divide-by-zero in main (amrenc.c)

[asarubbo]

On 0.5.3:

# amrenc $FILE out.amr
===================================================================
 3GPP AMR Floating-point Speech Encoder  REL-7 V7.0.0 2007-06      
===================================================================
ASAN:DEADLYSIGNAL
=================================================================
==24102==ERROR: AddressSanitizer: FPE on unknown address 0x000000508bc7 (pc 0x000000508bc7 bp 0x7ffcecf32a40 sp 0x7ffcecf32980 T0)
    #0 0x508bc6 in main /tmp/amrenc/amrenc.c:155:33
    #1 0x7f948a96e680 in __libc_start_main /var/tmp/portage/sys-libs/glibc-2.23-r4/work/glibc-2.23/csu/../csu/libc-start.c:289
    #2 0x419b18 in _start (/usr/bin/amrenc+0x419b18)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: FPE /tmp/amrenc/amrenc.c:155:33 in main
==24102==ABORTING

Testcase attached
testcase.zip