[Source](https://gist.github.com/steven2358/ba153c642fe2bb1e47485962df07c730)
---
## Basic conversion
````
ffmpeg -i in.mp4 out.avi
````
## See a List of Codecs
```bash
ffmpeg -codecs
```
### Remux an MKV file into MP4
````
ffmpeg -i in.mkv -c:v copy -c:a copy out.mp4
````
### High-quality encoding
Use the `crf` (Constant Rate Factor) parameter to control the output quality. The lower crf, the higher the quality (range: 0-51). The default value is 23, and visually lossless compression corresponds to `-crf 18`. Use the `preset` parameter to control the speed of the compression process. Additional info: https://trac.ffmpeg.org/wiki/Encode/H.264
````
ffmpeg -i in.mp4 -preset slower -crf 18 out.mp4
````
## Trimming
Without re-encoding:
````
ffmpeg -ss [start] -i in.mp4 -t [duration] -c copy out.mp4
````
- [`-ss`](http://ffmpeg.org/ffmpeg-all.html#Main-options) specifies the start time, e.g. `00:01:23.000` or `83` (in seconds)
- [`-t`](http://ffmpeg.org/ffmpeg-all.html#Main-options) specifies the duration of the clip (same format).
- Recent `ffmpeg` also has a flag to supply the end time with `-to`.
- [`-c`](http://ffmpeg.org/ffmpeg-all.html#Main-options) copy copies the first video, audio, and subtitle bitstream from the input to the output file without re-encoding them. This won't harm the quality and make the command run within seconds.
With re-encoding:
If you leave out the `-c copy` option, `ffmpeg` will automatically re-encode the output video and audio according to the format you chose. For high quality video and audio, read the [x264 Encoding Guide](https://ffmpeg.org/trac/ffmpeg/wiki/x264EncodingGuide) and the [AAC Encoding Guide](http://ffmpeg.org/trac/ffmpeg/wiki/AACEncodingGuide), respectively.
For example:
````
ffmpeg -ss [start] -i in.mp4 -t [duration] -c:v libx264 -c:a aac -strict experimental -b:a 128k out.mp4
````
## Mux video and audio from another video
To copy the video from in0.mp4 and audio from in1.mp4:
````
ffmpeg -i in0.mp4 -i in1.mp4 -c copy -map 0:0 -map 1:1 -shortest out.mp4
````
- With [-c copy](http://ffmpeg.org/ffmpeg.html#Stream-copy) the streams will be `stream copied`, not re-encoded, so there will be no quality loss. If you want to re-encode, see [FFmpeg Wiki: H.264 Encoding Guide](https://trac.ffmpeg.org/wiki/Encode/H.264).
- The `-shortest` option will cause the output duration to match the duration of the shortest input stream.
- See the [`-map` option documentation](http://ffmpeg.org/ffmpeg.html#Advanced-options) for more info.
## Concat demuxer
First, make a text file.
````
file 'in1.mp4'
file 'in2.mp4'
file 'in3.mp4'
file 'in4.mp4'
````
Then, run `ffmpeg`:
````
ffmpeg -f concat -i list.txt -c copy out.mp4
````
## Delay audio/video
Delay video by 3.84 seconds:
````
ffmpeg -i in.mp4 -itsoffset 3.84 -i in.mp4 -map 1:v -map 0:a -vcodec copy -acodec copy out.mp4
````
Delay audio by 3.84 seconds:
````
ffmpeg -i in.mp4 -itsoffset 3.84 -i in.mp4 -map 0:v -map 1:a -vcodec copy -acodec copy out.mp4
````
## Burn subtitles
Use the [libass](http://ffmpeg.org/ffmpeg.html#ass) library (make sure your ffmpeg install has the library in the configuration `--enable-libass`).
First convert the subtitles to .ass format:
````
ffmpeg -i sub.srt sub.ass
````
Then add them using a video filter:
````
ffmpeg -i in.mp4 -vf ass=sub.ass out.mp4
````
## Extract the frames from a video
To extract all frames from between 1 and 5 seconds, and also between 11 and 15 seconds:
````
ffmpeg -i in.mp4 -vf select='between(t,1,5)+between(t,11,15)' -vsync 0 out%d.png
````
To extract one frame per second only:
````
ffmpeg -i in.mp4 -fps=1 -vsync 0 out%d.png
````
## Rotate a video
Rotate 90 clockwise:
````
ffmpeg -i in.mov -vf "transpose=1" out.mov
````
For the transpose parameter you can pass:
````
0 = 90CounterCLockwise and Vertical Flip (default)
1 = 90Clockwise
2 = 90CounterClockwise
3 = 90Clockwise and Vertical Flip
````
Use `-vf "transpose=2,transpose=2"` for 180 degrees.
