replaygain processing to alter the volume level. Then i dump the files into itunes for iPod management.

Like i said, it plays flawlessly in foobar, but there is a definite skip sound on my iPod.

From about an hour of searching here, I couldn't find a similar problem, but i did find that it is supposed to work properly.

Any hints, suggestions, places to look? I'm going to look at it more carefully tonight if i can.

Just did a quick check on my own and didn't notice anything.

There's an easy way to check though. Record the output during one of the track changes and look at the waveform. If you do the same with the output from foobar or even the original lossless you should be able to notice a gap or spike at the transition if there's a problem with gaps.

I should note that I did just notice one noticeable gap. Though when I replayed the transition it was perfect. I'm not too surprised that there are occasional glitches. And that glitch was while I was quickly skipping to the end of each track so there was a lot of fetching of data. I don't think I've ever heard a gap during normal listening.

I'm interested to hear what you find. Might test on my own if I get the chance as well.

Make sure that you are using file names of *.m4a instead of the default *.mp4. Also make sure that iTunes is scanning your files for gapless playback. Many people loath iTunes when it has to scan their library for gapless playback but it is the only way to get gapless on an iPod.

There are some instances when iPods are not 100% gapless but, for the most part, they are gapless. I find more errors when using the Nero AAC encoder. I don't know why but that is the encoder when I experience more gaps. My iPod (and iTunes library) seems fine when playing back iTunes AAC and Lame mp3 files.

Hmm, .m4a, i was wondering about that. Any painless way of renaming, other than basically deleting my library and re-adding all the music?

Itunes performs terribly on my laptop, even though it's a fairly powerful machine.

You are going to have issues. You see, iTunes thinks that mp4 files are video files. mp4 is such a generic file extension as it can house audio, video, or a combination of the both. That is why Apple came up with different naming schemes. m4a is used for AAC audio files, m4v and mp4 for video files, m4p for purchased iTunes Store AAC files, and m4b for books. Apple did this so that people wouldn't have 1000+ files all with extensions of mp4. It would be hard to determine which files had audio content, which files had video content, and which files had both. It might not be hard for users like you are me (since we can just look at the file sizes) but remember that iPods and iTunes are both targeted towards being extremely user friendly. I don't think that most people would look at their file sizes in order to determine if a mp4 file is an AAC track or a video.

Anyway, I am sure there are some general Windows commands and I think that foobar2000 can even rename your files. You just have to do a generic command where everything with an extension of *.mp4 gets changed to *.m4a.

The only issue is that the files already added to your iTunes library won't work anymore as iTunes is looking for files with names of *.mp4. You will have to re-add the files to your iTunes library. Sorry but there is absolutely no way around this. You cannot use iTunes to rename the files either.

It sucks but this is life with iTunes. On a side note I think this is a prime example of why foobar2000 should use, by default, the extension of m4a instead of mp4 when using the Nero AAC encoder. dBpowerAMP updated their software to use m4a (along with the Nero AAC encoder) by default, I don't know why foobar2000 doesn't do the same thing. Even portable players/software from other companies such as Microsoft, Creative, Archos, Sony, and SanDisk require that AAC files use the m4a extension.

I appreciate the detailed info.

I still have yet to figure out how to get foobar to use m4a instead of mp4. Even the rename function seems to ignore the filename extension.

I can do the rename easily enough from a command line, however going forward i need to know how to get it to change to m4a.

Thanks again

That part's easy. In foobar preferences, select converter, select "MP4 Nero" and click Edit. In the encoder drop down box, select "custom". Then it lets you change the extention.



Incorrect. It can be tedious, but it can be done. I'll have to look for the blog post, but I found one that has instructions on editing the XML database outside of iTunes so you can change file locations, names, etc. while keeping library ratings, statistics, etc. I've done it and it worked. When I find it, I'll post it here.

OK, I can restate that. I think it is easier just to re-add the files to the iTunes library. You can have iTunes look for the file or go through the tedious process of editing the XML file. I think it is just easier to re-add the files to the iTunes library.

The OP may want to go through the tedious process of editing the XML file if they have all their music rated, want to keep play counts, and so on.

I am not sure how to get foobar2000 or Windows to rename files and change their extensions. I know there are ways to do this though. You might have better luck with DOS and some type of mass renaming command.

Well, it's not that tedious really, especially if you've invested a lot of time into your ratings and playlists.

