Ffmpeg

calesthio/OpenMontage/.agents/skills/ffmpeg

by calesthio9327439db69021ab4b0e2776729bf3b58fdb5a87No license65K starsListed Oct 9, 2026Updated Oct 9, 2026Repository updated 5 days ago

Video and audio processing with FFmpeg. Use for format conversion, resizing, compression, audio extraction, and preparing assets for Remotion. Triggers include converting GIF to MP4, resizing video, extracting audio, compressing files, or any media transformation task.

Instructions onlyDesign & Creative

AI-generated overview

Reference guide for using FFmpeg to convert, resize, compress, trim and prepare video and audio assets.

What it does: This skill is a command reference for FFmpeg and ffprobe covering media transformation tasks: GIF-to-MP4 conversion, resizing and padding, compression with CRF and preset settings, audio extraction and format conversion, trimming, speed changes, concatenation, fades and media inspection. It also documents Remotion-specific patterns such as preparing demo recordings and screen captures as assets, plus per-platform export presets for YouTube, Twitter/X, LinkedIn, web embeds and GIF previews. It includes troubleshooting notes for common errors and a quality-settings table.
When to use it: Use it when you need to convert, resize, compress, trim or extract audio from media files, or when preparing video assets for a Remotion project. It is also useful when producing platform-specific exports or diagnosing FFmpeg errors such as odd dimensions or unplayable output.
Requirements: Requires FFmpeg and ffprobe installed locally with the relevant codecs (for example libx264, libmp3lame, libvpx-vp9, libopus). No scripts are shipped; the skill contains instructions and command examples only. Network access is not required, though some examples reference downloading or uploading media.

FFmpeg for Video Production

FFmpeg is the essential tool for video/audio processing. This skill covers common operations for Remotion video projects.

Quick Reference

GIF to MP4 (Remotion-compatible)

bash

ffmpeg -i input.gif -movflags faststart -pix_fmt yuv420p \  -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" output.mp4

ffmpeg -i input.gif -movflags faststart -pix_fmt yuv420p \  -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" output.mp4

Why these flags:

-movflags faststart - Moves metadata to start for web streaming
-pix_fmt yuv420p - Ensures compatibility with most players
scale=trunc(...) - Forces even dimensions (required by most codecs)

Resize Video

bash

# To 1920x1080 (maintain aspect ratio, add black bars)ffmpeg -i input.mp4 -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2" output.mp4
# To 1920x1080 (crop to fill)ffmpeg -i input.mp4 -vf "scale=1920:1080:force_original_aspect_ratio=increase,crop=1920:1080" output.mp4
# Scale to width, auto heightffmpeg -i input.mp4 -vf "scale=1280:-2" output.mp4

# To 1920x1080 (maintain aspect ratio, add black bars)ffmpeg -i input.mp4 -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2" output.mp4
# To 1920x1080 (crop to fill)ffmpeg -i input.mp4 -vf "scale=1920:1080:force_original_aspect_ratio=increase,crop=1920:1080" output.mp4
# Scale to width, auto heightffmpeg -i input.mp4 -vf "scale=1280:-2" output.mp4

Compress Video

bash

# Good quality, smaller file (CRF 23 is default, lower = better quality)ffmpeg -i input.mp4 -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k output.mp4
# Aggressive compression for web previewffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset fast -c:a aac -b:a 96k output.mp4
# Target file size (e.g., ~10MB for 60s video = ~1.3Mbps)ffmpeg -i input.mp4 -c:v libx264 -b:v 1300k -c:a aac -b:a 128k output.mp4

# Good quality, smaller file (CRF 23 is default, lower = better quality)ffmpeg -i input.mp4 -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k output.mp4
# Aggressive compression for web previewffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset fast -c:a aac -b:a 96k output.mp4
# Target file size (e.g., ~10MB for 60s video = ~1.3Mbps)ffmpeg -i input.mp4 -c:v libx264 -b:v 1300k -c:a aac -b:a 128k output.mp4

Extract Audio

bash

# Extract to MP3ffmpeg -i input.mp4 -vn -acodec libmp3lame -q:a 2 output.mp3
# Extract to AACffmpeg -i input.mp4 -vn -acodec aac -b:a 192k output.m4a
# Extract to WAV (uncompressed)ffmpeg -i input.mp4 -vn output.wav

