Gapless not working for iTunes encoded mp3

[Shizknight]

I've tested on build 820 and on the last build of v2.  Originally I purchased Poweramp as it was one of the few android music apps available that properly handled gapless playback.  At the time I was ripping all my music in iTunes and Apple had their own way of working out how to do gapless with mp3.  

In every version of v2 up to and including the last that I've tried, Poweramp perfectly handles itunes style gapless mp3 files.  

V3 builds I've tried, up to and including 820 do not handle it and when looking at the info/tags you can see that it's not recognizing these files as gapless.

I've spent some time verifying that these are indeed gapless according to the itunes spec.  The files I've got include the extended tag comments(specifically ITUNSMBP comment tags that contain gap and delay timing).

I moved on after iTunes to musicbee, and with that first moved to mp3s encoded with LAME.  In the last few years I've switched over to FLAC.  

I have tested and both LAME encoded gapless mp3 and gapless FLAC works as expected in build 820.

It's only iTunes MP3 gapless files that are not working for me.  

 

 

[andrewilley]

You'd need to upload a few samples (ideally adjacent tracks which join badly).

Andre

[Shizknight]

I can do that.  Where would you like them uploaded?  I'd attach to the post but the size limit prevents that.  

[andrewilley]

Any file sharing option that offers public access (Dropbox, Google, etc)

Andre

[Shizknight]

Here you go.  https://drive.google.com/open?id=1Tlul_6xaoQot4tiiKKBi2koe2rAkjFKi

This is the first two tracks of BTBAM's Great Misdirect.  

[andrewilley]

Well there is a brief period of near silence at the end of the first track (0.050) and also at the start of the second (0.023). Enough to be audible if you played them back to back anyway.

Andre

[Shizknight]

That would be expected.  You need to read the extended comment tag ITUNSMBP to gather the delay and gap data, which is then compensated for during playback.  This worked in v2 but does not in v3 so I suspect it was just missed.  Lame encoded mp3s I believe also have silences like that, but the data needed to properly play back is instead carried in the xing header.  I'm guessing that when moving from v2 to v3, gapless handling was rewritten and the itunes style of gapless info handling was just missed.  

I suppose it's also possible itunes style gapless mp3 support was removed from the app on purpose.  If that's the case I need to move myself to a new app because I don't want to go through over 1000 discs and re-rip the gapless ones.

 

[andrewilley]

31 minutes ago, Shizknight said:

You need to read the extended comment tag ITUNSMBP to gather the delay and gap data, which is then compensated for during playback.  This worked in v2 but does not in v3 so I suspect it was just missed.

I don't think so. v2 had an optional feature to cut any digital silence at the start and end of tracks for better gapless playback though, which does not seem to be implemented in v3.

Have you tried increasing the pre-read buffer size by the way?

Andre

[Shizknight]

I'm aware of the cut silence feature, and never used it.  I rolled back to the last build of v2 just to verify for sure recently and made absolutely sure cut silence was turned off in settings.  

I am absolutely positive if you try these in the last build of v2 you'll find they play gapless perfectly without cut silence turned on.  

Pre-read buffer won't make a difference here as v3 isn't currently considering these gapless.  I don't have access to the code, but I'm pretty well positive that v2 supported the ITUNSMBP tag while v3 currently doesn't.