(gdb) bt
#0  0x0053e7a2 in _dl_sysinfo_int80 () from /lib/ld-linux.so.2
#1  0x0057e7d5 in raise () from /lib/tls/libc.so.6
#2  0x00580149 in abort () from /lib/tls/libc.so.6
#3  0x00577db1 in __assert_fail () from /lib/tls/libc.so.6
#4  0x00981dcc in switch_core_codec_decode (codec=0x6, other_codec=0xb66ff2b0, encoded_data=0x0, encoded_data_len=0,
    encoded_rate=8000, decoded_data=0x7992, decoded_data_len=0x9b207ec, decoded_rate=0x9b207f8, flag=0xb65fb3b8)
    at src/switch_core.c:747
#5  0x00983410 in switch_core_session_read_frame (session=0x9b1f6d8, frame=0xb65fb418, timeout=-1, stream_id=0)
    at src/switch_core.c:1629
#6  0x0037bce2 in input_thread_run (thread=0x9b22490, obj=0xb66ff280) at mod_conference.c:2534
#7  0x00f303c8 in dummy_worker (opaque=0x0) at threadproc/unix/thread.c:138
#8  0x006c5341 in start_thread () from /lib/tls/libpthread.so.0
#9  0x0061e6fe in clone () from /lib/tls/libc.so.6