AgentSkillsCN

ffmpeg-video-editor-h265

根据自然语言的视频编辑需求，生成FFmpeg命令——剪切、裁剪、转换、压缩、调整宽高比、提取音频，以及更多操作。

SKILL.md
--- frontmatter
name: ffmpeg-video-editor-h265
description: Generate FFmpeg commands from natural language video editing requests - cut, trim, convert, compress, change aspect ratio, extract audio, and more.
forked and modified from: https://clawhub.ai/MahmoudAdelbghany/ffmpeg-video-editor

FFmpeg Video Editor

You are a video editing assistant that translates natural language requests into FFmpeg commands. When the user asks to edit a video, generate the correct FFmpeg command.

How to Generate Commands

  1. •Identify the operation from the user's request
  2. •Extract parameters (input file, output file, timestamps, formats, etc.)
  3. •Generate the FFmpeg command using the patterns below
  4. •If output filename not specified, create one based on the operation (e.g., video_trimmed.mp4)
  5. •Always include -y (overwrite) and -hide_banner for cleaner output

Command Reference

Cut/Trim Video

Extract a portion of video between two timestamps.

User might say: "cut video.mp4 from 1:21 to 1:35", "trim first 30 seconds", "extract 0:05:00 to 0:10:30"

Command:

bash
ffmpeg -y -hide_banner -i "INPUT" -ss START_TIME -to END_TIME -c copy "OUTPUT"

Examples:

  • •Cut from 1:21 to 1:35:
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -ss 00:01:21 -to 00:01:35 -c copy "video_trimmed.mp4"
  • •Extract first 2 minutes:
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -ss 00:00:00 -to 00:02:00 -c copy "video_clip.mp4"

Format Conversion

Convert between video formats: mp4, mkv, avi, webm, mov, flv, wmv.

User might say: "convert to mkv", "change format from avi to mp4", "make it a webm"

Commands by format:

bash
# MP4 (most compatible)
ffmpeg -y -hide_banner -i "INPUT" -c:v libx264 -c:a aac "OUTPUT.mp4"

# MKV (lossless container change)
ffmpeg -y -hide_banner -i "INPUT" -c copy "OUTPUT.mkv"

# WebM (web optimized)
ffmpeg -y -hide_banner -i "INPUT" -c:v libvpx-vp9 -c:a libopus "OUTPUT.webm"

# AVI
ffmpeg -y -hide_banner -i "INPUT" -c:v mpeg4 -c:a mp3 "OUTPUT.avi"

# MOV
ffmpeg -y -hide_banner -i "INPUT" -c:v libx264 -c:a aac "OUTPUT.mov"

Change Aspect Ratio

Resize video to different aspect ratios with letterboxing (black bars).

User might say: "change aspect ratio to 16:9", "make it square", "vertical for TikTok"

Common aspect ratios:

RatioResolutionUse Case
16:91920x1080YouTube, TV
4:31440x1080Old TV format
1:11080x1080Instagram square
9:161080x1920TikTok, Reels, Stories
21:92560x1080Ultrawide/Cinema

Command (with letterboxing):

bash
ffmpeg -y -hide_banner -i "INPUT" -vf "scale=WIDTH:HEIGHT:force_original_aspect_ratio=decrease,pad=WIDTH:HEIGHT:(ow-iw)/2:(oh-ih)/2:black" -c:a copy "OUTPUT"

Examples:

  • •16:9 for YouTube:
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black" -c:a copy "video_16x9.mp4"
  • •Square for Instagram:
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -vf "scale=1080:1080:force_original_aspect_ratio=decrease,pad=1080:1080:(ow-iw)/2:(oh-ih)/2:black" -c:a copy "video_square.mp4"
  • •Vertical for TikTok:
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2:black" -c:a copy "video_vertical.mp4"

Change Resolution

Resize video to standard resolutions.

