How to Merge Multiple Videos

Need to join video clips? Here's the best methods for different situations.

Method 1: Same Format (Fastest)

Create list.txt:

file 'clip1.mp4'
file 'clip2.mp4'
file 'clip3.mp4'

Then run:

ffmpeg -f concat -safe 0 -i list.txt -c copy merged.mp4

• -safe 0: Allows relative paths
• -c copy: No re-encoding (instant)

Method 2: Different Formats

ffmpeg -i video1.mp4 -i video2.avi -filter_complex "[0:v][0:a][1:v][1:a]concat=n=2:v=1:a=1[outv][outa]" -map "[outv]" -map "[outa]" merged.mp4

This re-encodes for compatibility.

Method 3: Different Resolutions

First normalize resolution:

ffmpeg -i input.mp4 -vf "scale=1920:1080" -c:a copy scaled.mp4

Then merge using Method 1.

Auto-generate List

ls *.mp4 | sed "s/^/file '/" | sed "s/$/'/" > list.txt

Troubleshooting

No audio after merge? Use Method 2 which handles multiple audio tracks properly.

"Unsafe file name" error? Add -safe 0 or use absolute paths.

Quick Reference

# Same format
ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4

# Different formats
ffmpeg -i a.mp4 -i b.mp4 -filter_complex "[0:v][0:a][1:v][1:a]concat=n=2:v=1:a=1[v][a]" -map "[v]" -map "[a]" output.mp4

Merge videos effortlessly!