Bug#713856: libavutil51: Pulseaudio provokes SIGFPE in libavutil

2013-07-13 Thread Dario Ernst 
Hey,

> I will see to backport it, which in turn should fix the crash.
That'd be just great! Please notify me as soon as a .deb is available
for installation and testing, be it in the repositories or not.

> Thanks for the bug report!
I am the one to say thanks here. Thank you a lot for offering your
expertise here!

Best Regards
- Dario


-- 
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org

Bug#713856: libavutil51: Pulseaudio provokes SIGFPE in libavutil

2013-07-12 Thread Reinhard Tartler 
On Fri, Jul 12, 2013 at 11:05 PM, Dario Ernst  wrote:
> On 07/12/2013 10:39 PM, Reinhard Tartler wrote:
>> Are you absolutely sure that you have libav-dbg installed? I would
>> really need to see the locals and the stack frame of frames #0 and #1.
>> The source of the code in question can be seen here:
>
> Actually i have to admit: i seem quite dumb! I accidentally ran the gdb
> on the wrong box again before pasting, not noticing that there were
> missing symbols in what i pasted. Sorry, thats my bad! Below is the
> (hopefully finally correct) gdb run:

Ok, that trace did indeed help me. What is missing is this patch:

http://git.libav.org/?p=libav.git;a=patch;h=0109a09dc3850eb5dbff84a7bb50eb252a5a8f22

I will see to backport it, which in turn should fix the crash.

Thanks for the bug report!

One could also argue that alsa's a52 plugin should be fixed to not
call av_samples_alloc()  with 0 as last parameter, but with 32:
http://sources.debian.net/src/alsa-plugins/1.0.27-2/a52/pcm_a52.c#L556

-- 
regards,
Reinhard


-- 
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org

Bug#713856: libavutil51: Pulseaudio provokes SIGFPE in libavutil

2013-07-12 Thread Dario Ernst 
On 07/12/2013 10:39 PM, Reinhard Tartler wrote:
> Are you absolutely sure that you have libav-dbg installed? I would
> really need to see the locals and the stack frame of frames #0 and #1.
> The source of the code in question can be seen here:

Actually i have to admit: i seem quite dumb! I accidentally ran the gdb
on the wrong box again before pasting, not noticing that there were
missing symbols in what i pasted. Sorry, thats my bad! Below is the
(hopefully finally correct) gdb run:

 daddel9/ > gdb pulseaudio
GNU gdb (GDB) 7.6-debian
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later

This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
...
Reading symbols from /usr/bin/pulseaudio...Reading symbols from
/usr/lib/debug/usr/bin/pulseaudio...done.
done.
(gdb) run
Starting program: /usr/bin/pulseaudio
warning: no loadable sections found in added symbol-file system-supplied
DSO at 0x77ffa000
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
process 6725 is executing new program: /usr/bin/pulseaudio
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
W: [pulseaudio] pid.c: Stale PID file, overwriting.

Program received signal SIGFPE, Arithmetic exception.
0x7fffeb9dc42a in av_samples_get_buffer_size
(linesize=linesize@entry=0x0, nb_channels=nb_channels@entry=6,
nb_samples=nb_samples@entry=1536,
sample_fmt=sample_fmt@entry=AV_SAMPLE_FMT_S16,
align=align@entry=0) at
/build/libav-wfhxN3/libav-0.8.7/libavutil/samplefmt.c:108
108 /build/libav-wfhxN3/libav-0.8.7/libavutil/samplefmt.c: No such
file or directory.
(gdb) bt
#0  0x7fffeb9dc42a in av_samples_get_buffer_size
(linesize=linesize@entry=0x0, nb_channels=nb_channels@entry=6,
nb_samples=nb_samples@entry=1536,
sample_fmt=sample_fmt@entry=AV_SAMPLE_FMT_S16, align=align@entry=0)
at /build/libav-wfhxN3/libav-0.8.7/libavutil/samplefmt.c:108
#1  0x7fffeb9dc5c3 in av_samples_alloc (audio_data=0x7b7b80,
linesize=0x7b7ba0, nb_channels=6, nb_samples=1536,
sample_fmt=AV_SAMPLE_FMT_S16, align=0)
at /build/libav-wfhxN3/libav-0.8.7/libavutil/samplefmt.c:143
#2  0x7fffeca7022f in ?? () from
/usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_pcm_a52.so
#3  0x7fffecc8526d in pa_alsa_set_hw_params (pcm_handle=0x78b490,
ss=ss@entry=0x7fffd290,
period_size=period_size@entry=0x7fffd280,
buffer_size=buffer_size@entry=0x7fffd288,
tsched_size=tsched_size@entry=0, use_mmap=use_mmap@entry=0x0,
use_tsched=use_tsched@entry=0x0,
require_exact_channel_number=require_exact_channel_number@entry=true)
at modules/alsa/alsa-util.c:319
#4  0x7fffecc85c77 in pa_alsa_open_by_device_string
(device=device@entry=0x7782f0 "a52:0", dev=dev@entry=0x0,
ss=ss@entry=0x7fffd290, map=map@entry=0x7fffd2a0,
mode=mode@entry=0,
period_size=period_size@entry=0x7fffd280,
buffer_size=buffer_size@entry=0x7fffd288,
tsched_size=tsched_size@entry=0, use_mmap=use_mmap@entry=0x0,
use_tsched=use_tsched@entry=0x0,