User might say: "resize to 720p", "make it 4K", "downscale to 480p"

Resolutions:

NameDimensions
4K3840x2160
1080p1920x1080
720p1280x720
480p854x480
360p640x360

Command:

bash
ffmpeg -y -hide_banner -i "INPUT" -vf "scale=WIDTH:HEIGHT" -c:a copy "OUTPUT"

Example - Resize to 720p:

bash
ffmpeg -y -hide_banner -i "video.mp4" -vf "scale=1280:720" -c:a copy "video_720p.mp4"

Compress Video

Reduce file size. Default compression codec is H.265 (libx265). For H.265, CRF controls quality/size: 20 (high quality) → 32 (smaller files), 28 is balanced.

User might say: "compress video", "reduce file size", "make smaller for email"

Command:

bash
ffmpeg -y -hide_banner -i "INPUT" -c:v libx265 -tag:v hvc1 -crf CRF_VALUE -preset medium -c:a aac -b:a 128k "OUTPUT"

Examples:

  • •Balanced compression (CRF 28):
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -c:v libx265 -tag:v hvc1 -crf 28 -preset medium -c:a aac -b:a 128k "video_compressed.mp4"
  • •High compression/smaller file (CRF 32):
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -c:v libx265 -tag:v hvc1 -crf 32 -preset fast -c:a aac -b:a 96k "video_small.mp4"
  • •High quality (CRF 20):
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -c:v libx265 -tag:v hvc1 -crf 20 -preset slow -c:a aac -b:a 192k "video_hq.mp4"

Extract Audio

Extract audio track from video.

User might say: "extract audio as mp3", "get the audio from video", "convert to audio only"

Command:

bash
ffmpeg -y -hide_banner -i "INPUT" -vn -acodec CODEC "OUTPUT.FORMAT"

Codecs by format:

FormatCodec
mp3libmp3lame
aacaac
wavpcm_s16le
flacflac
ogglibvorbis

Example - Extract as MP3:

bash
ffmpeg -y -hide_banner -i "video.mp4" -vn -acodec libmp3lame "video.mp3"

Remove Audio

Create silent video (remove audio track).

User might say: "remove audio", "mute video", "make silent"

Command:

bash
ffmpeg -y -hide_banner -i "INPUT" -an -c:v copy "OUTPUT"

Example:

bash
ffmpeg -y -hide_banner -i "video.mp4" -an -c:v copy "video_silent.mp4"

Change Speed

Speed up or slow down video.

User might say: "speed up 2x", "slow motion", "make 10x timelapse"

Command:

bash
# Speed up (e.g., 2x speed)
ffmpeg -y -hide_banner -i "INPUT" -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" "OUTPUT"

# Slow down (e.g., 0.5x speed / half speed)
ffmpeg -y -hide_banner -i "INPUT" -filter_complex "[0:v]setpts=2.0*PTS[v];[0:a]atempo=0.5[a]" -map "[v]" -map "[a]" "OUTPUT"

Formula:

  • •Video: setpts = (1/speed)*PTS (2x speed → 0.5*PTS)
  • •Audio: atempo = speed (must be 0.5-2.0, chain for extremes)

Examples:

  • •2x speed:
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" "video_2x.mp4"
  • •Half speed (slow motion):
    bash
    ffmpeg -y -hide_banner -i "video.mp4" -filter_complex "[0:v]setpts=2.0*PTS[v];[0:a]atempo=0.5[a]" -map "[v]" -map "[a]" "video_slowmo.mp4"

Convert to GIF

Create animated GIF from video.

User might say: "make a gif", "convert to gif", "gif from 0:10 to 0:15"

Command:

bash
ffmpeg -y -hide_banner -i "INPUT" -ss START -t DURATION -vf "fps=15,scale=480:-1:flags=lanczos" -loop 0 "OUTPUT.gif"

Example - GIF of 5 seconds starting at 0:10:

bash
ffmpeg -y -hide_banner -i "video.mp4" -ss 00:00:10 -t 5 -vf "fps=15,scale=480:-1:flags=lanczos" -loop 0 "video.gif"

Rotate/Flip Video

Rotate or flip video orientation.

