#367 Crash in fast_logmath_add

[Tom Meyer]

On some Android devices (Samsung S4 & Samsung Gear at least), values with d > 256 are being looked up in the last line of fast_logmath_add, in pocketsphinx/src/libpocketsphinx/tied_mgau_common.h:
return r - (((uint8 *)t->table)[d]);
This only crashes on some devices, but the documentation for this function says it shouldn't happen:
* We can do some extra-fast log addition since we know that
* mixw+ascr is always less than 256 and hence x-y is also always less
* than 256. This relies on some cooperation from logmath_t which
* will never produce a logmath table smaller than 256 entries.

I don't understand the code fully, so have not found a fix for the root cause, but in the meantime have patched it by clipping d to the table size:
if (d >= t->table_size) {
d = t->table_size-1;
}

[Nickolay V. Shmyrev]

Hi

Thanks for the repot

WHat version are you talking about, what CPU revision? Did you try the latest demo?

Could you provide corresponding raw recordings?

[Nickolay V. Shmyrev]

Hi. I found a possible cause of this behavior finally. You probably do not remember but did you use PTM model?

[Nickolay V. Shmyrev]

Should be fixed now.