Discussion:
[LAU] death by ogg vorbis
Paul Davis
2018-11-06 19:29:51 UTC
Permalink
strange problem ... looking for clues.

we have a slimdevices/logitech media server, and have had for more than a
decade. we have 2 or 3 playout devices, one class and two "receivers". the
system has worked solidly for a very long time.

about a month ago, i download some awesome new London jazz from a project
named Yuseef Kamal, as FLAC from Bandcamp. Sadly the project has since
broken up, but "Black Focus" is phenomenal.

As I usually do with FLAC or WAV downloads, I stash these files outside our
music repository, convert to a lossy compressed format and then move the
result into the music repository to keep the space down when we copy the
whole thing to an SD card or whatever. The compressed format is generally
always Ogg/Vorbis.

So I did the same. Played the result on my main working computer (one
version of the repo), and on my laptop (another rsync'ed copy of the repo).
Entirely expectedly, it works normally.

But then, after a lot of head scratching, I realized that whenever I try to
play any of these files via the slimdevices/logitech server+devices, it
does something to the server and/or the devices that requires a complete
reset of the entire system. Switching to other music will not work - things
are dead, even though they are superficially alive. I have never seen this
behaviour from any other music/files.

I can play the same files via some other media app on the computer where
the server runs, and there are no problems.

I've repeated this "experiment" at least 4 times so far. Playing a single
track from the Yuseef Kamal album effectively crashes my
logitech/squeezebox system (though the server is still responsive and the
controller(s) still appear to do stuff. I've tried looking a debug logs
fromthe server, but have seen nothing to indicate what is happening. I even
reconverted from the original FLAC files, and tried those instead. No
difference in the behavior.

I have a few thoughts about things to try, but wanted to see if anyone else
had any suggestions on approaches to the problem, things to look for, etc.
Will Godfrey
2018-11-06 19:38:37 UTC
Permalink
On Tue, 6 Nov 2018 14:29:51 -0500
Post by Paul Davis
strange problem ... looking for clues.
we have a slimdevices/logitech media server, and have had for more than a
decade. we have 2 or 3 playout devices, one class and two "receivers". the
system has worked solidly for a very long time.
I have a few thoughts about things to try, but wanted to see if anyone else
had any suggestions on approaches to the problem, things to look for, etc.
Just something to narrow it down a bit.

Does the same thing happen if you convert the flac into an mp3 file?
Also, what about different ogg quality settings.
--
Will J Godfrey
http://www.musically.me.uk
Say you have a poem and I have a tune.
Exchange them and we can both have a poem, a tune, and a song.
Jeanette C.
2018-11-06 20:03:10 UTC
Permalink
Nov 6 2018, Paul Davis has written:
...
Post by Paul Davis
I have a few thoughts about things to try, but wanted to see if anyone else
had any suggestions on approaches to the problem, things to look for, etc.
...
In addition to Will's suggestions: can you play other OGGs? Is there a
difference in quality, samplerate and original bit depth?
Furthermore, it's been a while since I worked with the Slimdevices, but
don't they come with a separate coopy of decoding tools? Maybe
exchanging your slimdevices copy of oggdec or whatever could help?
How about tags in the file? Different character sets perhaps?
Unlikely: but how about the health of the drive and your RAM? I know,
really unlikely with your tests.

Best wishes,

Jeanette
--
* Website: http://juliencoder.de - for summer is a state of sound
* SoundCloud: https://soundcloud.com/jeanette_c
* Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g
* GitHub: https://github.com/jeanette-c
* Twitter: https://twitter.com/jeanette_c_s

I thought love was just a tingling of the skin <3
(Britney Spears)
Len Ovens
2018-11-06 20:10:12 UTC
Permalink
Post by Jeanette C.
...
Post by Paul Davis
I have a few thoughts about things to try, but wanted to see if anyone else
had any suggestions on approaches to the problem, things to look for, etc.
...
How about tags in the file? Different character sets perhaps?
Charactor sets have made audio files unplayable for me in the past. In
particular some Irish music as happens. I also remove spaces in file names
though that should not be needed for an audio server, it is for some of
the things I do. Though to be honest bad charactor sets have just made
those songs not show up in the list rather than freezing things.


--
Len Ovens
www.ovenwerks.net
Paul Davis
2018-11-06 20:10:57 UTC
Permalink
Post by Jeanette C.
...
Post by Paul Davis
I have a few thoughts about things to try, but wanted to see if anyone
else
Post by Paul Davis
had any suggestions on approaches to the problem, things to look for,
etc.
...
In addition to Will's suggestions: can you play other OGGs? Is there a
difference in quality, samplerate and original bit depth?
We have about 15,500 files in our music repo, of which about 2/3 are
ogg/vorbis that I generated myself. They all work. In addition, other
ogg/vorbis files generated from FLAC obtained from bandcamp both before and
after the "Black Focus" album work just fine.
Chris Cannam
2018-11-06 20:11:21 UTC
Permalink
Post by Paul Davis
I've repeated this "experiment" at least 4 times so far. Playing a single
track from the Yuseef Kamal album effectively crashes my
logitech/squeezebox system
When you say "a single track", do you mean a particular track (e.g. the first) or any track from the album?

