ffmpeg command history

ffmpeg-i-have-used.md

Degrade HD movie

$ ffmpeg -i source.mp4 -vf fps=fps=15,scale=480:-1 -b:v 450k -b:a 50k out.mp4

Convert mp4 into gif and scale it with maintaining aspect ratio.

• -vf scale: https://ffmpeg.org/ffmpeg-filters.html#scale

$ ffmpeg -i in.mp4 -vf scale=1024:-1 out.gif

Convert mp4 into gif, set fps, and scale it to half size with maintaining aspect ratio.

• -vf scale: https://ffmpeg.org/ffmpeg-filters.html#scale
• -vf fps: https://ffmpeg.org/ffmpeg-filters.html#fps-1

$ ffmpeg -i in.mp4 -vf fps=fps=30,scale=w=iw/2:-1 out.gif

Convert mp4 into fMP4 hls.

• -hls_segment_type: https://ffmpeg.org/ffmpeg-formats.html#hls-2

ffmpeg -i ~/20200526_200518.mp4 -f hls -hls_segment_type fmp4 -hls_playlist_type vod -c:v copy stream.m3u8

Crop a video temporally and spatially (width=1300, height=1200, x=1700, y=3000, from 00:10 to 00:22).

• -vf crop: https://ffmpeg.org/ffmpeg-all.html#crop
• -ss, -t: https://ffmpeg.org/ffmpeg-all.html#Main-options

$ ffmpeg -i in.mp4 -vf "crop=1300:1200:1700:300" -ss 00:10 -t 00:12 out.mp4

Create LGTM gif

• -filter_complex drawtext="..." http://ffmpeg.org/ffmpeg-filters.html#drawtext-1

$ ffmpeg -i input.mp4 -filter_complex drawtext="fontfile=/System/Library/Fonts/Helvetica.ttc:fontsize=160:fontcolor=white:x=(w-text_w)/2:y=(h-text_h)/2:text='LGTM'" -t 00:00:03 output.gif

Make video 2x speed.

$ ffmpeg -i in.mp4 -vf setpts=PTS/2.0 -af atempo=2.0 out.mp4

Extract .wav file from .mp4 in 44.1kHz stereo.

$ ffmpeg -i in.mp4 -t 00:10:00 -ac 2 -ar 44100 out.wav

mp4 to ts

• from 00:01:00, duration 10s
• length of ts file is 0.666s

ffmpeg -i in.mp4 -g 10 -hls_time 0.666 -ss 00:01:00 -t 00:00:10 out.m3u8

Generate video from png

$ ffmpeg -framerate 5 -i 'one-image.png' -pix_fmt yuv420p movie.mp4

$ ffmpeg -framerate 5 -pattern_type glob -i 'image*.png' -pix_fmt yuv420p movie.mp4

• https://stackoverflow.com/questions/24961127/how-to-create-a-video-from-images-with-ffmpeg

Mute video

$ ffmpeg -i in.mp4 -an out.mp4

• https://qiita.com/UedaTakeyuki/items/dde975d350cf640d8af8
• https://ffmpeg.org/ffmpeg.html#Audio-Options

Audio

Merge 2 audio files

ffmpeg -i recorded.wav -i bgm.mp3 -filter_complex amerge -ac 2 -c:a libmp3lame -q:a 4 output.mp3

• https://stackoverflow.com/questions/14498539/how-to-overlay-two-audio-files-using-ffmpeg

Streaming

Publish rtmp stream from mp4 file

• https://trac.ffmpeg.org/wiki/StreamingGuide
• -stream_loop: https://ffmpeg.org/ffmpeg.html#Main-options
• -re: https://ffmpeg.org/ffmpeg.html#Advanced-options

ffmpeg -y -stream_loop -1 -re -i ~/20200526_200518.mp4 -f flv rtmp://192.168.11.7:1935/app/stream