Private Joe Bauers, a decisively average American,
is selected as a guinea pig for a top-secret hibernation program
but is forgotten, awakening to a future so incredibly moronic
he's easily the most intelligent person alive.

this is a remux of 2 releases:
video: 720p:
Idiocracy (2006) 720p BluRay X264 [MoviesFD]
audio: german + english:
Idiocracy.2006.German.DL.WEB.x264.iNTERNAL-BiGiNT

# remux with audio delay = 1400ms
ffmpeg \
-itsoffset 1.4 -i "Idiocracy (2006) 720p BluRay X264 [MoviesFD]/Idiocracy.2006.720P.Bluray.X264.[Moviesfd].mkv" \
-i Idiocracy.2006.German.DL.WEB.x264.iNTERNAL-BiGiNT/Idiocracy.2006.German.DL.WEB.x264.iNTERNAL-BiGiNT.mkv \
-map 0:v:0 -map 1:a:0 -map 1:a:1 -map 1:s:1 -map 1:s:2 -map_metadata -1 \
-metadata:s:a:0 language=ger -metadata:s:a:1 language=eng -metadata:s:s:0 language=ger -metadata:s:s:1 language=eng \
-default_mode infer_no_subs -c copy temp.mkv

# audio: 5.1 -> stereo -> ac3
# 640 kb/s -> 160 kb/s
# 386MByte -> 97MByte
# https://superuser.com/a/1420109/951886
# more center -> voices are louder/clearer that with Dave_750's formula
# ac3 has the best compatibility with hardware players
ffmpeg -i temp.mkv -map 0:a:0 -c ac3 -b:a 160k -vol 425 -af "pan=stereo|FL=0.8*FC+0.6*FL+0.6*BL+0.6*SL+0.5*LFE|FR=0.8*FC+0.6*FR+0.6*BR+0.6*SR+0.5*LFE" -strict -2 ger.ac3
ffmpeg -i temp.mkv -map 0:a:1 -c ac3 -b:a 160k -vol 425 -af "pan=stereo|FL=0.8*FC+0.6*FL+0.6*BL+0.6*SL+0.5*LFE|FR=0.8*FC+0.6*FR+0.6*BR+0.6*SR+0.5*LFE" -strict -2 eng.ac3

# remux with stereo audio
ffmpeg -i temp.mkv -i ger.ac3 -i eng.ac3 \
-map 0:v:0 -map 1:a:0 -map 2:a:0 -map 0:s:0 -map 0:s:1 \
-map_metadata 0 -metadata:s:a:0 language=ger -metadata:s:a:1 language=eng \
-c copy -default_mode infer_no_subs out.mkv