CLI Commands

Cut/Trim Video

-ss specifies the starting position and -t specifies the duration from the start position

-c:v copy -c:a copy commands copy the original audio and video without re-encoding.

ffmpeg -i $input_file.mp4 -ss 00:00:00 -t 00:00:35 -c:v copy -c:a copy $output_file.mp4

-to to specify an exact time to cut to from the starting position

ffmpeg -i $input_file.mp4 -ss 00:00:00 -to 00:00:30 -c:v copy -c:a copy $output_file.mp4

Concatenate Videos

Concatenate videos present in a folder. This task can be done in two steps

1. add name of all the .mp4 files in .txt file

for i in *; do echo file $i >> videos.txt; done

2. Concatenate all files

ffmpeg -f concat -i videos.txt -codec copy output.mp4

Compress Video

Push the compression level further by increasing the CRF value — add, say, 4 or 6, since a reasonable range for H.265 may be 24 to 30.

ffmpeg -i $input_file.mp4 -vcodec libx265 -crf 28 $output_file.mp4

GIF converter

following skip the first 10 seconds -ss 10 of the input and create a 5 second output -t 3

Change as per your need

ffmpeg -i $input_file.mp4 -vf "fps=5,scale=640:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 $output_file.gif

Resize GIFs

change scale for relatively resizing gifs

ffmpeg -i input.gif -vf "scale=iw*3/4:ih*3/4" $resized_output_file.gif

Watermark

adjust watermark position

center - overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2
top left - overlay=(main_w-overlay_w):0
bottom left - overlay=0:(main_h-overlay_h)
bottom right - overlay=(main_w-overlay_w):(main_h-overlay_h)

following command overlays watermark in right bottom

ffmpeg -i $input_file.mp4 -i /home/prashant/Downloads/icon.png -filter_complex "[1][0]scale2ref=oh*mdar:ih*0.1[logo][video];[video][logo]overlay=(main_w-overlay_w-20):(main_h-overlay_h-20)" $output_scaled.mp4

add oppacity in watermark
format=rgba,colorchannelmixer=aa=0.3

ffmpeg -i $input_file.mp4 -i watermark.png -filter_complex "[1]format=rgba,colorchannelmixer=aa=0.3[logo];[logo][0]scale2ref=oh*mdar:ih[logo][video];[video][logo]overlay=overlay=(main_w-overlay_w-20):(main_h-overlay_h-20)" $output_center_cover_transparent.mp4

Remove Audio From Video

You can remove audio by using the -an flag

ffmpeg -f lavfi -i anullsrc -i $input_file.mp4 -c:v copy -c:a aac -map 0:a -map 1:v -shortest $output_file.mp4

Add Audio to Video

ffmpeg -i $input_file.mp4 -i $input_file.mp3 -c copy -map 0:v:0 -map 1:a:0 $output_file.mp4