• Status Closed
  • Percent Complete
  • Task Type Bugs
  • Category Music playback
  • Assigned To No-one
  • Operating System All players
  • Severity Medium
  • Priority Very Low
  • Reported Version
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by dunno - 2006-11-13
Last edited by pondlife - 2007-07-31

FS#6326 - Gapless is borked, has artifact at track tranistion

Recently with most recent build and going back several builds I have noticed that there is a slight "bump" or artifact between track transitions with gapless albums/music.

LAME 3.90.3 –alt-preset standard

Replay Gain enabled
eq enabled

Crossfade DISABLED
Auto Change Directory DISABLED

Closed by  pondlife
2007-07-31 10:45
Reason for closing:  Not a Bug
Additional comments about closing:   Warning: Undefined array key "typography" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 371 Warning: Undefined array key "camelcase" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 407

No new input for 9 months. Reopen if it's really a problem.

dunno commented on 2006-11-13 18:20


Let the player go through the whole album as it doesn't do it with all track transitions.

Hi Joaquim,

If you get a chance, can you work backwards (or binary chop) and work out which date this problem started? I'll look into if I have time, but this would be useful info.

How are your mp3's tagged? Some programs default to adding ID3 and APE tags to mp3's (for example, older version of foobar2000, mp3tag might add both, mp3gain uses APE tags, etc.). Due to the way gapless is handled in Rockbox, the presence of APE tags at the end of mp3's will break gapless playback in cases where more than one frame needs to be trimmed.

I plan to commit a patch to strip APE tags very soon (today or tomorrow).

If you are sure your files don't have APE tags, then I'm not sure what would have changed to break gapless playback.

dunno commented on 2006-11-13 21:30

I only have ID3 V2 and V1 tags no ape tags, and player is set to V2 first then V1

dunno commented on 2006-11-13 21:33

perhaps I can send a sample of the offending tracks to someone ?

dunno commented on 2006-11-13 22:01

Hmmm, I'll be listening to a gapless album and it'll go "bump" at a track transition, I make a mental note, but trying to reproduce it at will now is proving difficult, don't know what to say, sorry to hassle you guys, I'll try to narrow it down a bit more, i.e. if the HD spins at track transition.

Many Thanks

There is definitely a timing problem in playback when entries in the track structure are re-used. Normally this will only happen after 32 tracks have played, so it's not very noticable. If you can make your own build, edit playback.h to change:
#define MAX_TRACK 32
#define MAX_TRACK 3
Doing this makea any problems in this area much more reproducible.
Might be unrelated, but might also help.

from reading the GaplessHowTo wiki page I believe you need to add the –nogap switch when encoding. Have you also tried formats that can do gapless natively (like ogg)? I haven't found gapless to be broken on my player (mostly oggs, and I don't expect mp3 to be completely gapless due to its technical reasons …)
(Side note: *if* the behaviour of lame has changed so that –nogap isn't needed anymore it would be good if someone could adjust the wiki page accordingly, optimally also telling which versions need the flag.)

–nogap is only needed on HWCODEC platforms. I believe this is stated on the wiki page, but could probably be stated more clearly. No flag is needed when encoding gapless with all recent versions of LAME.

dunno commented on 2006-11-14 20:46

Thanks for the comments.

ALL my 120gigs of music is encoded to uberstandard (without -no gap), which reccommends LAME V3.90.3 –a-p s, this version of LAME was the reccommended version by the authors of LAME until recently, V3.90.3 has been superceded by .97 or suchlikes. The reason that I mention this is that I have gotten rid of my CD's as I ripped then all to mp3, so I don't have the luxury of ripping to ogg or suchlikes, even if I did have the originals I doubt I would spend the time/energy re-ripping my whole collection…bottom line…., i'm stuck with good quality/transparent mp3.

Many thanks for all your inputs.


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