require_exact_channel_number=require_exact_channel_number@entry=true) at
modules/alsa/alsa-util.c:680
#5  0x7fffecc85f68 in pa_alsa_open_by_template (template=, dev_id=dev_id@entry=0x67b900 "0", dev=dev@entry=0x0,
ss=ss@entry=0x7fffd290, map=map@entry=0x7fffd2a0,
mode=mode@entry=0, period_size=period_size@entry=0x7fffd280,
buffer_size=buffer_size@entry=0x7fffd288,
tsched_size=tsched_size@entry=0, use_mmap=use_mmap@entry=0x0,
use_tsched=use_tsched@entry=0x0,
require_exact_channel_number=require_exact_channel_number@entry=true) at
modules/alsa/alsa-util.c:756
#6  0x7fffecc8da77 in mapping_open_pcm (m=m@entry=0x685960,
ss=ss@entry=0x61d0fc, dev_id=dev_id@entry=0x67b900 "0",
mode=mode@entry=0, default_n_fragments=default_n_fragments@entry=4,
default_fragment_size_msec=default_fragment_size_msec@entry=25) at
modules/alsa/alsa-mixer.c:4245
#7  0x7fffecc978ea in pa_alsa_profile_set_probe (ps=0x67f4e0,
dev_id=0x67b900 "0", ss=0x61d0fc, default_n_fragments=4,
default_fragment_size_msec=25) at modules/alsa/alsa-mixer.c:4330
#8  0x7fffed1b321f in module_alsa_card_LTX_pa__init (m=0x678500) at
modules/alsa/module-alsa-card.c:697
#9  0x77b7419b in pa_module_load (c=0x61cfe0,
name=name@entry=0x7fffed5ca19b "module-alsa-card",
argument=0x678be0 "device_id=\"0\" name=\"pci-_00_1b.0\"
card

Bug#713856: libavutil51: Pulseaudio provokes SIGFPE in libavutil

2013-07-12 Thread Reinhard Tartler 
On Fri, Jul 12, 2013 at 3:52 PM, Dario Ernst  wrote:
> Hello Reinhard,
>
> On 06/29/2013 08:21 AM, Reinhard Tartler wrote:
>> Can you please redo this backtrace with the packages "pulseaudio-dbg"
>> and "libav-dbg" installed? Without that, the backtrace has only
>> limited use.
>>
>> Also, please use both "bt full" and "bt" commands in the debugger.
>
> I have finally found some time to revert my libav packages to the Debian
> version from the (semi-working) DMO version. I've also installed
> pulseaudio-dbg (of pulseaudio 4.0-3). Here is the gdb output of run/bt
> and run/bt-full:
>
>
>  ~/ > gdb pulseaudio
> GNU gdb (GDB) 7.6-debian
> Copyright (C) 2013 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later
> 
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-linux-gnu".
> For bug reporting instructions, please see:
> ...
> Reading symbols from /usr/bin/pulseaudio...Reading symbols from
> /usr/lib/debug/usr/bin/pulseaudio...done.
> done.
> (gdb) run
> Starting program: /usr/bin/pulseaudio
> warning: no loadable sections found in added symbol-file system-supplied
> DSO at 0x77ffa000
> warning: Could not load shared library symbols for linux-vdso.so.1.
> Do you need "set solib-search-path" or "set sysroot"?
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
> process 16248 is executing new program: /usr/bin/pulseaudio
> warning: Could not load shared library symbols for linux-vdso.so.1.
> Do you need "set solib-search-path" or "set sysroot"?
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
> W: [pulseaudio] pid.c: Stale PID file, overwriting.
>
> Program received signal SIGFPE, Arithmetic exception.
> 0x7fffeb9dc42a in av_samples_get_buffer_size () from
> /usr/lib/x86_64-linux-gnu/libavutil.so.51
> (gdb) bt
> #0  0x7fffeb9dc42a in av_samples_get_buffer_size () from
> /usr/lib/x86_64-linux-gnu/libavutil.so.51
> #1  0x7fffeb9dc5c3 in av_samples_alloc () from
> /usr/lib/x86_64-linux-gnu/libavutil.so.51
> #2  0x7fffeca7022f in ?? () from
> /usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_pcm_a52.so
> #3  0x7fffecc8526d in pa_alsa_set_hw_params (pcm_handle=0x78b490,
> ss=ss@entry=0x7fffd2a0,
> period_size=period_size@entry=0x7fffd290,
> buffer_size=buffer_size@entry=0x7fffd298,
> tsched_size=tsched_size@entry=0, use_mmap=use_mmap@entry=0x0,
> use_tsched=use_tsched@entry=0x0,
> require_exact_channel_number=require_exact_channel_number@entry=true)
> at modules/alsa/alsa-util.c:319

