ADM_faad::initFaad invokes memcpy:
memcpy(extraData,d,l);
when called from ADM_faad::resetAfterSeek, d=extraData, so it's asking memcpy to copy a buffer into itself, which may or may not work, depending on the implementation of memcpy.
valgrind complains (just loaded a file and hit play):
Source and destination overlap in memcpy(0x1fb7a960, 0x1fb7a960, 2)
at 0x4A0A1D0: memcpy@@GLIBC_2.14 (mc_replace_strmem.c:881)
by 0xFAE6EB6: ADM_faad::initFaad(WAVHeader*, unsigned int, unsigned char*) (in /usr/lib64/ADM_plugins6/audioDecoder/libADM_ad_faad.so)
by 0xFAE6FC3: ADM_faad::resetAfterSeek() (in /usr/lib64/ADM_plugins6/audioDecoder/libADM_ad_faad.so)
by 0x4561EC: ADM_edAudioTrackFromVideo::goToTime(unsigned long) (in /usr/bin/avidemux3_qt4)
by 0x440A93: AUDMAudioFilter_Bridge::AUDMAudioFilter_Bridge(ADM_edAudioTrack*, unsigned int, int) (in /usr/bin/avidemux3_qt4)