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# FFmpeg cheat sheet
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A list of useful commands for the ffmpeg command line tool.
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Download FFmpeg: <https://www.ffmpeg.org/download.html>
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Full documentation: <https://www.ffmpeg.org/ffmpeg.html>
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## Basic conversion
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```bash
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ffmpeg -i in.mp4 out.avi
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```
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### Remux an MKV file into MP4
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```bash
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ffmpeg -i in.mkv -c:v copy -c:a copy out.mp4
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```
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### High-quality encoding
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Use the `crf` (Constant Rate Factor) parameter to control the output quality.
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The lower crf, the higher the quality (range: 0-51). The default value is 23,
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and visually lossless compression corresponds to `-crf 18`. Use the `preset`
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parameter to control the speed of the compression process.
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Additional info: <https://trac.ffmpeg.org/wiki/Encode/H.264>
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```bash
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ffmpeg -i in.mp4 -preset slower -crf 18 out.mp4
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```
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## Trimming
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Without re-encoding:
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```bash
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ffmpeg -ss [start] -i in.mp4 -t [duration] -c copy out.mp4
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```
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- [`-ss`](http://ffmpeg.org/ffmpeg-all.html#Main-options) specifies
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the start time, e.g. `00:01:23.000` or `83` (in seconds)
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- [`-t`](http://ffmpeg.org/ffmpeg-all.html#Main-options) specifies the duration
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of the clip (same format).
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- Recent `ffmpeg` also has a flag to supply the end time with `-to`.
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- [`-c`](http://ffmpeg.org/ffmpeg-all.html#Main-options) copy copies the first
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video, audio, and subtitle bitstream from the input to the output file without
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re-encoding them. This won't harm the quality and make the command run within seconds.
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With re-encoding:
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If you leave out the `-c copy` option, `ffmpeg` will automatically re-encode
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the output video and audio according to the format you chose. For high quality
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video and audio, read the [x264 Encoding Guide](https://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide)
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and the [AAC Encoding Guide](http://ffmpeg.org/trac/ffmpeg/wiki/AACEncodingGuide)
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, respectively.
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For example:
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```bash
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ffmpeg -ss [start] -i in.mp4 -t [duration] -c:v libx264 -c:a aac -strict
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experimental -b:a 128k out.mp4
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```
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## Mux video and audio from another video
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To copy the video from in0.mp4 and audio from in1.mp4:
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```bash
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ffmpeg -i in0.mp4 -i in1.mp4 -c copy -map 0:0 -map 1:1 -shortest out.mp4
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```
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- With [-c copy](http://ffmpeg.org/ffmpeg.html#Stream-copy) the streams will be
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`stream copied`, not re-encoded, so there will be no quality loss. If you want
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to re-encode, see [FFmpeg Wiki: H.264 Encoding Guide](https://trac.ffmpeg.org/wiki/Encode/H.264).
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- The `-shortest` option will cause the output duration to match the duration
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of the shortest input stream.
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- See the
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[`-map` option documentation](http://ffmpeg.org/ffmpeg.html#Advanced-options)
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for more info.
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## Concat demuxer
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First, make a text file.
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```bash
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file 'in1.mp4'
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file 'in2.mp4'
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file 'in3.mp4'
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file 'in4.mp4'
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```
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Then, run `ffmpeg`:
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```bash
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ffmpeg -f concat -i list.txt -c copy out.mp4
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```
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## Delay audio/video
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Delay video by 3.84 seconds:
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```bash
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ffmpeg -i in.mp4 -itsoffset 3.84 -i in.mp4 -map 1:v -map 0:a -vcodec copy
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-acodec copy out.mp4
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```
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Delay audio by 3.84 seconds:
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```bash
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ffmpeg -i in.mp4 -itsoffset 3.84 -i in.mp4 -map 0:v -map 1:a -vcodec copy
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-acodec copy out.mp4
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```
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## Burn subtitles
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Use the [libass](http://ffmpeg.org/ffmpeg.html#ass) library (make sure your
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ffmpeg install has the library in the configuration `--enable-libass`).
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First convert the subtitles to .ass format:
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```bash
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ffmpeg -i sub.srt sub.ass
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```
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Then add them using a video filter:
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```bash
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ffmpeg -i in.mp4 -vf ass=sub.ass out.mp4
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```
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## Extract the frames from a video
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To extract all frames from between 1 and 5 seconds, and also between 11 and 15 seconds:
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```bash
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ffmpeg -i in.mp4 -vf select='between(t,1,5)+between(t,11,15)' -vsync 0 out%d.png
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```
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To extract one frame per second only:
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```bash
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ffmpeg -i in.mp4 -fps=1 -vsync 0 out%d.png
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```
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## Rotate a video
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Rotate 90 clockwise:
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```bash
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ffmpeg -i in.mov -vf "transpose=1" out.mov
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```
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For the transpose parameter you can pass:
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```bash
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0 = 90CounterCLockwise and Vertical Flip (default)
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1 = 90Clockwise
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2 = 90CounterClockwise
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3 = 90Clockwise and Vertical Flip
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```
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Use `-vf "transpose=2,transpose=2"` for 180 degrees.
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## Download "Transport Stream" video streams
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1. Loate the playlist file, e.g. using Chrome > F12 > Network > Filter: m3u8
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2. Download and concatenate the video fragments:
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```bash
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ffmpeg -i "path_to_playlist.m3u8" -c copy -bsf:a aac_adtstoasc out.mp4
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```
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If you get a "Protocol 'https not on whitelist 'file,crypto'!" error
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, add the `protocol_whitelist` option:
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```bash
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ffmpeg -protocol_whitelist "file,http,https,tcp,tls" -i "path_to_playlist.m3u8"
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-c copy -bsf:a aac_adtstoasc out.mp4
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```
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## Mute some of the audio
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To replace the first 90 seconds of audio with silence:
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```bash
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ffmpeg -i in.mp4 -vcodec copy -af "volume=enable='lte(t,90)':volume=0" out.mp4
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```
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To replace all audio between 1'20" and 1'30" with silence:
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```bash
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ffmpeg -i in.mp4 -vcodec copy -af "volume=enable='between(t,80,90)':volume=0" out.mp4
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```
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## Deinterlace
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Deinterlacing using "yet another deinterlacing filter".
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```bash
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ffmpeg -i in.mp4 -vf yadif out.mp4
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```
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## Create a video slideshow from images
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Parameters: `-r` marks the image framerate (inverse time of each image);
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`-vf fps=25` marks the true framerate of the output.
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```bash
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ffmpeg -r 1/5 -i img%03d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p out.mp4
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```
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## Extract images from a video
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- Extract all frames: `ffmpeg -i input.mp4 thumb%04d.jpg -hide_banner`
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- Extract a frame each second: `ffmpeg -i input.mp4 -vf fps=1 thumb%04d.jpg -hide_banner`
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- Extract only one frame: `ffmpeg -i input.mp4 -ss 00:00:10.000 -vframes 1 thumb.jpg`
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## Metadata: Change the title
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```bash
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ffmpeg -i in.mp4 -map_metadata -1 -metadata title="My Title" -c:v copy -c:a
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copy out.mp4
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```
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