# Extract to MP3ffmpeg -i input.mp4 -vn -acodec libmp3lame -q:a 2 output.mp3
# Extract to AACffmpeg -i input.mp4 -vn -acodec aac -b:a 192k output.m4a
# Extract to WAV (uncompressed)ffmpeg -i input.mp4 -vn output.wav

Convert Audio Formats

bash

# M4A to MP3 (for ElevenLabs voice samples)ffmpeg -i input.m4a -codec:a libmp3lame -qscale:a 2 output.mp3
# WAV to MP3ffmpeg -i input.wav -codec:a libmp3lame -b:a 192k output.mp3
# Adjust volumeffmpeg -i input.mp3 -filter:a "volume=1.5" output.mp3

# M4A to MP3 (for ElevenLabs voice samples)ffmpeg -i input.m4a -codec:a libmp3lame -qscale:a 2 output.mp3
# WAV to MP3ffmpeg -i input.wav -codec:a libmp3lame -b:a 192k output.mp3
# Adjust volumeffmpeg -i input.mp3 -filter:a "volume=1.5" output.mp3

Trim/Cut Video

bash

# Cut from timestamp to duration (recommended - reliable)ffmpeg -i input.mp4 -ss 00:00:30 -t 00:00:15 -c:v libx264 -c:a aac output.mp4
# Cut from timestamp to timestampffmpeg -i input.mp4 -ss 00:00:30 -to 00:00:45 -c:v libx264 -c:a aac output.mp4
# Stream copy (faster but may lose frames at cut points)# Only use when source has frequent keyframesffmpeg -i input.mp4 -ss 00:00:30 -t 00:00:15 -c copy output.mp4

# Cut from timestamp to duration (recommended - reliable)ffmpeg -i input.mp4 -ss 00:00:30 -t 00:00:15 -c:v libx264 -c:a aac output.mp4
# Cut from timestamp to timestampffmpeg -i input.mp4 -ss 00:00:30 -to 00:00:45 -c:v libx264 -c:a aac output.mp4
# Stream copy (faster but may lose frames at cut points)# Only use when source has frequent keyframesffmpeg -i input.mp4 -ss 00:00:30 -t 00:00:15 -c copy output.mp4

Note: Re-encoding is recommended for trimming. Stream copy (-c copy) can silently drop video if the seek point doesn't align with a keyframe.

Speed Up / Slow Down

bash

# 2x speed (video and audio)ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" output.mp4
# 0.5x speed (slow motion)ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=2.0*PTS[v];[0:a]atempo=0.5[a]" -map "[v]" -map "[a]" output.mp4
# Video only (no audio)ffmpeg -i input.mp4 -filter:v "setpts=0.5*PTS" -an output.mp4

# 2x speed (video and audio)ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" output.mp4
# 0.5x speed (slow motion)ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=2.0*PTS[v];[0:a]atempo=0.5[a]" -map "[v]" -map "[a]" output.mp4
# Video only (no audio)ffmpeg -i input.mp4 -filter:v "setpts=0.5*PTS" -an output.mp4

Concatenate Videos

bash

# Create file listecho "file 'clip1.mp4'" > list.txtecho "file 'clip2.mp4'" >> list.txtecho "file 'clip3.mp4'" >> list.txt
# Concatenate (same codec/resolution)ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4
# Concatenate with re-encoding (different sources)ffmpeg -f concat -safe 0 -i list.txt -c:v libx264 -c:a aac output.mp4

# Create file listecho "file 'clip1.mp4'" > list.txtecho "file 'clip2.mp4'" >> list.txtecho "file 'clip3.mp4'" >> list.txt
# Concatenate (same codec/resolution)ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4
# Concatenate with re-encoding (different sources)ffmpeg -f concat -safe 0 -i list.txt -c:v libx264 -c:a aac output.mp4

Add Fade In/Out

bash

# Fade in first 1 second, fade out last 1 second (30fps video)ffmpeg -i input.mp4 -vf "fade=t=in:st=0:d=1,fade=t=out:st=9:d=1" -c:a copy output.mp4
# Audio fadeffmpeg -i input.mp4 -af "afade=t=in:st=0:d=1,afade=t=out:st=9:d=1" -c:v copy output.mp4

