ffmpeg-patterns

name

ffmpeg-patterns

description

Advanced FFmpeg patterns for video production: encoding presets, lossless vs re-encode decisions, subtitle burn-in (SRT/ASS), audio mixing and ducking, face enhancement, silence removal, concatenation, format conversion, platform-specific encoding. Use for any FFmpeg operation beyond basic trim/cut. Keywords: ffmpeg, encoding, h264, crf, subtitle, burn-in, ASS, SRT, concat, audio mix, silence removal, face enhance, format, codec, bitrate, filter

FFmpeg Patterns for Video Production

Encoding Presets

Standard Quality (web delivery)

ffmpeg -i input.mp4 -c:v libx264 -crf 18 -preset medium -c:a aac -b:a 128k output.mp4

High Quality (master/archive)

ffmpeg -i input.mp4 -c:v libx264 -crf 15 -preset slow -c:a aac -b:a 256k output.mp4

Fast Preview

ffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset ultrafast -c:a aac -b:a 96k preview.mp4

Lossless vs Re-encode

• Use -c copy when you only need to cut or concat without altering frames (instant, lossless)
• Re-encode (-c:v libx264) when applying filters (speed, subtitles, overlays, scaling)
• Default CRF 23. Use 18-20 for higher quality final deliverables

Subtitle Burn-in

SRT (Simple)

ffmpeg -i input.mp4 -vf "subtitles=subs.srt:force_style='FontSize=22,Bold=1,PrimaryColour=&H00FFFFFF,OutlineColour=&H00000000,Outline=2'" output.mp4

ASS Color Format

Always use full 8-char &HAABBGGRR format: &H00FFFFFF (white, alpha=00)

• &HFFFFFF breaks positioning — always include the alpha byte

Vertical Video Subtitles

font_size: 18, max 3 words/cue, margin_v: 50

Horizontal Video Subtitles

font_size: 22, max 6 words/cue, margin_v: 40

Windows Path Escaping

Escape colons in paths: C\:/path/to/subs.srt not C:/path/to/subs.srt

Audio Operations

Mix Narration + Music (with ducking)

ffmpeg -i narration.wav -i music.wav -filter_complex \
  "[1:a]volume=0.15[music]; \
   [0:a][music]amix=inputs=2:duration=longest" \
  -c:a aac output.m4a

Loudness Normalization

ffmpeg -i input.mp4 -af loudnorm=I=-14:LRA=11:TP=-1 -c:v copy output.mp4

Extract Audio

ffmpeg -i video.mp4 -vn -c:a copy audio.m4a

Replace Audio

ffmpeg -i video.mp4 -i new_audio.wav -map 0:v -map 1:a -c:v copy -c:a aac output.mp4

Silence Removal

Detect Silence

ffmpeg -i input.mp4 -af "silencedetect=noise=-35dB:d=0.4" -f null - 2>&1 | grep silence

Remove Silence (trim + concat)

1. Parse silence_start / silence_end from stderr
2. Generate segments between silences
3. Concatenate with the concat demuxer
4. Optional: atempo=1.14 for slight speedup

Concatenation

Same Codec (lossless)

# Create filelist.txt:
# file 'clip1.mp4'
# file 'clip2.mp4'
ffmpeg -f concat -safe 0 -i filelist.txt -c copy output.mp4

Mixed Codecs (re-encode)

Re-encode all segments to matching codec/resolution first, then concat.

Speed Adjustment

Speed Up 2x

ffmpeg -i input.mp4 -filter:v "setpts=0.5*PTS" -filter:a "atempo=2.0" output.mp4

Slow Motion 0.5x

ffmpeg -i input.mp4 -filter:v "setpts=2.0*PTS" -filter:a "atempo=0.5" output.mp4

Face Enhancement Presets

Skin Smoothing

ffmpeg -i input.mp4 -vf "smartblur=lr=1.0:ls=-1.0:lt=-3.0:cr=0.5:cs=-1.0:ct=-3.0" output.mp4

Sharpening

ffmpeg -i input.mp4 -vf "unsharp=5:5:1.0:5:5:0.0" output.mp4

Format Conversion

To GIF (high quality)

ffmpeg -i input.mp4 -vf "fps=15,scale=480:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" output.gif

To WebM

ffmpeg -i input.mp4 -c:v libvpx-vp9 -crf 30 -b:v 0 -c:a libopus output.webm

Extract Frames

# Every 5 seconds
ffmpeg -i input.mp4 -vf "fps=1/5" frame_%04d.png

# Specific timestamp
ffmpeg -i input.mp4 -ss 00:01:30 -vframes 1 thumbnail.png

Probing (Analysis)

Full Media Info

ffprobe -v quiet -print_format json -show_format -show_streams input.mp4

Duration Only

ffprobe -v quiet -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 input.mp4

Audio Loudness

ffmpeg -i input.mp4 -af loudnorm=print_format=json -f null - 2>&1

Platform-Specific Encoding

Platform	Resolution	Codec	Bitrate
YouTube	1920x1080	H.264 High	8-12 Mbps
TikTok	1080x1920	H.264 High	8-15 Mbps
Instagram	1080x1920	H.264 High	8-15 Mbps
Twitter/X	1280x720	H.264 Main	5-8 Mbps

Windows-Specific Notes

• Always copy inputs to a temp directory first if paths contain spaces
• Use forward slashes in filter strings even on Windows
• Escape colons in drive letters within subtitle filter paths

---

Kolbo MCP Integration

FFmpeg is the post-production backbone that processes Kolbo-generated assets:

Kolbo MCP Output	FFmpeg Post-Processing
generate_video → raw video	Trim, grade, add subtitles, normalize audio
generate_speech → narration	Mix with music, normalize loudness
generate_music → background	Duck under narration, fade in/out
generate_sound → SFX	Place at precise timestamps, adjust levels
transcribe_audio → SRT	Burn-in subtitles with force_style
generate_image → frames	Assemble into slideshow/montage

Typical production chain:

Kolbo generates raw assets
  → FFmpeg trims/cuts
  → FFmpeg mixes audio (narration + music + SFX)
  → FFmpeg burns in subtitles
  → FFmpeg applies color grade
  → FFmpeg encodes for target platform

---

Installing FFmpeg

Windows:

# Scoop
scoop install ffmpeg

# Chocolatey
choco install ffmpeg

# Or download from https://ffmpeg.org/download.html

macOS:

brew install ffmpeg

Linux:

sudo apt install ffmpeg   # Ubuntu/Debian
sudo dnf install ffmpeg   # Fedora

Verify: ffmpeg -version