-stream_loop option

ffmpeg -stream_loop 3 -i input.mp4 -c copy output.mp4

• This can avoid re-encoding because it can use stream copy.
• 0 means no loop, -1 means infinite loop.
• This may not work with anything older than FFmpeg 4.0.

concat demuxer

The concat demuxer allows you to loop an input without needing to re-encode because it can use stream copy.

1. Make a text file. Contents of an example text file to repeat 4 times.

    file 'input.mp4'
    file 'input.mp4'
    file 'input.mp4'
    file 'input.mp4'
   

2. Then run ffmpeg:

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

If you want to add additional inputs make sure they all have the same attributes.

Automatically make list.txt in Linux/macOS

This example is the same as above but you don't have to manually make list.txt:

for i in {1..4}; do printf "file '%s'\n" input.mp4 >> list.txt; done
ffmpeg -f concat -i list.txt -c copy output.mp4

With most commonly-used modern shells, you can even avoid the creation of the list.txt file entirely. For example, with bash:

ffmpeg -f concat -i <(for i in {1..4}; do printf "file '%s'\n" input.mp4; done) -c copy output.mp4

Also see:

• FFmpeg concat demuxer documentation
• FFmpeg Wiki: Concatenate

loop filter

Example using the loop filter to loop 4 times, each loop is 75 frames, each loop skips the first 25 frames of the input:

ffmpeg -i input.mp4 -filter_complex "loop=loop=3:size=75:start=25" output.mp4

• Or use the shorthand: loop=3:75:25
• Filtering requires re-encoding.
• This filter places all frames into memory.
• Using loop=3 will loop 4 times.
• To loop infinitely use -1.
• You must list the number of frames to loop (shown as 75 in the example above). Max value is 32767.
• Also see ffmpeg -h filter=loop.

movie filter

The movie and amovie filters have a loop option:

ffmpeg -f lavfi -i "movie=filename=input.mp4:loop=4,setpts=N/FRAME_RATE/TB" -f lavfi -i "amovie=filename=input.mp4:loop=4,asetpts=N/SR/TB" output.mp4

• Filtering requires re-encoding.
• 1 means no loop, 0 means infinite loop.

-loop option

The -loop option is specific to the image file demuxer and gif muxer, so it can't be used for typical video files. But it can be used to infinitely loop a single image or a series of images.

single image

This example will loop a single image over and over but the -t 30 will limit the output duration to 30 seconds:

ffmpeg -loop 1 -i input.png -t 30 -vf format=yuv420p output.mp4

-vf format=yuv420p is for compatibility reasons.

series of images

ffmpeg -loop 1 -i %03d.jpg -t 30 -vf format=yuv420p output.mp4

GIF output

Or to loop a GIF:

ffmpeg -i input -loop 3 output.gif

For GIF output also see How do I convert a video to GIF using ffmpeg, with reasonable quality?

Maybe this will help - enter it all on a single line and it will stream a single image (called test.jpg) repeatedly. See: https://stackoverflow.com/a/71885708/18795194 for my post and an explanation of the parameters.

ffmpeg 
-loop 1 
-fflags +genpts 
-framerate 1/30 
-i test.jpg 
-c:v libx264 
-vf fps=25 
-pix_fmt yuvj420p 
-crf 30 
-f fifo -attempt_recovery 1 -recovery_wait_time 1 
-f flv rtmp://localhost:5555/video/test

Use the tpad filter for this.

ffmpeg -framerate 30 -pattern_type sequence -i fr_f6a20_%04d.png -vf "tpad=start_duration=1:start_mode=clone:stop_duration=1:stop_mode=clone" -pix_fmt yuv420p out.mp4

Assuming you're working with the 50 frame sequence,

ffmpeg -framerate 24 -i %04d.png
 -filter_complex "[0]trim=end_frame=25,split=2[fo][re];[fo]loop=118:1:24,setpts=N/24/TB[fo];
                    [re]reverse,setpts=N/24/TB[re];[fo][re]concat=n=2:v=1:a=0"
 -c:v libx264 -crf 25 -pix_fmt yuv420p   out.mp4

[0]trim=end_frame=25 --> keep the first 25 frames. Frames are numbered starting with 0.

split=2[fo][re] --> have two copies of this trimmed segment

[fo]loop=118:1:24 --> Loop the single frame 1 at the end 24 118 times. So there's 119 instances of the last frame.

setpts=N/24/TB[fo] --> long story short, ffmpeg is meant to work with timed media, so this filter is to make sure the segment now with the loop has smooth, continuous timestamps. 24 is the framerate of the input.

[re]reverse --> reverse the 2nd copy of the trimmed segment.

setpts=N/24/TB[re] --> same as above.

[fo][re]concat=n=2:v=1:a=0 --> join the two segments - the looped one, and the reversed one. Since the 25th frame is the first frame of the reversed sequence, there's 120 instances of the 25th frame.

An old question, but you can use a loop-trim combo:

ffmpeg -i video.mp4 -i audio.mp3 \
  -filter_complex "[0:v]loop=loop=-1:size=1,trim=end=1[v0];\
                   [v0][0:v]concat" \
  -c:a copy -map 1:a out.mkv")

Specifying size=1 for the loop filter, only the first frame is selected. Since loop only specify its looping duration in terms of the number of loops, use the subsequent trim filter to stop the stream at the desired padding duration.

You can just use stream_loop switch for input to loop that without any calculations:

ffmpeg -stream_loop 4 -i input.mp4 output.mp4

See main options

-stream_loop number (input) Set number of times input stream shall be looped. Loop 0 means no loop, loop -1 means infinite loop.

To also answer whether there's any const/var to use in loop filter - as of now, it doesn't look like that's possible. Documentation doesn't list anything, there isn't also anything in the code, size is defined as integer higher than or equal to 0.

The quickest way is via the stream_loop option,

ffmpeg -stream_loop 3 -i D:\21-03-2018\15271618235b06a3df9d5cb.mp4 -c copy D:\21-03-2018\output.mp4

Use

ffmpeg -i ~/Desktop/file.mpg -vsync 0 ~/Desktop/file.mp4

This skips duplication.

-vsync passthrough is synonymous with -vsync 0.

Create a text file list containing all your image file names, but duplicating the first and last 100 times:

1.jpeg
1.jpeg
1.jpeg
......
2.jpeg
3.jpeg
....

Then:

cat $(cat list.txt) | ffmpeg -y -framerate 25/1 -i - -f image2pipe -c:v libx264 -pix_fmt yuv420p out.mp4