FFMPEG

Basic conversion

ffmpeg -i in.mp4 out.avi

Remux(lossless) 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

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 start time e.g. 00:01:23.000 or 83seconds

• -t the duration of the clip (same format) also can use -to

• -c copy copy file without re-encoding and make the command within seconds

With re-encoding

ffmpeg -ss [start] -i in.mp4 -t [duration] -c:v libx264 -c:a aac -strict experimental -b:a 128 out.mp4

Leave out -c copy option, ffmpeg will automatically re-encode the output video and audio according to the format you choose

Mux video and audio from another video

ffmpeg -i in1.mp4 -i in2.mp4 -c copy -map 0:0 -map 1:1 -shortest out.mp4

• With-c copy the streams will be stream copied, not re-encoded, so there will be no quality loss

• The -shortest option will cause the output duration to match the duration of the shortest input stream

• See the -map option documentation for more info

Concat demuxer

First, make a text file

Then, run ffmepg

ffmpeg -f concat -i list.txt -c copy out.mp4

If you get unsafe file name 'in1.mp4' list.txt: Operation not permitted

Execute command ffmpeg -f concat -safe 0 -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 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 seconds 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:

e.g. use -vf "transpose=2,transpose=2 for 180 degrees.

Download "Transport Stream" video streams

• Locate the playlist file, e.g. using Chrome > F12 > Network > Filter: m3u8

• 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

e.g. m3u8 file to video ffmpeg -allowed_extensions ALL -protocol_whitelist "file,http,crypto,tcp" -i index.m3u8 -c copy out.mp4

ffmpeg -i https://xxx.com/index.m3u8 -c copy aaa.mp4

Mute some of the audio

To replace the first 90 seconds of audio with silence

ffmpeg -i in.mp4 -vcodec copy -af "volumn=enable='lte(t, 90)':volumn=0" out.mp4

To replace all audio between 1'20'' and 1'30'' with silence

ffmpeg -i in.mp4 -vcodec copy -af "volumn=enable='lte(t, 80, 90)':volumn=0" out.mp4

Deinterlace(can't understand what is)

ffmpeg -i in.mp4 -vf yadif out.mp4

Create a video slideshow from images

ffmpeg -r 1/5 -i img%03d.png -c:v libx264 -vf fps=25 -pix-fmt yuv420p out.mp4

Parameters: -r marks the image framerate(inverse time of each image); -vf fps=25 marks the true framerate of the output

Extract images from a video

• All frames: ffmpeg -i in.mp4 thumb%04d.jpg -hide_banner

• A frame per second: ffmpeg -i in.mp4 -vf fps=1 thumb%04d.jpg -hide_banner

• Only one frame: ffmpeg -i in.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