ffmpeg video compression / specifc file size

encode-mp4.txt

(38.5 MiB * 8192 [converts MiB to kBit]) / 260 seconds = ~1213 kBit/s total bitrate
1213 - 96 kBit/s (desired audio bitrate) = 1117 kBit/s video bitrate

38.5 * 8192.0 / (4 * 60 + 20) - 96 = 1117

ffmpeg -y -i input.mp4 -c:v libx264 -preset medium -movflags faststart -b:v 1117k -pass 1 -an -f mp4 /dev/null && \
ffmpeg -i input.mp4 -c:v libx264 -preset medium -movflags faststart -b:v 1117k -pass 2 -b:a 96k output.mp4

4320p, 2160p, 1080p, 1080i, 720p, 720i, 576p, 576i, 480p, 480i, 360p, 240p

20mb goal
19.5 * 8192.0 / (4 * 60 + 20) - 96 =

ffmpeg -ss 01:27:08.0 -i input.m4v -ss 00:01:00.0 -t 00:00:59 -preset veryslow -tune film -movflags +faststart video3.mp4

ffmpeg -ss 00:51:18.0 -i input.m4v -ss 00:01:00.0 -t 00:05:40 -map 0:v:0 -map 0:a:1 -preset veryslow -tune film -movflags +faststart video.mp4

ffmpeg -ss 00:41:18.0 -i input.m4v -ss 00:01:00.0 -t 00:05:40 -vf scale=-1:574 -preset veryslow -tune film -b:v 385k -b:a 64k -movflags +faststart video2.mp4

ffmpeg -ss 00:55:53.0 -i input.m4v -ss 00:01:00.0 -t 00:03:02 -map 0:v:0 -map 0:a:1 -vf scale=-1:574 -preset veryslow -tune film -b:v 750k -b:a 96k -movflags +faststart video3.mp4

5.1 to stereo
-ac 2

-map_chapters -1
-map_metadata -1

ffmpeg -ss 01:42:50.0 -i abc.mkv -ss 00:00:59.0 -t 00:04:00 -map 0:v:0 -map 0:a:2 -b:v 800k -tune film -preset veryslow -movflags +faststart -ac 2 -b:a 128k -map_metadata -1 -map_chapters -1 tmbu03en_4.mp4

find . -name '*.webm' -exec NAME={}; ffmpeg -i "${NAME/\.\//}" -preset veryslow -tune film -movflags +faststart -map_metadata -1 "${NAME/\.\//}.mp4"; pwd ";"

docker run -v $(pwd):$(pwd) -w $(pwd) jrottenberg/ffmpeg -i before.webm -tune animation -movflags +faststart -map_metadata -1 after.mp4