ffmpeg \
    -i "${1}" \
    -vcodec copy \
    -acodec ac3 \
    -filter_complex "
        [0:a]pan=5.1|FL=1*FL|FR=1*FR|FC=0.7071*FL+0.7071*FR|LFE=0.5*FL+0.5*FR|BL=-0.8718*FL+0.4898*FR|BR=0.4898*FR+-0.8718*FL[UPMIXED],
        [UPMIXED]channelsplit=channel_layout=5.1[FL][FR][CTR][LFE][SL][SR],
        [LFE]lowpass=f=120[LFO],
        [CTR]highpass=f=120[CTO],
        [SL]adelay=150[SURL],
        [SR]adelay=150[SURR],
        [FL][FR][CTO][LFO][SURL][SURR]join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-LFE|4.0-BL|5.0-BR[audio]
    " \
    -map 0:v \
    -map [audio] \
    "${2}"