Are you absolutely sure that you have libav-dbg installed? I would
really need to see the locals and the stack frame of frames #0 and #1.
The source of the code in question can be seen here:

http://sources.debian.net/src/libav/6:0.8.7-1/libavutil/samplefmt.c?hl=96#L96

I wonder what kind of FPE this could be, maybe a division by zero? but
how can that happen?

>
> I have not been able to make too much sense from that, beeing a
> higher-level guy myself, i also couldn't quite follow the codeflow in
> libavutils a52 helper functions. So i really do hope that someone of you
> can make sense of this, and either fix it or get upstream to fix it (i
> am right in that i should not open an upstream bugreport, right?).

well, upstream's input would be great to have, but they will most
certainly ask you to try the latest HEAD of the master branch. Would
you be willing (and able) to recompile the alsa ac3 encoder plugin
against a custom build libacodec? If that fixes the problem, we could
proceed with identifying what commit to backport, if not, I would
think that upstream would be quite open to assist with finding a
solution to this problem.

Cheers,
Reinhard


-- 
regards,
Reinhard


-- 
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org

Bug#713856: libavutil51: Pulseaudio provokes SIGFPE in libavutil

2013-07-12 Thread Dario Ernst 
Hello Reinhard,

On 06/29/2013 08:21 AM, Reinhard Tartler wrote:
> Can you please redo this backtrace with the packages "pulseaudio-dbg"
> and "libav-dbg" installed? Without that, the backtrace has only
> limited use.
> 
> Also, please use both "bt full" and "bt" commands in the debugger.

I have finally found some time to revert my libav packages to the Debian
version from the (semi-working) DMO version. I've also installed
pulseaudio-dbg (of pulseaudio 4.0-3). Here is the gdb output of run/bt
and run/bt-full:


 ~/ > gdb pulseaudio
GNU gdb (GDB) 7.6-debian
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later

This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
...
Reading symbols from /usr/bin/pulseaudio...Reading symbols from
/usr/lib/debug/usr/bin/pulseaudio...done.
done.
(gdb) run
Starting program: /usr/bin/pulseaudio
warning: no loadable sections found in added symbol-file system-supplied
DSO at 0x77ffa000
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
process 16248 is executing new program: /usr/bin/pulseaudio
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
W: [pulseaudio] pid.c: Stale PID file, overwriting.

