I send RTMP stream with G.711 audio to Trascoder AddOn. G.711 has 8000 Hz sample rate. Wowza crashes with message:

*** glibc detected *** java: double free or corruption (out): 0x00007fb63815c4f0 ***
======= Backtrace: =========
In log I've found that audio decoder was created with 16000 Hz sample rate:

INFO stream create - -
INFO stream publish camera_00306F84293F_code -
INFO server comment - JNI:TranscoderSession.audioDecoderCreate[_defaultVHost_:rtp-live/_definst_/camera_00306F84293F]: Create audio decoder: G711 MULAW: default
INFO transcoder decoder-audio-start camera_00306F84293F {codec:G711_MULAW, objectType:0, sampleRate:16000, channels:1}
Please, tell me where can I initialize audio decoder with 8000 Hz sampleRate?