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[lalittle]

I've noticed recently that while my newer rips play back gaplessly on the iPod (as long as I let the song play from the beginning) my "older" rips do not.  These older rips are a combination of VBR and CBR encodes using the LAME encoder in MC, and the format info says that they are gapless, but there is a very noticeable click or pop at the song transitions.  My newer rips, which I've been re-doing using a higher bitrate over past year or two, ARE gapless on the iPod, but I don't know if this is due to the fact that they used a newer version of the LAME encoder, or the fact that they were ripped at a higher bitrate.  I'll do some testing when I get a chance to determine if a new encode at the older, previous bitrate ("Standard" VBR or 160 CBR) plays gaplessly or not.  In the mean time, I wanted to report this.

I can't be sure at this point if these same songs "used" to be gapless since most (if not all) of my tests surrounding gapless playback have been done with newer, re-ripped songs from the albums that are more important to me.

Does anyone know if there were changes in the LAME encoder MC uses that might exlplain this?  As I mentioned, the "format" info for the older rips says "Gapless: Yes," and it does contain the "start" and "end" sample info, but it still puts a noticeable click at the transition, and it seems to be consistent that "older" rips are not gapless.  Conversely, is it possible for lower bitrates to cause gapless problems on the iPod?  The lowest bitrates I've used are the "Standard" VBR setting and the 160 CBR setting.  I later switched to the "High" VBR setting for a while, then finally just went with the "Extreme" VBR setting.

Thanks for feedback on this,

Larry

[hit_ny]

might help if we know which version of lame encoder was used.

You can use lametag to get this information.

[Alex B]

All files with a LAME Info header have the same duration accuracy independently from the used bitrate. I.e. a correctly decoded LAME file should have exactly the same duration as the original source file if both files have the same sample rate (e.g. 44.1 kHz). I have often used low bitrates like 64 - 96 kbps when I have encoded files for testing gapless playback.

Something else is going on. Either the PCM source files were not gapless before encoding or the LAME headers are incorrect for some reason.

Did you use the Normalize option when you ripped the old files? That could cause the waveform to not be seamless over the track changes. I wonder (can't remember anymore) if the old MJ/MC versions had more DSP options for ripping, options like "remove silence in the beginning and end of the track". Also that kind of DSP would have produced less than perfect results.

Edit

You mentioned only iPod playback. Do the old files play gaplessly on MC?

Edit 2

Edited the first sentence.

[geekbeats2]

Not sure exactly whats going on with your problem, but I can tell you definitively that GAPLESS playeback wasnt introduced to the LAME encoder until ver. 3.92. So anything before that will not have a LAME Gapless Tag.

[hit_ny]

3.90 onwards is when i think gapless started.

[lalittle]

Something else is going on. Either the PCM source files were not gapless before encoding or the LAME headers are incorrect for some reason.

It's not the source, because the same tracks ARE gapless in MC, and if I re-rip these tracks off the same CD's they play back gaplessly on the iPod as well.  It only seems to be my "older" rips that do this, but it seems to be consistent with these older rips -- i.e. I've yet to find an "older" rip that doesn't have this problem.

Did you use the Normalize option when you ripped the old files? That could cause the waveform to not be seamless over the track changes.

No -- I didn't use normalize.  The only changes I made were 1) some of these older rips were CBR, or 2) I increased the VBR quality setting.

I wonder (can't remember anymore) if the old MJ/MC versions had more DSP options for ripping, options like "remove silence in the beginning and end of the track". Also that kind of DSP would have produced less than perfect results.

I didn't use any such settings.

You mentioned only iPod playback. Do the old files play gaplessly on MC?

Yes -- the same files play back gaplessly in MC.  It's only on the iPod that I get the pops at the transitions.

I didn't use that other program to check for the LAME version, but according to the "Format" info in MC, the files do contain the Gapless info -- i.e. they say "Gapless: Yes."  Is it possible that early versions of the LAME encoder were somehow different in this regard?  Did something about the encoder change or get updated at some point that could explain this?  It seems odd that the same songs ARE gapless in MC, but I'm definitely getting pops at transitions on the iPod that aren't there when the same CD is re-ripped.

Thanks again,

Larry

[Alex B]

Yes -- the same files play back gaplessly in MC.  It's only on the iPod that I get the pops at the transitions.

I didn't use that other program to check for the LAME version, but according to the "Format" info in MC, the files do contain the Gapless info -- i.e. they say "Gapless: Yes."  Is it possible that early versions of the LAME encoder were somehow different in this regard?  Did something about the encoder change or get updated at some point that could explain this?  It seems odd that the same songs ARE gapless in MC, but I'm definitely getting pops at transitions on the iPod that aren't there when the same CD is re-ripped.

Perhaps the Info header format is slighly different in your older MP3 files. I'd guess that the component that translates the gapless decoding info to the iPod DB format doesn't work correctly with the files. Possibly MC uses separate code for calculating the playback correction.

Since this is probably an MC problem Matt may want to have a couple of sample file pairs.