# Fade in first 1 second, fade out last 1 second (30fps video)ffmpeg -i input.mp4 -vf "fade=t=in:st=0:d=1,fade=t=out:st=9:d=1" -c:a copy output.mp4
# Audio fadeffmpeg -i input.mp4 -af "afade=t=in:st=0:d=1,afade=t=out:st=9:d=1" -c:v copy output.mp4

Get Video Info

bash

# Duration, resolution, codec infoffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 input.mp4
# Full infoffprobe -v quiet -print_format json -show_format -show_streams input.mp4

# Duration, resolution, codec infoffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 input.mp4
# Full infoffprobe -v quiet -print_format json -show_format -show_streams input.mp4

Remotion-Specific Patterns

Video Speed Adjustment for Remotion

When to use FFmpeg vs Remotion playbackRate:

Scenario	Use FFmpeg	Use Remotion
Constant speed (1.5x, 2x)	Either works	✅ Simpler
Extreme speeds (>4x or <0.25x)	✅ More reliable	May have issues
Variable speed (accelerate over time)	✅ Pre-process	Complex workaround needed
Need perfect audio sync	✅ Guaranteed	Usually fine
Demo needs to fit voiceover timing	✅ Pre-calculate	Runtime adjustment

Remotion limitation: playbackRate must be constant. Dynamic interpolation like playbackRate={interpolate(frame, [0, 100], [1, 5])} won't work correctly because Remotion evaluates frames independently.

bash

# Speed up demo to fit a scene (e.g., 60s demo into 20s = 3x speed)ffmpeg -i demo-raw.mp4 \  -filter_complex "[0:v]setpts=0.333*PTS[v];[0:a]atempo=3.0[a]" \  -map "[v]" -map "[a]" \  public/demos/demo-fast.mp4
# Slow motion for emphasis (0.5x speed)ffmpeg -i action.mp4 \  -filter_complex "[0:v]setpts=2.0*PTS[v];[0:a]atempo=0.5[a]" \  -map "[v]" -map "[a]" \  public/demos/action-slow.mp4
# Speed up without audio (common for screen recordings)ffmpeg -i demo.mp4 -filter:v "setpts=0.5*PTS" -an public/demos/demo-2x.mp4
# Timelapse effect (10x speed, drop audio)ffmpeg -i long-demo.mp4 -filter:v "setpts=0.1*PTS" -an public/demos/timelapse.mp4

# Speed up demo to fit a scene (e.g., 60s demo into 20s = 3x speed)ffmpeg -i demo-raw.mp4 \  -filter_complex "[0:v]setpts=0.333*PTS[v];[0:a]atempo=3.0[a]" \  -map "[v]" -map "[a]" \  public/demos/demo-fast.mp4
# Slow motion for emphasis (0.5x speed)ffmpeg -i action.mp4 \  -filter_complex "[0:v]setpts=2.0*PTS[v];[0:a]atempo=0.5[a]" \  -map "[v]" -map "[a]" \  public/demos/action-slow.mp4
# Speed up without audio (common for screen recordings)ffmpeg -i demo.mp4 -filter:v "setpts=0.5*PTS" -an public/demos/demo-2x.mp4
# Timelapse effect (10x speed, drop audio)ffmpeg -i long-demo.mp4 -filter:v "setpts=0.1*PTS" -an public/demos/timelapse.mp4

Calculate speed factor:

To fit X seconds of video into Y seconds of scene: speed = X / Y
setpts multiplier = 1 / speed (e.g., 3x speed = setpts=0.333*PTS)
atempo value = speed (e.g., 3x speed = atempo=3.0)

Extreme speed (>2x audio): Chain atempo filters (each limited to 0.5-2.0 range):

bash

# 4x speed audio-filter_complex "[0:a]atempo=2.0,atempo=2.0[a]"
# 8x speed audio-filter_complex "[0:a]atempo=2.0,atempo=2.0,atempo=2.0[a]"

# 4x speed audio-filter_complex "[0:a]atempo=2.0,atempo=2.0[a]"
# 8x speed audio-filter_complex "[0:a]atempo=2.0,atempo=2.0,atempo=2.0[a]"

Prepare Demo Recording for Remotion

bash

# Standard 1080p, 30fps, Remotion-readyffmpeg -i raw-recording.mp4 \  -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,fps=30" \  -c:v libx264 -crf 18 -preset slow \  -c:a aac -b:a 192k \  -movflags faststart \  public/demos/demo.mp4

