ffmpeg -i input.mp4 -c copy output.mkv

ffmpeg -i input.avi -c:v copy -c:a copy output.mkv

ffmpeg -i video.mp4 -i audio1.aac -i audio2.aac \
  -map 0:v -map 1:a -map 2:a -c copy output.mkv

ffmpeg -i input.mp4 -c:v mpeg4 -vtag xvid -q:v 5 -c:a libmp3lame output.avi

ffmpeg -i input.avi -c:v libx264 -crf 23 -c:a aac output.mp4

ffmpeg -i input_high.mp4 -b:v 2M -maxrate 2M -bufsize 4M \
  -c:a aac -b:a 128k output_compressed.mp4

ffmpeg -i input.mp4 -c:v copy -c:a aac -b:a 96k output.mp4

for file in *.mkv; do
  ffmpeg -i "$file" -c:v libx264 -crf 23 -c:a aac "${file%.mkv}.mp4"
done

for file in *.{mp4,avi,mov}; do
  [ -f "$file" ] && ffmpeg -i "$file" -c:v libvpx-vp9 -crf 30 \
    -c:a libopus "${file%.*}.webm"
done

ls *.mkv | parallel ffmpeg -i {} -c:v libx264 -crf 23 -c:a aac {.}.mp4

ffmpeg -i input.mp3 -c:a flac output.flac

ffmpeg -i input.wav -c:a alac output.m4a

ffmpeg -i subtitles.srt subtitles.ass

ffmpeg -i input.mkv -map 0:s:0 output.srt

ffmpeg -i input.mp4 \
  -c:v libx264 -b:v 5M -s 1920x1080 output_1080p.mp4 \
  -c:v libx264 -b:v 2M -s 1280x720 output_720p.mp4 \
  -c:v libx264 -b:v 1M -s 854x480 output_480p.mp4

# Create file list
echo "file 'video1.mp4'" > list.txt
echo "file 'video2.mp4'" >> list.txt
echo "file 'video3.mp4'" >> list.txt

# Concatenate
ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4

ffmpeg -i video1.mp4 -i video2.mp4 -filter_complex \
  "[0:v][0:a][1:v][1:a]concat=n=2:v=1:a=1[v][a]" \
  -map "[v]" -map "[a]" output.mp4

ffprobe -v error -show_format -show_streams input.mp4

ffprobe -v error -select_streams v:0 -show_entries stream=codec_name \
  -of default=nw=1:nk=1 input.mp4