I know that the name Yusuf Kamaal appears on the cover in the Arabic alphabet as باستكمال as well as in the Roman alphabet. Is it possible the track metadata also has right-to-left text in some field?


Chris
Chris Cannam
2018-11-06 20:16:46 UTC
Permalink
Post by Chris Cannam
I know that the name Yusuf Kamaal appears on the cover in the Arabic
alphabet as باستكمال
Death-by-autocorrect in Arabic there! I typed يوسفكمال - honest - but the first word apparently got autocorrected.


Chris
David Kastrup
2018-11-06 20:17:50 UTC
Permalink
Post by Chris Cannam
Post by Paul Davis
I've repeated this "experiment" at least 4 times so far. Playing a single
track from the Yuseef Kamal album effectively crashes my
logitech/squeezebox system
When you say "a single track", do you mean a particular track
(e.g. the first) or any track from the album?
I know that the name Yusuf Kamaal appears on the cover in the Arabic
alphabet as باستكمال as well as in the Roman alphabet. Is it possible
the track metadata also has right-to-left text in some field?
You mean, some column or character counts might be confused with byte
counts?

Perhaps running with

LC_CTYPE=C ...

would make a difference then? Or something corresponding to Latin-1
rather than UTF-8?
--
David Kastrup
Chris Cannam
2018-11-06 20:25:07 UTC
Permalink
Anything interesting in that "visit..." URL field?


Chris
Paul Davis
2018-11-06 20:32:13 UTC
Permalink
Post by Chris Cannam
Anything interesting in that "visit..." URL field?
i just checked that, and it's the URL for their bandcamp page. i compared
to another recent FLAC/bandcamp download, and the only difference seems to
be the URL
Chris Cannam
2018-11-06 20:36:04 UTC
Permalink
Post by Paul Davis
i just checked that, and it's the URL for their bandcamp page. i compared
to another recent FLAC/bandcamp download, and the only difference seems to
be the URL
Metadata still seems like the most obvious thing, though, especially if your player has oldish software. You converted from FLAC which presumably kept the metadata - how about stripping it, e.g. by encoding again via WAV (or using a metadata editing tool, but I guess you might not be certain you'd caught everything)


Chris
Paul Davis
2018-11-06 20:41:44 UTC
Permalink
Post by Chris Cannam
Post by Paul Davis
i just checked that, and it's the URL for their bandcamp page. i compared
to another recent FLAC/bandcamp download, and the only difference seems
to
Post by Paul Davis
be the URL
Metadata still seems like the most obvious thing, though, especially if
your player has oldish software. You converted from FLAC which presumably
kept the metadata - how about stripping it, e.g. by encoding again via WAV
(or using a metadata editing tool, but I guess you might not be certain
you'd caught everything)
that's a good idea. i'll give that a try.
David Runge
2018-11-07 07:30:28 UTC
Permalink
Post by Paul Davis
that's a good idea. i'll give that a try.
If it's indeed related to the metadata/tags, I can recommend using
software such as musicbrainz picard [1] to add nice tags to your lossy
(or lossless) files. YMMV depending on your artist.

IIRC flac also uses a different tag standard from the one in use in mp3
or ogg.

Best,
David

[1] https://picard.musicbrainz.org/
--
https://sleepmap.de
Chris Caudle
2018-11-08 16:14:42 UTC
Permalink
Post by Paul Davis
play any of these files via the slimdevices/logitech server+devices, it
does something to the server and/or the devices that requires a complete
reset of the entire system.
Can you post the output of ogginfo -v for the file which crashes your
players?
There is a software player called squeezelite that runs under linux and
can emulate a squeezebox player on the network, that may be useful to
determine whether it is a firmware bug in the players crashing when it
gets either audio data or metadata that it can't handle.

I don't remember if you said which models of players you used, are they
the older style classic players using a traditional low level firmware
style design, or the newer style in the Radio which is running on embedded
linux? If you have both available that might give another datapoint if
the old style player crashes but the new one does not, or the opposite.
--
Chris Caudle
Paul Davis
2018-11-11 22:29:14 UTC
Permalink
So, an update ... I don't have time to dig into this 100%, but I removed
all the metadata from the vorbis files, then retagged them by hand using
puddletag. The results work just fine.

I did notice that the files generated by soundconverter include a
METADATA_BLOCK_PICTURE field, but I have other stuff that I bought from
Bandcamp where the .ogg files also have this field/data and they did not
cause any issues.

I can now play Yuseef Kamaal on the Logitech/Squeezebox system, and because
I have a million other things to do, I'm happy and will leave it there.

Thanks for all the suggestions.
Post by Chris Caudle
Post by Paul Davis
play any of these files via the slimdevices/logitech server+devices, it
does something to the server and/or the devices that requires a complete
reset of the entire system.
Can you post the output of ogginfo -v for the file which crashes your
players?
There is a software player called squeezelite that runs under linux and
can emulate a squeezebox player on the network, that may be useful to
determine whether it is a firmware bug in the players crashing when it
gets either audio data or metadata that it can't handle.
I don't remember if you said which models of players you used, are they
the older style classic players using a traditional low level firmware
style design, or the newer style in the Radio which is running on embedded
linux? If you have both available that might give another datapoint if
the old style player crashes but the new one does not, or the opposite.
--
Chris Caudle
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