Basically the steps are:

1. Backup the library.itl file somewhere
2. Open the library.xml file with the text editor of your choice*
3. Use find/replace to change "mp4" to "m4a"
4. Open the original library.itl file from a text editor, select all, delete, save.
5. Open iTunes, and it will attempt to restore the empty itl file using the xml file you just modified.
6. iTunes will have to recalculate your song volumes, which can take some time.
7. When it's all done, exit iTunes.

Open iTunes to verify everything works. It should. It did for me. Now you can delete that backup library.itl file

*This was the only step I personally found tedious. If you have a really big library, the normal notepad application won't open files that big. It took me a bit of searching to find an application that could open such a large text file. There are lots of paid ones but I didn't find any totally free ones. I think I ended up using LargeEdit, which stops working after 30 days.

I didn't find the blog posting I found originally when I did this, but here's another one that says the same thing:

Great info. Thanks all.

As an aside, there are two really good, free notepad replacements out there.
Notepad++:
http://notepad-plus.sourceforge.net/uk/site.htm

Notepad2:
http://www.flos-freeware.ch/notepad2.html

Notepad2 is the more simple of the two, and looks the most like windows notepad. I completely replaced the stock notepad on my system with it.

I'm fairly sure either can open any size file.

***edit***

For future reference. The above method by singaiya did not work for me. I was left with an empty library. Likely because of changes made to iTunes recently, or perhaps because of Vista somehow. Fortunately i wasn't experimenting on my main media computer. I tried many ways, being forced to recreate my small experimental library a few times. The 'iTunes Library.itl' just would not re-create from the .xml. If it was corrupted, blanked, or deleted, i would just have an empty library.

After much experimentation and googling, i did figure out a method that works with my test library, without screwing anything up, short of duplicating playlists. I haven't applied it to my main library yet, as i'm still at work. Maybe this weekend.

If anyone cares to know how i'm doing it, let me know, and i'll post my method, and results with my main library. As with singaiya's method above, i think it could also be used for changing the location of your music files, without messing up your iTunes library.

+1

Been using it for years.

gerwin,
I forgot to mention the fact that I was on something like iTunes 7.2, maybe 7.1 when I did that. It was at least a year ago that I had to change paths on many of my files. Could you post your method here anyway, as well as what version iTunes you're using?

Latest version of iTunes - 8.0.2.20.

I was in a hurry when i tried it on the weekend, and ended up screwing up my library, Dumb. Here's how it was working for me during my tests.

1. Back up your itunes library file - itunes library.itl (itunes has to be closed for this.)
2. Copy your itunes library.xml to your desktop
3. Open iTunes
4. Delete all your music from itunes
5. Rename music files from .mp4 to m4a
6. Open the desktop copy of itunes library.xml using a text editor, do a find/replace to change the filenames of your songs to m4a. Save it.
7. In iTunes, go to File/Library/import playlist....
8. Select the desktop copy of itunes libary.xml and open

That's pretty much it. It reloads your library from the xml, with all the information intact. It will duplicate any playlists however, so you'll have to delete the duplicates. In my testing it didn't hurt anything else. Like i said though, i screwed up doing it with my real library, so i suggest you do some testing first.



In the end however, i couldn't get Nero AAC's to play gapless on my Touch. It didn't matter if they were named .mp4 or m4a. They would play gapless in FooBar, and in iTunes, but not on my iPod. Perhaps Apple AAC would do gapless fine, but i don't want to use iTunes for encoding as foobar is a much nicer tool. I ended up re-encoding all my Pink Floyd albums with Lame, which plays gapless fine on my iPod. This is one of the nice things about keeping your music archived as flacs. You can painlessly switch codecs without re-ripping your albums. This is an ongoing process as i find other albums that need to be gapless.

To make the album play gapless, try this:

Select the album in the "artist" or "album" pane

Do a "Get Info". Select "options" from the window that comes up.

Look to see if the "Gapless Album" flag is set. If not, pick "Yes" and hit "OK". This fixed a lot of tracks for me, even though they should have been ripped properly to begin with...

The "gapless album" option actually has nothing to do with how iTunes or iPods play the songs. All it does is tell iTunes to not crossfade the songs when playing them if the crossfade option is enabled. So it is strange that it would fix your issues.

That seems to be the consensus, yes - though I wish Apple's FAQ on the subject was worded a little more concisely.

