Skillsbench FFmpeg Video Editing

Cut, trim, concatenate, and split video files - basic video editing operations

install

source · Clone the upstream repo

git clone https://github.com/benchflow-ai/skillsbench

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/benchflow-ai/skillsbench "$T" && mkdir -p ~/.claude/skills && cp -r "$T/tasks/multilingual-video-dubbing/environment/skills/ffmpeg-video-editing" ~/.claude/skills/benchflow-ai-skillsbench-ffmpeg-video-editing && rm -rf "$T"

manifest: tasks/multilingual-video-dubbing/environment/skills/ffmpeg-video-editing/SKILL.md

source content

FFmpeg Video Editing Skill

Basic video editing operations: cutting, trimming, concatenating, and splitting videos.

When to Use

Cut segments from video
Trim video length
Concatenate multiple videos
Split video into parts
Extract specific time ranges

Cutting and Trimming

# Cut from 10s to 30s (using -ss and -to)
ffmpeg -ss 00:00:10 -to 00:00:30 -i input.mp4 -c copy output.mp4

# Cut from 10s for 20 seconds duration
ffmpeg -ss 00:00:10 -t 20 -i input.mp4 -c copy output.mp4

# First 60 seconds
ffmpeg -t 60 -i input.mp4 -c copy output.mp4

# Last 30 seconds (need duration first)
ffmpeg -sseof -30 -i input.mp4 -c copy output.mp4

Precise Cutting

# With re-encoding (more precise)
ffmpeg -ss 00:00:10 -i input.mp4 -t 20 -c:v libx264 -c:a aac output.mp4

# Keyframe-accurate (faster, may be less precise)
ffmpeg -ss 00:00:10 -i input.mp4 -t 20 -c copy output.mp4

Concatenation

Method 1: File List (Recommended)

# Create list.txt file:
# file 'video1.mp4'
# file 'video2.mp4'
# file 'video3.mp4'

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

Method 2: Same Codec Files

# If all videos have same codec/format
ffmpeg -i "concat:video1.mp4|video2.mp4|video3.mp4" -c copy output.mp4

Method 3: Re-encode (Different Codecs)

# Re-encode for compatibility
ffmpeg -f concat -safe 0 -i list.txt -c:v libx264 -c:a aac output.mp4

Splitting Video

# Split into 60-second segments
ffmpeg -i input.mp4 -c copy -f segment -segment_time 60 \
  -reset_timestamps 1 output_%03d.mp4

# Split at specific timestamps
ffmpeg -i input.mp4 -ss 00:00:00 -t 00:01:00 -c copy part1.mp4
ffmpeg -i input.mp4 -ss 00:01:00 -t 00:01:00 -c copy part2.mp4

Extract Segment with Re-encoding

# When you need to change quality/codec
ffmpeg -ss 00:00:10 -i input.mp4 -t 20 \
  -c:v libx264 -crf 23 -c:a aac -b:a 192k output.mp4

Multiple Segments

# Extract multiple segments
ffmpeg -i input.mp4 \
  -ss 00:00:10 -t 00:00:05 -c copy segment1.mp4 \
  -ss 00:01:00 -t 00:00:10 -c copy segment2.mp4

Notes

Use
```
-c copy
```
for speed (no re-encoding)
```
-ss
```
before
```
-i
```
is faster but less precise
```
-ss
```
after
```
-i
```
is more precise but slower
Concatenation requires same codec/format for
```
-c copy
```
Use file list method for best concatenation results