# Standard 1080p, 30fps, Remotion-readyffmpeg -i raw-recording.mp4 \  -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,fps=30" \  -c:v libx264 -crf 18 -preset slow \  -c:a aac -b:a 192k \  -movflags faststart \  public/demos/demo.mp4

Screen Recording to Remotion Asset

bash

# From iPhone/iPad recording (usually 60fps, variable resolution)ffmpeg -i iphone-recording.mov \  -vf "scale=1920:-2,fps=30" \  -c:v libx264 -crf 20 \  -an \  public/demos/mobile-demo.mp4

# From iPhone/iPad recording (usually 60fps, variable resolution)ffmpeg -i iphone-recording.mov \  -vf "scale=1920:-2,fps=30" \  -c:v libx264 -crf 20 \  -an \  public/demos/mobile-demo.mp4

Batch Convert GIFs

bash

for f in assets/*.gif; do  ffmpeg -i "$f" -movflags faststart -pix_fmt yuv420p \    -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" \    "public/demos/$(basename "$f" .gif).mp4"done

for f in assets/*.gif; do  ffmpeg -i "$f" -movflags faststart -pix_fmt yuv420p \    -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" \    "public/demos/$(basename "$f" .gif).mp4"done

Common Issues

"Height not divisible by 2"

Add scale filter: -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2"

Video won't play in browser

Use: -movflags faststart -pix_fmt yuv420p -c:v libx264

Audio out of sync after speed change

Use filter_complex with atempo: -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]"

File too large

Increase CRF (23→28) or reduce resolution

Quality Guidelines

Platform-Specific Output Optimization

After Remotion renders your video (typically to out/video.mp4), use FFmpeg to optimize for each distribution platform.

Workflow Integration

Remotion render (master)     FFmpeg optimization      Platform upload       ↓                            ↓                       ↓   out/video.mp4  ────────→  out/video-youtube.mp4  ───→  YouTube                  ────────→  out/video-twitter.mp4  ───→  Twitter/X                  ────────→  out/video-linkedin.mp4 ───→  LinkedIn                  ────────→  out/video-web.mp4      ───→  Website embed

Remotion render (master)     FFmpeg optimization      Platform upload       ↓                            ↓                       ↓   out/video.mp4  ────────→  out/video-youtube.mp4  ───→  YouTube                  ────────→  out/video-twitter.mp4  ───→  Twitter/X                  ────────→  out/video-linkedin.mp4 ───→  LinkedIn                  ────────→  out/video-web.mp4      ───→  Website embed

YouTube (Recommended Settings)

YouTube re-encodes everything, so upload high quality:

bash

# YouTube optimized (1080p)ffmpeg -i out/video.mp4 \  -c:v libx264 -preset slow -crf 18 \  -profile:v high -level 4.0 \  -bf 2 -g 30 \  -c:a aac -b:a 192k -ar 48000 \  -movflags +faststart \  out/video-youtube.mp4
# YouTube Shorts (vertical 1080x1920)ffmpeg -i out/video.mp4 \  -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2" \  -c:v libx264 -crf 18 -c:a aac -b:a 192k \  out/video-shorts.mp4

# YouTube optimized (1080p)ffmpeg -i out/video.mp4 \  -c:v libx264 -preset slow -crf 18 \  -profile:v high -level 4.0 \  -bf 2 -g 30 \  -c:a aac -b:a 192k -ar 48000 \  -movflags +faststart \  out/video-youtube.mp4
# YouTube Shorts (vertical 1080x1920)ffmpeg -i out/video.mp4 \  -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2" \  -c:v libx264 -crf 18 -c:a aac -b:a 192k \  out/video-shorts.mp4

Twitter/X

Twitter has strict limits: max 140s, 512MB, 1920x1200:

bash

# Twitter optimized (under 15MB target for fast upload)ffmpeg -i out/video.mp4 \  -c:v libx264 -preset medium -crf 24 \  -profile:v main -level 3.1 \  -vf "scale='min(1280,iw)':'min(720,ih)':force_original_aspect_ratio=decrease" \  -c:a aac -b:a 128k -ar 44100 \  -movflags +faststart \  -fs 15M \  out/video-twitter.mp4
# Check file size and durationffprobe -v error -show_entries format=duration,size -of csv=p=0 out/video-twitter.mp4

