My Command Line Audio Video Workflows with FFmpeg

FFmpeg is a free and open-source software project consisting of a large suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the FFmpeg program itself, designed for command-line-based processing of video and audio files.

Converting videos and audio has never been this easy. I’m able to do a lot of excellent tricks with this command-line tool. Actually, that’s a good enough introduction — let me share the real deal.

Gif to Video with FFmpeg#

# Gif to video.
# https://web.dev/replace-gifs-with-videos/
function gif2vid() {
	if [[ "-h" == "$1" ]]; then
		echo "-"
		echo "${wb}${bf}— Help! —${r}"
		echo "${wb}${bf}USAGE: rgif2vid some.gif nameOfVideos${r}"
		echo "-"
		return 1
	else
		ffmpeg -i "$1" "$2".mp4
		ffmpeg -i "$1" -c vp9 -b:v 0 -crf 41 "$2".webm
	fi
}

Cut 1 Minute from the start of a video with FFmpeg#

# Video cutting.
function cut1min() {
	for i in *.mp4;
	do name=`echo "$i" | cut -d'.' -f1`
	echo "$name"
	ffmpeg -ss 00:00:00.000 -i "$i" -t 60 -c:v libx264 -c:a copy "${name}-1min.mp4"
	done
}

Trim X seconds from the start of a video (FFmpeg-bar)#

# vidtrim <vid file name> <seconds to trim from start>
# vidtrim vid.mp4 5
function vidtrim() {
	ffmpeg-bar -i "$1" -ss "$2" -vcodec copy -acodec copy trimmed-"$1"
}

Join multiple videos with FFmpeg — without re-encoding#

# vidjoin <intro vid file name> <actual vid file name>
# vidjoin intro.mp4 input.mp4
function vidjoin() {
	 echo file "$1" >> vidjoin.txt
	 echo file "$2" >> vidjoin.txt
	 ffmpeg-bar -f concat -i vidjoin.txt -c copy output.mp4
	 rm vidjoin.txt
}

Extract audio stream from video without re-encoding#

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

• -vn is no video.
• -acodec copy use the same audio stream that’s already in there.

Rotate a video with FFmpeg#

# Rotate 90 clockwise:
ffmpeg -i in.mov -vf "transpose=1" out.mov

For the transpose parameter you can pass:
0 = 90 Counter Clockwise and Vertical Flip (default)
1 = 90 Clockwise
2 = 90 Counter Clockwise
3 = 90 Clockwise and Vertical Flip

Use -vf "transpose=2,transpose=2" for 180 degrees.

Convert an entire directory to one video with FFmpeg#

For Linux and macOS this can be done in one line, using parameter expansion to change the filename extension of the output file:

for i in *.avi; do ffmpeg -i "$i" "${i%.*}.mp4"; done

An alternate method would be like this:

for i in *.avi;
  do name=`echo "$i" | cut -d'.' -f1`
  echo "$name"
  ffmpeg -i "$i" "${name}.mov"
done

To convert with subdirectories use:

find . -exec ffmpeg -i {} {}.mp3 \;

Get FFmpeg information in a friendly way#

You can use -progress - to print-friendly info formatted by key=value.

ffmpeg -i vid.mp4 -progress - -y out.mp4

speed=3.15x
frame=458
fps=45.8
stream_0_0_q=39.0
bitrate=2337.0kbits/s
total_size=1231258682
out_time_ms=12323423
out_time=00:00:58.44534
dup_frames=0
drop_frames=0

Capture High-quality Images from a video with FFmpeg#

You can use -qscale:v (or the alias -q:v) to control image quality from a video as an output option.

• The normal range for JPEG is 2-31 with 31 being the worst quality.
• Linear scale with double qscale being roughly half the bitrate.
• I recommend trying values of 2-5.
• You can use a value of 1 but you must add the -qmin 1 output option (because the default is -qmin 2).

ffmpeg -i input.mp4 -qscale:v 2 output_%03d.jpg

ffmpeg -ss 60 -i input.mp4 -qscale:v 4 -frames:v 1 output.jpg

ffmpeg -i infile.mp4 -i infile.srt -c copy -c:s mov_text outfile.mp4

ffmpeg -i mymovie.mp4 -vf subtitles=subtitles.srt mysubtitledmovie.mp4

ffmpeg -i subtitles.srt subtitles.ass

ffmpeg -i mymovie.mp4 -vf ass=subtitles.ass mysubtitledmovie.mp4

ffmpeg -i file.mp4 2>&1 | grep Duration | sed 's/Duration: \(.*\), start/\1/g'

I hope you enjoy some of these. I’ll take some more time out to explain all of these and add a couple more which are tied up in a bit extra complex workflow, un-needed for this post.

Use your code for good. Peace!