GNOME Bugzilla – Bug 794165
FLAC decoding skips on a certain file
Last modified: 2018-03-16 10:03:43 UTC
I just ripped a CD using Soundjuicer, and the generated FLAC file plays badly in Rhythmbox. Specifically, at about the 17-second mark, the song skips ahead to about the 40-second mark. I can reproduce this behavior using gst-launch-1.0 --gst-debug-level 2 --verbose filesrc location=filename.flac ! flacparse ! flacdec ! audioconvert ! audioresample ! autoaudiosink This command emits the following log messages: 0:00:17.732309329 9720 0x7f032c014ec0 WARN pulse pulsesink.c:702:gst_pulsering_stream_underflow_cb:<autoaudiosink0-actual-sink-pulse> Got underflow 0:00:17.745056358 9720 0x55eb5b3368a0 WARN audiobasesink gstaudiobasesink.c:1787:gst_audio_base_sink_get_alignment:<autoaudiosink0-actual-sink-pulse> Unexpected discontinuity in audio timestamps of +0:00:00.000022675, resyncing 0:00:17.778264650 9720 0x7f032c014ec0 WARN pulse pulsesink.c:702:gst_pulsering_stream_underflow_cb:<autoaudiosink0-actual-sink-pulse> Got underflow The exact timestamp at the beginning of the line changes each time I run the command, but the discontinuity is always the same. The file plays OK in Firefox, but maybe the file is actually corrupt and the bug is in the FLAC encoder instead. I can probably upload the FLAC somewhere if it would be helpful. I'm using gstreamer 1.12.4 on Fedora 27.
Thanks for the bug report. Any chance you could check if the patch from bug #791473 fixes it? Or make a test file available?
I have uploaded the file in question to http://dump.betacantrips.com/test-case.flac. I don't have anything set up to build gstreamer at the moment, sorry!
It can be reproduced with 1.12 (master), git master too. It's much worst with avdec_flac.
Btw, with avdec, the result is consistent with vlc, it jumps at about 18s right from the start.
I should probably also note that I tried reripping the CD on the same machine I'm playing it on (gstreamer 1.12.4) and the new file does not have the same skipping behavior. The one that I originally ripped it on was 1.12.3, so this may be due to a bug that has been fixed in 1.12.4?
Yes, there was a flacparse bug fixed between 1.12.3 and 1.12.4 that messed up the flac metadata when rewriting the header at the end.
Works as expected as that file metadata is totally broken. see https://trac.videolan.org/vlc/ticket/19968
Looks like a duplicate of bug #785558 then. Thanks! See also https://bugzilla.gnome.org/show_bug.cgi?id=792985 *** This bug has been marked as a duplicate of bug 785558 ***