# Twitter optimized (under 15MB target for fast upload)ffmpeg -i out/video.mp4 \  -c:v libx264 -preset medium -crf 24 \  -profile:v main -level 3.1 \  -vf "scale='min(1280,iw)':'min(720,ih)':force_original_aspect_ratio=decrease" \  -c:a aac -b:a 128k -ar 44100 \  -movflags +faststart \  -fs 15M \  out/video-twitter.mp4
# Check file size and durationffprobe -v error -show_entries format=duration,size -of csv=p=0 out/video-twitter.mp4

LinkedIn prefers MP4 with AAC audio, max 10 minutes:

bash

# LinkedIn optimizedffmpeg -i out/video.mp4 \  -c:v libx264 -preset medium -crf 22 \  -profile:v main \  -vf "scale='min(1920,iw)':'min(1080,ih)':force_original_aspect_ratio=decrease" \  -c:a aac -b:a 192k -ar 48000 \  -movflags +faststart \  out/video-linkedin.mp4

# LinkedIn optimizedffmpeg -i out/video.mp4 \  -c:v libx264 -preset medium -crf 22 \  -profile:v main \  -vf "scale='min(1920,iw)':'min(1080,ih)':force_original_aspect_ratio=decrease" \  -c:a aac -b:a 192k -ar 48000 \  -movflags +faststart \  out/video-linkedin.mp4

Website/Embed (Optimized for Fast Loading)

bash

# Web-optimized MP4 (small file, progressive loading)ffmpeg -i out/video.mp4 \  -c:v libx264 -preset medium -crf 26 \  -profile:v baseline -level 3.0 \  -vf "scale=1280:720" \  -c:a aac -b:a 128k \  -movflags +faststart \  out/video-web.mp4
# WebM alternative (better compression, wider browser support)ffmpeg -i out/video.mp4 \  -c:v libvpx-vp9 -crf 30 -b:v 0 \  -vf "scale=1280:720" \  -c:a libopus -b:a 128k \  -deadline good \  out/video-web.webm

# Web-optimized MP4 (small file, progressive loading)ffmpeg -i out/video.mp4 \  -c:v libx264 -preset medium -crf 26 \  -profile:v baseline -level 3.0 \  -vf "scale=1280:720" \  -c:a aac -b:a 128k \  -movflags +faststart \  out/video-web.mp4
# WebM alternative (better compression, wider browser support)ffmpeg -i out/video.mp4 \  -c:v libvpx-vp9 -crf 30 -b:v 0 \  -vf "scale=1280:720" \  -c:a libopus -b:a 128k \  -deadline good \  out/video-web.webm

GIF (for Previews/Thumbnails)

bash

# High-quality GIF (first 5 seconds)ffmpeg -i out/video.mp4 -t 5 \  -vf "fps=15,scale=480:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" \  out/preview.gif
# Smaller file GIFffmpeg -i out/video.mp4 -t 3 \  -vf "fps=10,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" \  out/preview-small.gif

# High-quality GIF (first 5 seconds)ffmpeg -i out/video.mp4 -t 5 \  -vf "fps=15,scale=480:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" \  out/preview.gif
# Smaller file GIFffmpeg -i out/video.mp4 -t 3 \  -vf "fps=10,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" \  out/preview-small.gif

Platform Requirements Quick Reference

Platform	Max Resolution	Max Size	Max Duration	Audio
YouTube	8K	256GB	12 hours	AAC 48kHz
Twitter/X	1920x1200	512MB	140s	AAC 44.1kHz
LinkedIn	4096x2304	5GB	10 min	AAC 48kHz
Instagram Feed	1080x1350	4GB	60s	AAC 48kHz
Instagram Reels	1080x1920	4GB	90s	AAC 48kHz
TikTok	1080x1920	287MB	10 min	AAC

