general notes on ffmpeg

loops

ffmpeg consumes stdin and acts weird if you loop for example over a list of files provided by stdin.

solution:

while read -r file; do
    cat /dev/null | ffmpeg -i "${file}" "${file}.new"
done <./toEncode.lst

Amazone offers the files in default as m4a files

$ ffmpeg -i Weihnachtsklingel-6G8_sdQ26MY.m4a -vn -ab 128k -ar 44100 Weihnachtsklingel.mp3

Converts all mp3 files to flac

$ while read line ; do yes | ffmpeg -i "$line" "$(echo "$line" | sed -e 's/mp3/flac/g')" -vsync 2 ; done<<<$(find ./ -name "*mp3")

Converts $file into avi thats working on bones Kid Car TVs

$ ffmpeg -i "${file}" -vf scale=720:-1 -b:v 1.2M -vcodec mpeg4 -acodec mp3 "${destination:-.}/${file/%${file##*\.}/avi}"

$ ffmpeg -i inputfile -vf vflip -c:a copy outputfile

$ ffmpeg -i inputfile -vf hflip -c:a copy outputfile

$ ffmpeg -i inputfile -vf transpose=1 -c:a copy outputfile

$ ffmpeg -i inputfile -vf transpose=2 -c:a copy outputfile