[pulseaudio-discuss] Crash in LFE filter if soxr resampler is used

[Andrey Semashev]

Hi,

I've just upgraded to Kubuntu 15.10 and applied patches for libsoxr 
resampler to PA 6.0 that comes with the distro. I'm seeing crashes in 
the LFE filter if I use soxr-vhq resampler (I haven't tried the other 
soxr* variants yet). Is this a known problem? Below is the backtrace of 
one of the crashes.

Program received signal SIGABRT, Aborted.
[Switching to Thread 0x7f92bf7fc700 (LWP 2769)]
0x00007f92d2263267 in __GI_raise (sig=sig at entry=6) at 
../sysdeps/unix/sysv/linux/raise.c:55
55      ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  0x00007f92d2263267 in __GI_raise (sig=sig at entry=6) at 
../sysdeps/unix/sysv/linux/raise.c:55
#1  0x00007f92d2264eca in __GI_abort () at abort.c:89
#2  0x00007f92d37e8b8b in pa_xmalloc () from 
/usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-6.0.so
#3  0x00007f92d37e8d79 in pa_xmemdup () from 
/usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-6.0.so
#4  0x00007f92d3a60c65 in pa_lfe_filter_process (f=0x1ed1d60, 
buf=buf at entry=0x203ca50) at pulsecore/filter/lfe-filter.c:132
#5  0x00007f92d3a7e923 in pa_resampler_run (r=0x203c8d0, 
in=0x7f92bf7f9490, out=0x7f92bf7f94b0) at pulsecore/resampler.c:1384
#6  0x00007f92d3a896e3 in pa_sink_input_peek (i=i at entry=0x1ebe8d0, 
slength=22008, chunk=chunk at entry=0x7f92bf7f96d0, 
volume=volume at entry=0x7f92bf7f96e8) at pulsecore/sink-input.c:965
#7  0x00007f92d3a91fa0 in fill_mix_info (s=s at entry=0x1e36350, 
length=length at entry=0x7f92bf7f9618, info=info at entry=0x7f92bf7f96d0, 
maxinfo=32) at pulsecore/sink.c:1016
#8  0x00007f92d3a94d5d in pa_sink_render_into (s=s at entry=0x1e36350, 
target=target at entry=0x7f92bf7fbd20) at pulsecore/sink.c:1256
#9  0x00007f92d3a952ff in pa_sink_render_into_full (s=0x1e36350, 
target=target at entry=0x7f92bf7fbde0) at pulsecore/sink.c:1340
#10 0x00007f92cccf71ba in mmap_write (on_timeout=false, polled=false, 
sleep_usec=<synthetic pointer>, u=0x1fc6f60) at modules/alsa/alsa-sink.c:645
#11 thread_func (userdata=0x1fc6f60) at modules/alsa/alsa-sink.c:1716
#12 0x00007f92d38228b8 in ?? () from 
/usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-6.0.so
#13 0x00007f92d2d136aa in start_thread (arg=0x7f92bf7fc700) at 
pthread_create.c:333
#14 0x00007f92d2334eed in clone () at 
../sysdeps/unix/sysv/linux/x86_64/clone.S:109

The crashes stop happening if I disable the filter in daemon.conf with 
"enable-lfe-remixing = no".

I realise 6.0+soxr is not an official configuration, but the patches are 
a rather straightforward backport of the code that is in master, so I 
suspect the same problem will be present in 7.x. If needed, I can 
provide the actual patch I'm using.