Batch Export for All Platforms

bash

#!/bin/bash# save as: export-all-platforms.shINPUT="out/video.mp4"
# YouTube (high quality)ffmpeg -i "$INPUT" -c:v libx264 -preset slow -crf 18 \  -c:a aac -b:a 192k -movflags +faststart \  out/video-youtube.mp4
# Twitter (compressed)ffmpeg -i "$INPUT" -c:v libx264 -crf 24 \  -vf "scale='min(1280,iw)':'-2'" \  -c:a aac -b:a 128k -movflags +faststart \  out/video-twitter.mp4
# LinkedInffmpeg -i "$INPUT" -c:v libx264 -crf 22 \  -c:a aac -b:a 192k -movflags +faststart \  out/video-linkedin.mp4
# Web embed (small)ffmpeg -i "$INPUT" -c:v libx264 -crf 26 \  -vf "scale=1280:720" \  -c:a aac -b:a 128k -movflags +faststart \  out/video-web.mp4
echo "Exported:"ls -lh out/video-*.mp4

#!/bin/bash# save as: export-all-platforms.shINPUT="out/video.mp4"
# YouTube (high quality)ffmpeg -i "$INPUT" -c:v libx264 -preset slow -crf 18 \  -c:a aac -b:a 192k -movflags +faststart \  out/video-youtube.mp4
# Twitter (compressed)ffmpeg -i "$INPUT" -c:v libx264 -crf 24 \  -vf "scale='min(1280,iw)':'-2'" \  -c:a aac -b:a 128k -movflags +faststart \  out/video-twitter.mp4
# LinkedInffmpeg -i "$INPUT" -c:v libx264 -crf 22 \  -c:a aac -b:a 192k -movflags +faststart \  out/video-linkedin.mp4
# Web embed (small)ffmpeg -i "$INPUT" -c:v libx264 -crf 26 \  -vf "scale=1280:720" \  -c:a aac -b:a 128k -movflags +faststart \  out/video-web.mp4
echo "Exported:"ls -lh out/video-*.mp4

Error Handling

Common errors and fixes when processing video:

bash

# Check if FFmpeg succeededffmpeg -i input.mp4 -c:v libx264 output.mp4 && echo "Success" || echo "Failed: check input file"
# Validate output file is playableffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of csv=p=0 output.mp4
# Get detailed error infoffmpeg -v error -i input.mp4 -f null - 2>&1 | head -20

# Check if FFmpeg succeededffmpeg -i input.mp4 -c:v libx264 output.mp4 && echo "Success" || echo "Failed: check input file"
# Validate output file is playableffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of csv=p=0 output.mp4
# Get detailed error infoffmpeg -v error -i input.mp4 -f null - 2>&1 | head -20

Handling Common Failures

Error	Cause	Fix
"No such file"	Input path wrong	Check path, use quotes for spaces
"Invalid data"	Corrupted input	Re-download or re-record source
"height not divisible by 2"	Odd dimensions	Add scale filter with trunc
"encoder not found"	Missing codec	Install FFmpeg with full codecs
Output 0 bytes	Silent failure	Check full ffmpeg output for errors

Feedback & Contributions

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Just say "improve this skill" and I'll guide you through updating .claude/skills/ffmpeg/SKILL.md.

Source and attribution

Source:calesthio/OpenMontagein.agents/skills/ffmpegat commit9327439

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Use Case	CRF	Preset	Notes
Archive/Master	18	slow	Best quality, large files
Production	20-22	medium	Good balance
Web/Preview	23-25	fast	Smaller files
Draft/Quick	28+	veryfast	Fast encoding

Ffmpeg

FFmpeg for Video Production

Quick Reference

GIF to MP4 (Remotion-compatible)

Resize Video

Compress Video

Extract Audio

Convert Audio Formats

Trim/Cut Video

Speed Up / Slow Down

Concatenate Videos

Add Fade In/Out

Get Video Info

Remotion-Specific Patterns

Video Speed Adjustment for Remotion

Prepare Demo Recording for Remotion

Screen Recording to Remotion Asset

Batch Convert GIFs

Common Issues

"Height not divisible by 2"

Video won't play in browser

Audio out of sync after speed change

File too large

Quality Guidelines

Platform-Specific Output Optimization

Workflow Integration

YouTube (Recommended Settings)

Twitter/X

LinkedIn

Website/Embed (Optimized for Fast Loading)

GIF (for Previews/Thumbnails)

Platform Requirements Quick Reference

Batch Export for All Platforms

Error Handling

Handling Common Failures

Feedback & Contributions

Source and attribution

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