How to Create a Lead-Out in FFmpeg

While FFmpeg does not have a standalone filter explicitly named leadout, creating a lead-out—whether as a gradual fade to black, an audio fade to silence, or trailing padding at the end of a stream—is directly achieved using the fade, afade, tpad, and apad filters. This guide covers how to implement these filters to construct seamless lead-outs for both video and audio files.

Video Fade-Out Using fade

To create a visual lead-out that fades a video to black, use the fade video filter with the type=out parameter. You must specify the starting point and the duration of the fade.

ffmpeg -i input.mp4 -vf "fade=type=out:start_time=55:duration=5" -c:a copy output.mp4
  • type=out: Designates the filter as a fade-out (lead-out).
  • start_time=55: The timestamp in seconds where the fade begins.
  • duration=5: The length of the fade in seconds.
  • -c:a copy: Copies the audio stream without re-encoding.

Alternatively, you can define the lead-out by frame count using start_frame and nb_frames:

ffmpeg -i input.mp4 -vf "fade=t=out:s=1650:n=150" -c:a copy output.mp4

Audio Fade-Out Using afade

To fade audio to silence at the end of a track or video, use the afade filter.

ffmpeg -i input.mp3 -af "afade=type=out:start_time=55:duration=5" output.mp3
  • type=out: Applies an audio fade-out.
  • start_time=55: The timestamp in seconds when the audio volume begins to drop.
  • duration=5: The duration in seconds over which the audio reaches total silence.

Adding Black Screen Padding Using tpad

If you need a lead-out that extends the end of a video with extra black frames or holds the last frame, use the tpad (time pad) filter.

To append 3 seconds of black frames:

ffmpeg -i input.mp4 -vf "tpad=stop_mode=add:stop_duration=3:color=black" -c:a copy output.mp4

To hold the final frame for 3 seconds as a lead-out:

ffmpeg -i input.mp4 -vf "tpad=stop_mode=clone:stop_duration=3" -c:a copy output.mp4
  • stop_mode=add: Adds solid color frames to the end.
  • stop_mode=clone: Freezes and repeats the last video frame.
  • stop_duration=3: The length of the lead-out in seconds.

Adding Trailing Silence Using apad

To extend an audio stream with silent lead-out time, use the apad filter combined with -t to define the total duration:

ffmpeg -i input.wav -af "apad=pad_dur=4" output.wav
  • pad_dur=4: Appends 4 seconds of silence to the end of the audio track.

Complete Combined Lead-Out Example

To apply both a video fade to black and an audio fade to silence simultaneously, combine the filters:

ffmpeg -i input.mp4 -vf "fade=type=out:start_time=55:duration=5" -af "afade=type=out:start_time=55:duration=5" -c:v libx264 -c:a aac output.mp4

This ensures both the picture and sound smoothly conclude over the final 5 seconds of a 60-second clip.