FFmpeg Cheat Sheet

2 Jul 2021, 9:58 p.m.

23 Feb 2022, 3:54 p.m.

09:32 minutes

A handy cheat sheet of commands for the text line utility `ffmpeg`

Installing FFMpeg

apt-get install ffmpeg

Converting Audio into Different Formats / Sample Rates

Minimal example: transcode from MP3 to WMA:

ffmpeg -i input.mp3 output.wma

You can get the list of supported formats with:

ffmpeg -formats

You can get the list of installed codecs with:

ffmpeg -codecs

Convert WAV to MP3, mix down to mono (use one audio channel), set bit rate to 64 kbps and sample rate to 22050 Hz:

ffmpeg -i input.wav -ac 1 -ab 64000 -ar 22050 output.mp3

Convert any MP3 file to WAV 16khz mono 16bit:

ffmpeg -i 111.mp3 -acodec pcm_s16le -ac 1 -ar 16000 out.wav

Convert any MP3 file to WAV 20khz mono 16bit for ADDAC WAV Player:

ffmpeg -i 111.mp3 -acodec pcm_s16le -ac 1 -ar 22050 out.wav

cd into dir for the batch process:

for i in *.mp3; do ffmpeg -i "$i" -acodec pcm_s16le -ac 1 -ar 22050 "${i%.mp3}-encoded.wav"; done

Picking the 30 seconds fragment at an offset of 1 minute

ffmpeg -i input.mp3 -ss 60 -t 30 output.wav

In HH:MM:SS format

ffmpeg -i input.mp3 -ss 0:01:00 -t 0:00:30 output.wav

Split an audio stream at a specified segment rate (e.g. 3 seconds)

ffmpeg -i somefile.mp3 -f segment -segment_time 3 -c copy out%03d.mp3

Extract Audio

-vn signals no video. -acodec copy says to use the same audio stream that’s already in there.

ffmpeg -i input-video.avi -vn -acodec copy output-audio.aac

The -i option is the input file/path. The -f specifies the format (in this case mp3 and the -ab 192000 tells FFmpeg that we want the output to be encoded at 192Kbps, and as we learnt the last example -vn means we do not want video.

ffmpeg -i video.mp4 -f mp3 -ab 192000 -vn music.mp3

Replace Audio on a Video without re-encoding.

Preferred method

ffmpeg -i INPUT.mp4 -i AUDIO.wav -shortest -c:v copy -c:a aac -b:a 256k OUTPUT.mp4

Strip audio stream away from the video.

ffmpeg -i INPUT.mp4 -codec copy -an OUTPUT.mp4

Combine the two streams (new audio with originally existing video).

ffmpeg -i 36.MOV -i 36.wav -map 0:v -map 1:a -c copy -y 36-encoded.mov

Or add an offset to audio.

ffmpeg -i 36.MOV -itsoffset -0.25 -i 36.wav -map 0:v -map 1:a -c copy -y 36-encoded.mov

We can leave the audio format detection up to FFmpeg?

To convert one file:

 ffmpeg -i videofile.mp4 -vn -acodec libvorbis audiofile.ogg

To convert many files:

 for vid in *.mp4; do ffmpeg -i "$vid" -vn -acodec libvorbis "${vid%.mp4}.ogg"; done

You can, of course, select any FFmpeg parameters for audio encoding that you like, set things like bitrate, etc.

Use -acodec libmp3lame and change the extension from .ogg to .mp3 for mp3 encoding.

If you want to extract the audio, you can “copy” the audio track to a file using -acodec copy. Of course, the main difference is that transcoding is slow and CPU-intensive, while copying is speedy as you’re just moving bytes from one file to another. Here’s how to copy just the audio track (assuming it’s in mp3 format):

 ffmpeg -i videofile.mp4 -vn -acodec copy audiofile.mp3

Note that in this case, the audio file format has to be consistent with what the container has (i.e. if the audio is AAC format, you have to say audiofile.aac). You can use the ffprobe command to see which formats you have; this may provide some information:

 for file in *; do ffprobe $file 2>&1 |grep Audio; done

A possible way to automatically parse the audio codec and name the audio file accordingly would be

 for file in *mp4 *avi; do ffmpeg -i "$file" -vn -acodec copy "$file".```ffprobe "$file" 2>&1 |sed -rn 's/.*Audio: (...), .*/\1/p'```; done

Note that this command uses sed to parse output from ffprobe for each file. It assumes a 3-letter audio codec such as mp3, ogg or aac for example and will break if given anything different.

