How to add offset or delay to audio file with ffmpeg?

Question

I need offset (some silence) in the start of file, so I tried:

./ffmpeg -itsoffset 100 -i 3.mp3 offset_test.mp3

But it doesn't work.

How to add offset to audio file with ffmpeg?

Impeachable

Try concatenating silence instead. – Aksum

Doesn't offset work with audio at all? – Impeachable

itsoffset is for adjusting timestamps... that's not at all what you actually want to do. You want to add some silence to the start of your file, and therefore you need to concatenate silence with your audio. – Aksum

see also Add 1 second of silence to audio through FFmpeg – Psychopath

Answer 1

For formats without timestamps, you'll need to add silence, as @Brad mentioned.

ffmpeg -i 3.mp3 -af adelay=100000|100000 delayed.mp3

The adelay takes delay in milliseconds per channel, separated by |.

Fanfaron

Thanks, adelay is exactly what I need. – Impeachable

It works in command: ffmpeg -vn -i 1.mp3 -i 2.mp3 -filter_complex "[a]adelay=2000|2000[a];[a][b]amix=inputs=2:dropout_transition=0" -q:a 1 -acodec libmp3lame -y amix_test.mp3, but when I try ffmpeg -i 3.mp3 -af adelay=100000|100000 delayed.mp3 it says At least one output file must be specified maybe you can say how specify output? – Impeachable

If you're on windows, you'll need to enclose the adelay string in quotes. – Fanfaron

What if, instead, of delay, we want to remove time (bring it forward) from the audio? – Atworth

You would use the atrim filter. Or simply use ffmpeg -ss X -i 3.mp3 -c copy trimmed.mp3 where X is the duration in seconds of leading content to be trimmed. – Fanfaron

Hi Gyan, thanks for your reply. I was hoping that if there is some single filter that could handle the positive delay (add delay to audio) or negative delay (remove time from the audio). Like the -itsoffset filter. Do you know if -itsoffset could be used only for audio files? wjwoodrow.wordpress.com/2013/02/04/… – Atworth

itsoffset is relevant only when combining with other audio or video streams - not for solitary audio-only files like a .mp3 – Fanfaron

It extends audio to 10 times of original length. Here's my command ffmpeg -i output-audio.aac -af "adelay=58000|58000" output2-audio.aac – Atomize

@Atworth I had to mix a video file without audio, with another audio file. The audio file was a bit in advance, trimming the video file by 0.5 second did the trick ! $ ffmpeg -ss 0.5 -i silent_video.mp4 -i audio.flac -c:v copy -c:a aac -strict experimental synchronized_video_with_sound.mp4 – Triceratops

Answer 2

The easiest way I found so far for ffmpeg ver > 4.2:

ffmpeg -i audio_in.wav -af areverse,apad=pad_dur=1s,areverse audio_out.wav

This will add an offset of 1 second to the audio.

Seaway

Answer 3

The correct way for -itsoffset should be:

ffmpeg -i audiofile.mp3 -itsoffset 100 offsetted.mp3

however, I'm not sure if -itsoffset will work.

Midland

Not true! itsoffset is an input option and as such need to precede the input file. See ffmpeg: "As a general rule, options are applied to the next specified file. Therefore, order is important, and you can have the same option on the command line multiple times. Each occurrence is then applied to the next input or output file." – Orson