Program received signal SIGFPE, Arithmetic exception.
0x7fffeb9dc42a in av_samples_get_buffer_size () from
/usr/lib/x86_64-linux-gnu/libavutil.so.51
(gdb) bt
#0  0x7fffeb9dc42a in av_samples_get_buffer_size () from
/usr/lib/x86_64-linux-gnu/libavutil.so.51
#1  0x7fffeb9dc5c3 in av_samples_alloc () from
/usr/lib/x86_64-linux-gnu/libavutil.so.51
#2  0x7fffeca7022f in ?? () from
/usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_pcm_a52.so
#3  0x7fffecc8526d in pa_alsa_set_hw_params (pcm_handle=0x78b490,
ss=ss@entry=0x7fffd2a0,
period_size=period_size@entry=0x7fffd290,
buffer_size=buffer_size@entry=0x7fffd298,
tsched_size=tsched_size@entry=0, use_mmap=use_mmap@entry=0x0,
use_tsched=use_tsched@entry=0x0,
require_exact_channel_number=require_exact_channel_number@entry=true)
at modules/alsa/alsa-util.c:319
#4  0x7fffecc85c77 in pa_alsa_open_by_device_string
(device=device@entry=0x7782f0 "a52:0", dev=dev@entry=0x0,
ss=ss@entry=0x7fffd2a0, map=map@entry=0x7fffd2b0,
mode=mode@entry=0,
period_size=period_size@entry=0x7fffd290,
buffer_size=buffer_size@entry=0x7fffd298,
tsched_size=tsched_size@entry=0, use_mmap=use_mmap@entry=0x0,
use_tsched=use_tsched@entry=0x0,

require_exact_channel_number=require_exact_channel_number@entry=true) at
modules/alsa/alsa-util.c:680
#5  0x7fffecc85f68 in pa_alsa_open_by_template (template=, dev_id=dev_id@entry=0x67b900 "0", dev=dev@entry=0x0,
ss=ss@entry=0x7fffd2a0, map=map@entry=0x7fffd2b0,
mode=mode@entry=0, period_size=period_size@entry=0x7fffd290,
buffer_size=buffer_size@entry=0x7fffd298,
tsched_size=tsched_size@entry=0, use_mmap=use_mmap@entry=0x0,
use_tsched=use_tsched@entry=0x0,
require_exact_channel_number=require_exact_channel_number@entry=true) at
modules/alsa/alsa-util.c:756
#6  0x7fffecc8da77 in mapping_open_pcm (m=m@entry=0x685960,
ss=ss@entry=0x61d0fc, dev_id=dev_id@entry=0x67b900 "0",
mode=mode@entry=0, default_n_fragments=default_n_fragments@entry=4,
default_fragment_size_msec=default_fragment_size_msec@entry=25) at
modules/alsa/alsa-mixer.c:4245
#7  0x7fffecc978ea in pa_alsa_profile_set_probe (ps=0x67f4e0,
dev_id=0x67b900 "0", ss=0x61d0fc, default_n_fragments=4,
default_fragment_size_msec=25) at modules/alsa/alsa-mixer.c:4330
#8  0x7fffed1b321f in module_alsa_card_LTX_pa__init (m=0x678500) at
modules/alsa/module-alsa-card.c:697
#9  0x77b7419b in pa_module_load (c=0x61cfe0,
name=name@entry=0x7fffed5ca19b "module-alsa-card",
argument=0x678be0 "device_id=\"0\" name=\"pci-_00_1b.0\"
card_name=\"alsa_card.pci-_00_1b.0\" namereg_fail=false tsched=yes
fixed_latency_range=no ignore_dB=no deferred_volume=yes use_ucm=yes
card_properties=\"module-u"...) at pulsecore/module.c:115
#10 0x7fffed5c8a37 in verify_access (u=0x6749b0, d=0x6783f0) at
modules/module-udev-detect.c:341
#11 0x7fffed5c9cb7 in process_path (path=,
u=0x6749b0) at modules/module-udev-detect.c:489
#12 module_udev_detect_LTX_pa__init (m=) at
modules/module-udev-detect.c:797
#13 0x77b7419b in pa_module_load (c=c@entry=0x61cfe0,
name=name@entry=0x624ac0 "m

Bug#713856: libavutil51: Pulseaudio provokes SIGFPE in libavutil

2013-07-04 Thread Dario Ernst 
Hello,


On 06/29/2013 08:21 AM, Reinhard Tartler wrote:
> Can you please redo this backtrace with the packages "pulseaudio-dbg"
> and "libav-dbg" installed? Without that, the backtrace has only
> limited use.
> 
> Also, please use both "bt full" and "bt" commands in the debugger.

Thanks for your reply and assistance/clearification. I'm currently quite
busy with university, so i have a little lag doing this small
experiment. I will take a few more todays, but i should have time this
weekend.