Encoding multiple files

You can use a Bash “for loop” to encode all files in a directory:

mkdir newfiles
for f in *.m4a; do ffmpeg -i "$f" -codec:v copy -codec:a libmp3lame -q:a 2 newfiles/"${f%.m4a}.mp3"; done

m4a to mp3 conversion with FFmpeg and lame

ffmpeg -i input.m4a -acodec libmp3lame -ab 128k output.mp3

A batch file version of the same command would be:

for f in *.m4a; do ffmpeg -i "$f" -acodec libmp3lame -ab 256k "${f%.m4a}.mp3"; done

Extract Single Image from a Video at Specified Frame

vf [ss][filename][outputFileName]

where vf is a custom bash script as follows:

ffmpeg -ss $1 -i $2 -qmin 1 -q:v 1 -qscale:v 2 -frames:v 1 -huffman optimal $3.jpg

ss offset = frame number divided by FPS of video = the decimal (in milliseconds) ffmpeg needs i.e. 130.5

Merge Multiple Videos

Concatenate multiple files.

cat myvideos.txt
file '/path/to/file1'
file '/path/to/file2'
file '/path/to/file3'

$ ffmpeg -f concat -safe 0 -i myvideos.txt -c copy output.mp4

Split a Video into Images

ffmpeg -i video.flv image%d.jpg

Convert Images into a Video

ffmpeg -f image2 -i image%d.jpg imagestovideo.mp4

ffmpeg -i image-%03d.png -c:v libx264 -pix_fmt yuv420p test.mp4

ffmpeg -r 1/5 -i image-%03d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p test.mp4

Convert Single Image into a Video

ffmpeg -loop 1 -i image.png -c:v libx264 -t 60 -pix_fmt yuv420p -vf scale=1920:1080 out.mp4

Convert non-sequentially named Images in a directory

ffmpeg -framerate 30 -pattern_type glob -i '*.jpeg' -c:v libx264 -pix_fmt yuv420p gan-1.mov

Convert image sequence of many different sizes and conform to specific frame size

ffmpeg -i image-%04d.jpg -c:v libx264 -pix_fmt yuv420p -vf "scale=max(1280\,a*720):max(1280\,720/a),crop=1280:720" test.mp4

Guarantee aspect ratio from the image sequence

ffmpeg -i image-%04d.jpg -c:v libx264 -pix_fmt yuv420p -vf "scale=720:-2" test.mp4

Evaluate which ratio to apply for scaling, then scale with the requisite amount of padding

ffmpeg -i image-%04d.jpg -c:v libx264 -pix_fmt yuv420p -vf "scale=iw*min(1280/iw\,720/ih):ih*min(1280/iw\,720/ih), pad=1280:720:(1280-iw*min(1280/iw\,720/ih))/2:(720-ih*min(1280/iw\,720/ih))/2" test.mp4

1920 version

ffmpeg -i image-%04d.jpg -c:v libx264 -pix_fmt yuv420p -vf "scale=iw*min(1920/iw\,1080/ih):ih*min(1920/iw\,1080/ih), pad=1920:1080:(1920-iw*min(1920/iw\,1080/ih))/2:(1080-ih*min(1920/iw\,1080/ih))/2" test.mp4

Convert .mov (JPEG-A or other codec) to H264 .mp4

ffmpeg -i input.mov -vcodec libx264 -pix_fmt yuv420p output.mp4

Simple FLAC convert

ffmpeg -i audio.xxx -c:a flac audio.flac

Mix Stereo to Mono

You can modify a video file directly without having to re-encode the video stream. However, the audio stream will need to encoded again.

If you want to use the right channel, write 0.1.1 instead of 0.1.0.

Left channel to mono:

ffmpeg -i video.mp4 -map_channel 0.1.0 -c:v copy mono.mp4

Left channel to stereo:

ffmpeg -i video.mp4 -map_channel 0.1.0 -map_channel 0.1.0 -c:v copy stereo.mp4

Trim End of a File (mp3)

This command will slice up to 30 seconds without transcoding:

ffmpeg -t 30 -i inputfile.mp3 -acodec copy outputfile.mp3

To Encode or Re-encode?

Do you need to cut video with re-encoding or without re-encoding mode? You can try the following command. Synopsis: ffmpeg -i [input_file] -ss [start_seconds] -t [duration_seconds] [output_file]

use FFmpeg cut mp4 video without re-encoding

Example:

ffmpeg -i source.mp4 -ss 00:00:05 -t 00:00:10 -c copy cut_video.mp4

use FFmpeg cut mp4 video with re-encoding

If you want to cut off section from the beginning, drop -t 00:00:10 from the command

ffmpeg -i source.mp4 -ss 00:00:05 -t 00:00:10 -async 1 -strict -2 cut_video.mp4

reduce filesize