GNOME Bugzilla – Bug 670664
Gapless playback doesn't work
Last modified: 2012-03-17 18:09:57 UTC
Originally reported at: https://bugs.launchpad.net/bugs/935762 In Ubuntu 11.10, Banshee doesn't support gapless playback very well. It has an option in the preferences that claims to enable the feature, but it simply doesn't. With AAC and MP3, this is due to a format limitation. In those formats, the frame length is fixed, and so the last frame has some silence at the end, causing a slight gap. Several encoders, like LAME and Nero AAC, have implemented a tag that stores the correct track length in milliseconds. However, Banshee ignores this metadata, introducing the small gap at the end of each track. With FLAC, this shouldn't be an issue. However, there's an even larger and more noticeable gap between FLAC songs. Steps to reproduce: 1. Cue two or more gapless songs, such as those on side B of Abbey Road by The Beatles. 2. Play both songs in the correct order. 3. Observe the gap. This bug was already marked as fixed in this Launchpad around 2006, but it's clearly not.
https://bugs.launchpad.net/ubuntu/+source/banshee/+bug/935762/+attachment/2773700/+files/The%20Beatles%20-%20Polythene%20Pam%20and%20Bathroom%20Window.tar.bz2 is a tarball containing two sample flac files that do not have trailing/leading gaps in them, but are not played gapless by Banshee.
Sounds like a duplicate of: https://bugzilla.gnome.org//show_bug.cgi?id=647975 However it seems that certain gstreamer versions have broken gapless playback for flac files, please ensure that your distribution does not ship one of these: https://bugzilla.gnome.org/show_bug.cgi?id=649474
Exactly which versions are affected? On Ubuntu we have 0.10.30 and 0.10.31 on Oneiric and Precise respectively.
I do hear a gap with the files linked above. Bug #647975 depends on bug #661202, which is fixed only in gst-plugins-base 0.10.36, and on bug #661215, which is fixed only in gst-plugins-good 0.10.31. So it looks like Ubuntu 11.10 does ship versions which have those bugs. Could anyone with those GStreamer versions confirm the fix using the files provided above ?
Right, it looks like we have 0.10.35. This should be fixed in Ubuntu 12.04 then.
I installed gstreamer plugins 0.10.36 from the gstreamer-developers PPA under Oneiric, and it seems to have fixed the problem for FLAC files. However, the aforementioned problem with M4A files still exists, and that's due to either gstreamer or banshee ignoring the track length metadata.
Banshee relies entirely on GStreamer for gapless playback, and doesn't do anything specific for that depending on the file format. So the issue with M4A file is probably in GStreamer. If they are encoded with a lossy codec, gapless playback might not be possible. See: http://en.wikipedia.org/wiki/Gapless_playback#Causes_of_gaps So I'm closing this as NOTNGNOME, as the problem is not with Banshee. Feel free to reopen if you think Banshee is doing something wrong, or file a new bug with GStreamer.