Sorry for the delay, and thanks for your concern.
- Dario Ernst


-- 
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org

Bug#713856: libavutil51: Pulseaudio provokes SIGFPE in libavutil

2013-06-28 Thread Reinhard Tartler 
tags 713856 moreinfo upstream
severity 713856 normal
stop

On Sun, Jun 23, 2013 at 11:29 AM, Dario Ernst  wrote:

> Digging deeper with gdb, you might get:
> =
>  ~/ > gdb pulseaudio
> [...]
> (gdb) run
> Starting program: /usr/bin/pulseaudio
> warning: no loadable sections found in added symbol-file system-supplied
> DSO at 0x77ffa000
> warning: Could not load shared library symbols for linux-vdso.so.1.
> Do you need "set solib-search-path" or "set sysroot"?
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
> process 12005 is executing new program: /usr/bin/pulseaudio
> warning: Could not load shared library symbols for linux-vdso.so.1.
> Do you need "set solib-search-path" or "set sysroot"?
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
> W: [pulseaudio] pid.c: Stale PID file, overwriting.
>
> Program received signal SIGFPE, Arithmetic exception.
> 0x7fffeb7d842a in av_samples_get_buffer_size () from
> /usr/lib/x86_64-linux-gnu/libavutil.so.51
> (gdb) bt
> #0  0x7fffeb7d842a in av_samples_get_buffer_size () from
> /usr/lib/x86_64-linux-gnu/libavutil.so.51
> #1  0x7fffeb7d85c3 in av_samples_alloc () from
> /usr/lib/x86_64-linux-gnu/libavutil.so.51
> #2  0x7fffec86c22f in ?? () from
> /usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_pcm_a52.so
> #3  0x7fffecd22eef in ?? () from
> /usr/lib/x86_64-linux-gnu/libasound.so.2
> #4  0x7fffeca8154d in pa_alsa_set_hw_params () from
> /usr/lib/pulse-4.0/modules/libalsa-util.so
> #5  0x7fffeca81c77 in pa_alsa_open_by_device_string () from
> /usr/lib/pulse-4.0/modules/libalsa-util.so
> #6  0x7fffeca81f68 in pa_alsa_open_by_template () from
> /usr/lib/pulse-4.0/modules/libalsa-util.so
> #7  0x7fffeca89a77 in ?? () from
> /usr/lib/pulse-4.0/modules/libalsa-util.so
> #8  0x7fffeca938ea in pa_alsa_profile_set_probe () from
> /usr/lib/pulse-4.0/modules/libalsa-util.so
> #9  0x7fffecfaf21f in module_alsa_card_LTX_pa__init () from
> /usr/lib/pulse-4.0/modules/module-alsa-card.so
> #10 0x77b7419b in pa_module_load () from
> /usr/lib/libpulsecore-4.0.so
> #11 0x7fffed3c4a37 in ?? () from
> /usr/lib/pulse-4.0/modules/module-udev-detect.so
> #12 0x7fffed3c5cb7 in module_udev_detect_LTX_pa__init () from
> /usr/lib/pulse-4.0/modules/module-udev-detect.so
> #13 0x77b7419b in pa_module_load () from
> /usr/lib/libpulsecore-4.0.so
> #14 0x77b6372a in ?? () from /usr/lib/libpulsecore-4.0.so
> #15 0x77b69282 in pa_cli_command_execute_line_stateful () from
> /usr/lib/libpulsecore-4.0.so
> #16 0x77b69b91 in pa_cli_command_execute_file_stream () from
> /usr/lib/libpulsecore-4.0.so
> #17 0x0040796e in main ()

Can you please redo this backtrace with the packages "pulseaudio-dbg"
and "libav-dbg" installed? Without that, the backtrace has only
limited use.

Also, please use both "bt full" and "bt" commands in the debugger.

Thanks for your assistance.


-- 
regards,
Reinhard


-- 
To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org

Bug#713856: libavutil51: Pulseaudio provokes SIGFPE in libavutil

2013-06-23 Thread Dario Ernst 
Package: libavutil51
Version: 6:0.8.7-1
Severity: important
Tags: upstream

Dear Maintainer,
*** Please consider answering these questions, where appropriate ***

   * What led up to the situation?
   * What exactly did you do (or not do) that was effective (or
 ineffective)?
   * What was the outcome of this action?
   * What outcome did you expect instead?