I don't know! I re-loaded some live albums to my iPod after setting gapless on them, and they played just fine. I have crossfade turned off anyway... I wonder if I inadvertently changed something else? I've heard that having huge embedded album art can cause a momentary hesitation when a track is loaded, though that shouldn't matter unless it's refilling the buffer from disk. I can't think of anything else I might have altered.

I think the "Gapless Album" flag actually made it worse. It went from a skip sound, to an actual gap. A largish fraction of a second of silence.

It may not have been the flag's fault though, as i was trying a few things at once.


I noticed one strange thing with the pink floyd .mp3's. It seems to get the track length wrong on my iPod. The indicators will be at the end of the song, and it will continue playing, sometimes for 10 seconds or more. Eventually it switches (gaplessly) to the next track.

Maybe i'll have to dig out the cd's and re-rip them, however i'm not anxious to do that since they play fine as it is. (If it ain't broke....)

IIRC, that setting is there to tell iTunes to not use the cross-fader. It does not need to be checked for gapless playback to work. This was a pretty big misconception when gapless playback was first implemented in iTunes. Maybe the behavior has changed since then, but I seriously doubt it.

http://support.apple.com/kb/HT1797

EDIT: Oh, I see that kornchild2002 already said this. Well, at least now you have a link and a quote for your viewing pleasure.

Yes, the time indicator does some really strange things when both iPods and iTunes play things back gaplessly. It is bet to just ignore the time slider and only listen for the gaps. You can playback the files in iTunes to discover that it does the same thing.

Are you letting iTunes scan your mp3 files for gapless playback? I have found that iTunes (and my iPod) is buggy when it comes to gapless playback of Nero AAC files, FhG mp3 files, and mp3 files created by other unknown encoders. I haven't had any problems with iTunes AAC or Lame mp3 files. The issue that I experience is that a very small gap can be heard. I can then skip back, play the song again, and then my iPod/iTunes will not have a gap.

I don't know why but the issue seems to be isolated with Nero AAC, FhG mp3, and other unknown mp3 files. I guess iTunes is still not perfect when scanning for gapless playback.

I have no idea how to do this. I've searched every option i could find, and the only reference to gapless i've found is the above mentioned 'part of a gapless album' tag.

Hi,

I don't know if you have already solved this issue, but I just happened to browse into this topic and it occured to me that I once had a similar experience, so it may help somebody else.

On the iPod Touch, there is a function called Sound Check, which helps leveling out volume level variations between individual songs. This function, when enabled, may cause a clearly audible glitch between consecutive tracks on an otherwise gapless album. It is only active on the iPod, not in ITunes.

To switch this function off, you need to go to Settings --> Music -- Sound Check and set this to Off.

It solved my problems at least...

Kind regards
Tom

I noticed that latest Nero AAC encoder has occasionally issues creating files that are gapless. I switched over from MP3 to AAC last weekend and immediately found tracks that weren't gapless even in foobar2000. Not even when encoded with highest quality settings. Same files encoded with iTunes worked properly both with foobar and iPod.

For verification you could feed both the original and Foobar's disk-writer output into Synchrotron. The exact number of added frames could be an indication of what's happening there.

Sounds like you doubt foobar's ability to properly utilize gapless data...

No, Foobar should be certainly able to do that (at least for Nero AAC and LAME), but you had reported that some tracks weren't even gapless in Foobar. Was the above an example of that or just two random files from your weekend session?

That was from files that have audible glitch on transition.
Here's what transition should look like:


And this is after Nero encoding:

That does indeed look like an encoder issue not related to gapless meta data. The encoder seems to have accuracy problems at the beginning and (possibly) end of files.

Is this from decoding 2 separate MP4 files, or from 1 file with 2 (or more) tracks inside?

Two separate files. I create one file per one CD track.

I noticed that my new iPod touch 3G has problems with gapless files and came across this (old) thread. The interesting part is that all my Nero encoded AAC files play gaplessly on my iPod classic but do not on the touch.

Well, I have similar problems with that also. Mind you, I have iPod Touch with 3.1.1 firmware, I heard there is 3.1.2 out, maybe it will correctt the glitches. I didn't had problems with 2.* firmwares.
Also, I can't add Nero mp4 files to iPod nano 2G. Only when I remove cover and convert extension to m4a. They work as they should on iPod Touch.

All my files have the m4a extension of course.
Do you mean that the same files that worked fine under 2.x stopped being gapless under 3.1.1?