## Download "Transport Stream" video streams
1. Locate the playlist file, e.g. using Chrome > F12 > Network > Filter: m3u8
2. Download and concatenate the video fragments:
````
ffmpeg -i "path_to_playlist.m3u8" -c copy -bsf:a aac_adtstoasc out.mp4
````
If you get a "Protocol 'https not on whitelist 'file,crypto'!" error, add the `protocol_whitelist` option:
````
ffmpeg -protocol_whitelist "file,http,https,tcp,tls" -i "path_to_playlist.m3u8" -c copy -bsf:a aac_adtstoasc out.mp4
````
## Mute some of the audio
To replace the first 90 seconds of audio with silence:
````
ffmpeg -i in.mp4 -vcodec copy -af "volume=enable='lte(t,90)':volume=0" out.mp4
````
To replace all audio between 1'20" and 1'30" with silence:
````
ffmpeg -i in.mp4 -vcodec copy -af "volume=enable='between(t,80,90)':volume=0" out.mp4
````
## Deinterlace
Deinterlacing using "yet another deinterlacing filter".
````
ffmpeg -i in.mp4 -vf yadif out.mp4
````
## Create a video slideshow from images
Parameters: `-r` marks the image framerate (inverse time of each image); `-vf fps=25` marks the true framerate of the output.
````
ffmpeg -r 1/5 -i img%03d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p out.mp4
````
## Extract images from a video
- Extract all frames: `ffmpeg -i input.mp4 thumb%04d.jpg -hide_banner`
- Extract a frame each second: `ffmpeg -i input.mp4 -vf fps=1 thumb%04d.jpg -hide_banner`
- Extract only one frame: `ffmpeg -i input.mp4 -ss 00:00:10.000 -vframes 1 thumb.jpg`
## Metadata: Change the title
````
ffmpeg -i in.mp4 -map_metadata -1 -metadata title="My Title" -c:v copy -c:a copy out.mp4
````
## With `yt-dlp`, make a clip of a video
`-ss` is the start time, and `-s` is the duration. More info [here](https://old.reddit.com/r/youtubedl/wiki/howdoidownloadpartsofavideo).
```bash
# Using seconds
yt-dlp \
-f 18 \
--external-downloader ffmpeg \
--external-downloader-args "ffmpeg_i:-ss 00:04:56.00 -t 5" \
"https://www.youtube.com/watch?v=rSc9xYPMAQY"
# Using timestamp
yt-dlp \
-f 18 \
--external-downloader ffmpeg \
--external-downloader-args "ffmpeg_i:-ss 00:04:56.00 -to 00:05:23.00" \
"https://www.youtube.com/watch?v=rSc9xYPMAQY"
```
## Creating Time-Lapse Videos
```bash
# Reduce to a smaller size (1080p) since
# "MPEG-1 does not support resolutions above 4095x4095"
for image in *.JPG; do ffmpeg -i $image -vf scale=1920:-1 ${image%.JPG}.PNG; done
# Create a movie!
ffmpeg -f image2 -pattern_type glob -i "*.PNG" output.mpg
# A lossless movie!
ffmpeg -pattern_type glob -i "*.PNG" -c:v mjpeg -qscale:v 0 output.mov
```
## Convert FLAC to M4A
This is for macOS. You'll need FFMpeg with [this encoder](https://github.com/mstorsjo/fdk-aac). The 'regular' FFMPeg from HomeBrew will not work for [reasons](https://stackoverflow.com/a/55108365).
👉 Do _not_ install `fdk-aac-encoder` to fix this issue!
```bash
brew tap homebrew-ffmpeg/ffmpeg
# or 'upgrade'. The "--HEAD" will fetch the latest release.
# Might save you trouble with ImageMagick versions.
brew install homebrew-ffmpeg/ffmpeg/ffmpeg --with-fdk-aac --HEAD
# Convert!
find . -name '*.flac' -exec sh -c 'ffmpeg -i "$1" -c:a libfdk_aac -b:a 320k "${1%.flac}.m4a"' _ {} \;
```
### Problems
#### ImageMagick Version
Just install the latest ImageMagick and FFmpeg with `--HEAD`.
#### Could not find tag for codec h264 in stream #0 codec
FFmpeg is [trying to transcode any cover art](https://stackoverflow.com/a/52370948). To fix, just add a `-c:v copy` to the command above.
---
## References
- [Scaling with ffmpeg](https://trac.ffmpeg.org/wiki/Scaling%20(resizing)%20with%20ffmpeg)
- [Video from images](http://en.wikibooks.org/wiki/FFMPEG_An_Intermediate_Guide/image_sequence)
- [Making a lossless movie](http://stackoverflow.com/questions/4839303/convert-image-sequence-to-lossless-movie)