*** End of the template - remove these lines ***

I am using pulseaudio (tried 2.0-6.1 and 4.0-3) for my sound output via
digital surround S/PDIF using A52 encoding. This is achieved by
pulseaudio relying on libasound2-plugins encoder which in turn relies on
libav (as far as i can understand). After a recent testing (my current
debian version) upgrade pulseaudio began not to start anymore, and
exiting with a SIGFPE, Arithmetic exception. This can
(probably/hopefully) be reproduced the following way:

Install pulseaudio and its libav dependencies from unstable on a
computer with a S/PDIF output that can/could be used by alsa. Put the
following in /etc/asound.conf:
=
pcm.a52 {
  @args [CARD]
  @args.CARD {
type string
  }
  type rate
  slave {
pcm {
  type a52
  bitrate 448
  channels 6
  card $CARD
}
rate 48000 #required somehow, otherwise nothing happens in PulseAudio
  }
}
=
and then starting pulseaudio:
 ~/ > pulseaudio
W: [pulseaudio] pid.c: Stale PID file, overwriting.
Floating point exception

Digging deeper with gdb, you might get:
=
 ~/ > gdb pulseaudio
[...]
(gdb) run
Starting program: /usr/bin/pulseaudio
warning: no loadable sections found in added symbol-file system-supplied
DSO at 0x77ffa000
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
process 12005 is executing new program: /usr/bin/pulseaudio
warning: Could not load shared library symbols for linux-vdso.so.1.
Do you need "set solib-search-path" or "set sysroot"?
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
W: [pulseaudio] pid.c: Stale PID file, overwriting.

Program received signal SIGFPE, Arithmetic exception.
0x7fffeb7d842a in av_samples_get_buffer_size () from
/usr/lib/x86_64-linux-gnu/libavutil.so.51
(gdb) bt
#0  0x7fffeb7d842a in av_samples_get_buffer_size () from
/usr/lib/x86_64-linux-gnu/libavutil.so.51
#1  0x7fffeb7d85c3 in av_samples_alloc () from
/usr/lib/x86_64-linux-gnu/libavutil.so.51
#2  0x7fffec86c22f in ?? () from
/usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_pcm_a52.so
#3  0x7fffecd22eef in ?? () from
/usr/lib/x86_64-linux-gnu/libasound.so.2
#4  0x7fffeca8154d in pa_alsa_set_hw_params () from
/usr/lib/pulse-4.0/modules/libalsa-util.so
#5  0x7fffeca81c77 in pa_alsa_open_by_device_string () from
/usr/lib/pulse-4.0/modules/libalsa-util.so
#6  0x7fffeca81f68 in pa_alsa_open_by_template () from
/usr/lib/pulse-4.0/modules/libalsa-util.so
#7  0x7fffeca89a77 in ?? () from
/usr/lib/pulse-4.0/modules/libalsa-util.so
#8  0x7fffeca938ea in pa_alsa_profile_set_probe () from
/usr/lib/pulse-4.0/modules/libalsa-util.so
#9  0x7fffecfaf21f in module_alsa_card_LTX_pa__init () from
/usr/lib/pulse-4.0/modules/module-alsa-card.so
#10 0x77b7419b in pa_module_load () from
/usr/lib/libpulsecore-4.0.so
#11 0x7fffed3c4a37 in ?? () from
/usr/lib/pulse-4.0/modules/module-udev-detect.so
#12 0x7fffed3c5cb7 in module_udev_detect_LTX_pa__init () from
/usr/lib/pulse-4.0/modules/module-udev-detect.so
#13 0x77b7419b in pa_module_load () from
/usr/lib/libpulsecore-4.0.so
#14 0x77b6372a in ?? () from /usr/lib/libpulsecore-4.0.so
#15 0x77b69282 in pa_cli_command_execute_line_stateful () from
/usr/lib/libpulsecore-4.0.so
#16 0x77b69b91 in pa_cli_command_execute_file_stream () from
/usr/lib/libpulsecore-4.0.so
#17 0x0040796e in main ()
=


The versions of related programs and libraries where this happens for me
are:
libasound2-plugins 1.0.27-2
libavcodec53 6:0.8.7-1
libavutil51 6:0.8.7-1
pulseaudio 4.0-3 || 2.0-6.1

I hope the provided information is sufficient to reproduce and/or
isolate the bug. By the way, one pulseaudio developer in IRC suggested
to report the bug to either alsa-plugins or libav upstream.

If anything more is needed, please tell me what. Thanks for your great
work, and Best Regards
- Dario Ernst


-- System Information:
Debian Release: jessie/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.8-trunk-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libavutil51 depends on:
ii  libc6  2