HydrogenAudio

Lossless Audio Compression => FLAC => Topic started by: SiEntomologist on 2018-12-21 08:48:32

Title: FLAC static, dropouts only at higher compression levels
Post by: SiEntomologist on 2018-12-21 08:48:32
I am convinced this is a bug in flac.exe used by FB v1.4.1, but I'm not sure where best to complain.  Over a number of years I have successfully ripped thousands of tracks from hundreds of audio cds to FLAC using FB, but recently ran into a single track that FB reported as successful but which on playback contains static and dropouts only at certain FLAC compression levels.

The track in question is a three minute track out of ten tracks coming from a disc with no signs of physical problems (no messages, no signs of retries, nothing visible on the disc, the track plays just fine from the cd).  On playback by FB at FLAC (initially version 1.2.1) level 8, a few seconds of static followed by a 45 second dropout occurred midway.  Foobar continued as though playing silence and eventually recovered, apparently playing the last seconds as it should have.  I tried ripping again with compression levels 7 down to 0; all but levels 6 and 8 seemed to play back correctly.  Compression level 6 and 8 errors were similar but at different locations.

FB was already 1.4.1, but I reinstalled it anyway.  Whenever I had originally installed FB, I had manually installed FLAC and other files, and apparently the FB reinstallation preserved the old component file locations, so I deleted the old version of flac.exe and FB asked for its location when I tried to rip the track again.  I downloaded Free_Encoder_Pack_2018-10-19.exe and let it do its thing, and it installed flac.exe in a subfolder of Program Files (x86)\foobar.  Its date indicates flac.exe is now version 1.3.2.  I don't see anywhere in FB to confirm this otherwise.  I tried my experiments again, with similar (but not identical) results except the problem was now with compression levels 7 and 8 only; levels 0 through 6 seemed to be ok.  I retried the offending tracks and got apparently identical failures for the same compression level.  The file sizes for those with dropouts are significantly smaller than the others as though actually playing silence.

I have no objection to using a lower compression level, but there could be other artifacts I didn't notice.

So my questions are, first, is there any way to confirm exactly which versions of flac.exe and other external components are being used?  (I don't see anything in Help where version levels appear for some things, for example.)  In this case, similar problems occurred with two versions, so that's not so important.  Second, are there any preference settings that might somehow affect this?  And third, where is the best place to report an apparent bug in FLAC?  xiph.org seems to be somehow responsible for it, but I don't see an obvious support forum.

Thanks.

Title: Re: FLAC static, dropouts only at higher compression levels
Post by: m14u on 2018-12-21 09:31:54
try last standalone version of flac (from rarewares);
try rip this track in wav and use flac from CLI;
delete settings from string in FB encoder-settings and manually write them again;
try eac...
Title: Re: FLAC static, dropouts only at higher compression levels
Post by: includemeout on 2018-12-21 13:19:37
Assuming no DSP is involved in the process , I'd also try encoding the same track to Wavpack or TAK,  just to so you can either confirm or rule out FLAC as the main culprit.
Title: Re: FLAC static, dropouts only at higher compression levels
Post by: Rollin on 2018-12-21 15:15:09
where is the best place to report an apparent bug in FLAC?
https://sourceforge.net/p/flac/bugs/
Title: Re: FLAC static, dropouts only at higher compression levels
Post by: lvqcl on 2018-12-21 16:52:58
Also https://github.com/xiph/flac
Title: Re: FLAC static, dropouts only at higher compression levels
Post by: Case on 2018-12-22 08:21:24
If you don't want to register on new sites you could also share the source file that acts up here. The forum rules forbid linking tracks longer than 30 seconds but you could PM me a link. If I can reproduce the problem I can try fixing it.