User might say: "rotate 90 degrees", "flip horizontally", "rotate upside down"

Commands:

bash
# Rotate 90° clockwise
ffmpeg -y -hide_banner -i "INPUT" -vf "transpose=1" -c:a copy "OUTPUT"

# Rotate 90° counter-clockwise
ffmpeg -y -hide_banner -i "INPUT" -vf "transpose=2" -c:a copy "OUTPUT"

# Rotate 180°
ffmpeg -y -hide_banner -i "INPUT" -vf "transpose=2,transpose=2" -c:a copy "OUTPUT"

# Flip horizontal (mirror)
ffmpeg -y -hide_banner -i "INPUT" -vf "hflip" -c:a copy "OUTPUT"

# Flip vertical
ffmpeg -y -hide_banner -i "INPUT" -vf "vflip" -c:a copy "OUTPUT"

Extract Screenshot/Frame

Capture a single frame from video.

User might say: "screenshot at 1:30", "extract thumbnail", "get frame at 5 seconds"

Command:

bash
ffmpeg -y -hide_banner -i "INPUT" -ss TIMESTAMP -frames:v 1 "OUTPUT.jpg"

Example:

bash
ffmpeg -y -hide_banner -i "video.mp4" -ss 00:01:30 -frames:v 1 "screenshot.jpg"

Add Watermark/Logo

Overlay image on video.

User might say: "add logo.png", "put watermark in corner", "overlay image"

Positions:

PositionOverlay Value
Top-leftoverlay=10:10
Top-rightoverlay=W-w-10:10
Bottom-leftoverlay=10:H-h-10
Bottom-rightoverlay=W-w-10:H-h-10
Centeroverlay=(W-w)/2:(H-h)/2

Command:

bash
ffmpeg -y -hide_banner -i "VIDEO" -i "LOGO" -filter_complex "overlay=POSITION" "OUTPUT"

Example - Logo in top-right:

bash
ffmpeg -y -hide_banner -i "video.mp4" -i "logo.png" -filter_complex "overlay=W-w-10:10" "video_watermarked.mp4"

Burn Subtitles

Permanently embed subtitles into video.

User might say: "add subtitles", "burn srt file", "embed captions"

Command:

bash
ffmpeg -y -hide_banner -i "INPUT" -vf "subtitles='SUBTITLE_FILE'" "OUTPUT"

Example:

bash
ffmpeg -y -hide_banner -i "video.mp4" -vf "subtitles='subtitles.srt'" "video_subtitled.mp4"

Merge/Concatenate Videos

Join multiple videos together.

User might say: "merge video1 and video2", "combine clips", "join intro and main"

Method: First create a text file listing videos, then concatenate.

Step 1 - Create file list (files.txt):

code
file 'video1.mp4'
file 'video2.mp4'
file 'video3.mp4'

Step 2 - Concatenate:

bash
ffmpeg -y -hide_banner -f concat -safe 0 -i files.txt -c copy "merged.mp4"

Time Format Reference

Use these formats for timestamps:

  • •HH:MM:SS → 01:30:45 (1 hour 30 min 45 sec)
  • •MM:SS → 05:30 (5 min 30 sec)
  • •SS → 90 (90 seconds)
  • •HH:MM:SS.mmm → 00:01:23.500 (with milliseconds)

Response Format

When generating commands:

  1. •Show the FFmpeg command in a code block
  2. •Briefly explain what it does
  3. •Mention if output filename was assumed

Example response:

code
Here's the command to cut your video from 1:21 to 1:35:

​```bash
ffmpeg -y -hide_banner -i "video.mp4" -ss 00:01:21 -to 00:01:35 -c copy "video_trimmed.mp4"
​```

This extracts the segment without re-encoding (using `-c copy` for speed). Output saved as `video_trimmed.mp4`.