FFmpeg CLI
Overview
Execute FFmpeg command-line operations to process video, audio, and image files. This skill provides comprehensive FFmpeg workflows for 13 common multimedia processing tasks, from basic format conversion to advanced video editing with transitions and overlays.
Prerequisites
Verify FFmpeg installation before proceeding:
ffmpeg -version
Minimum version: FFmpeg 4.3+ (for xfade transitions) Common installation:
- macOS:
brew install ffmpeg - Linux:
apt-get install ffmpegoryum install ffmpeg - Windows: Download from ffmpeg.org
Official CLI Syntax
Command Structure
ffmpeg [global_options] {[input_file_options] -i input_url} ... {[output_file_options] output_url} ...
Critical Rule: Options are positional. Input options apply ONLY to the next
-i. Output options apply ONLY to the next output file. Misordering options causes silent misbehavior.
# CORRECT: -ss seeks input (fast), -t limits output duration
ffmpeg -y -ss 5 -i input.mp4 -t 10 -c:v libx264 output.mp4
# ^ ^ ^ ^
# | input option output options output file
# global option
# DIFFERENT BEHAVIOR: -ss after -i seeks output (slow but accurate)
ffmpeg -y -i input.mp4 -ss 5 -t 10 -c:v libx264 output.mp4
Stream Specifiers
Target specific streams with -option:stream_specifier:
| Pattern | Meaning | Example |
|---|---|---|
v |
All video streams | -c:v libx264 |
a |
All audio streams | -c:a aac |
s |
All subtitle streams | -c:s mov_text |
v:0 |
First video stream | -b:v:0 2M |
a:1 |
Second audio stream | -c:a:1 copy |
Stream Mapping
# Without -map: auto-selects best video + best audio + first subtitle
ffmpeg -i input.mp4 output.mp4
# With -map: auto-selection DISABLED — must map ALL desired streams
ffmpeg -i input.mp4 -map 0:v -map 0:a output.mp4
# Multiple inputs: video from first, audio from second
ffmpeg -i video.mp4 -i audio.mp3 -map 0:v -map 1:a output.mp4
Gotcha: Using
-maponce disables auto-selection. Forgetting to map audio = silent output.
Seeking Behavior
| Position | Speed | Accuracy | Use Case |
|---|---|---|---|
-ss before -i |
Fast (keyframe seek) | Approximate | Stream copy, rough cuts |
-ss after -i |
Slow (decode & discard) | Frame-exact | Precise editing |
| Both combined | Fast + Accurate | Best of both | Recommended for re-encode |
# Fast seeking (good with -c copy)
ffmpeg -ss 30 -i input.mp4 -t 10 -c copy output.mp4
# Accurate seeking (re-encode required)
ffmpeg -i input.mp4 -ss 30 -t 10 -c:v libx264 -c:a aac output.mp4
# Combined: fast jump + fine-tune
ffmpeg -ss 29 -i input.mp4 -ss 1 -t 10 -c:v libx264 -c:a aac output.mp4
Stream Copy vs Re-encoding
-c copy |
Re-encode (-c:v libx264) |
|
|---|---|---|
| Speed | Very fast | Slow |
| Quality | Lossless (original) | Depends on settings |
| Filters | Cannot use | Required for filters |
| Cut accuracy | Keyframe only | Frame-exact |
# Stream copy (fast, no quality loss, no filters)
ffmpeg -i input.mp4 -c copy output.mp4
# Re-encode video only (allows video filters, copies audio)
ffmpeg -i input.mp4 -vf "scale=1280:720" -c:v libx264 -c:a copy output.mp4
Common Patterns
Copy without re-encoding (fast):
ffmpeg -i input.mp4 -c copy output.mp4
Re-encode with quality control:
ffmpeg -i input.mp4 -c:v libx264 -crf 23 -c:a aac output.mp4
Apply video filter:
ffmpeg -i input.mp4 -vf "filter_name=param=value" -c:a copy output.mp4
Complex filter graph:
ffmpeg -i input1.mp4 -i input2.mp4 \
-filter_complex "[0:v][1:v]filter_name[out]" \
-map "[out]" -map 0:a output.mp4
Core Operations
1. Add Text to Video
Add text overlays with full control over font, size, color, position, and timing.
Basic text overlay:
ffmpeg -i input.mp4 \
-vf "drawtext=fontfile=/path/to/font.ttf:text='Hello World':fontsize=48:fontcolor=white:x=(w-text_w)/2:y=h-th-20" \
-c:a copy output.mp4
Parameters:
fontfile- Path to TrueType font file (required)text- Text content (escape single quotes:don''t)fontsize- Font size in pixels (default: 16)fontcolor- Color name or hex valuex,y- Position (numbers or expressions)enable- Time control:'between(t,5,10)'
Position expressions:
(w-text_w)/2- center horizontally(h-text_h)/2- center vertically10- 10px from left/top edgew-text_w-10- 10px from right edgeh-th-20- 20px from bottom edge
Text with background box:
ffmpeg -i input.mp4 \
-vf "drawtext=fontfile=/path/to/font.ttf:text='Subtitle':fontsize=48:fontcolor=white:x=(w-text_w)/2:y=h-th-20:box=1:boxcolor=black@0.5:boxborderw=5" \
-c:a copy output.mp4
Timed text (show from 5 to 10 seconds):
ffmpeg -i input.mp4 \
-vf "drawtext=fontfile=/path/to/font.ttf:text='Limited':fontsize=48:fontcolor=white:x=(w-text_w)/2:y=(h-text_h)/2:enable='between(t,5,10)'" \
-c:a copy output.mp4
2. Add Subtitles from SRT File
Burn subtitles from SRT file into video.
Method 1: Using subtitles filter (recommended):
ffmpeg -i input.mp4 -vf "subtitles=subtitle.srt" -c:a copy output.mp4
Method 2: Custom styling with drawtext (programmatic):
Parse SRT file and generate drawtext filter chain for each subtitle entry. Each entry becomes:
drawtext=fontfile=/path/to/font.ttf:text='subtitle text':fontsize=48:fontcolor=white:x=(w-text_w)/2:y=h-th-50:box=1:boxcolor=black@0.5:boxborderw=5:enable='between(t,START_TIME,END_TIME)'
Combine all entries with commas:
ffmpeg -i input.mp4 -vf "drawtext=...,drawtext=...,drawtext=..." -c:a copy output.mp4
Custom subtitle styling:
ffmpeg -i input.mp4 \
-vf "subtitles=subtitle.srt:force_style='FontName=Arial,FontSize=24,PrimaryColour=&H00FFFFFF'" \
-c:a copy output.mp4
3. Extract Audio from Video
Extract audio track in various formats.
Extract as MP3:
ffmpeg -i input.mp4 -vn -c:a libmp3lame -b:a 192k -map 0:a:0 output.mp3
Extract as AAC:
ffmpeg -i input.mp4 -vn -c:a aac -b:a 192k -map 0:a:0 output.aac
Extract as WAV (lossless):
ffmpeg -i input.mp4 -vn -c:a pcm_s16le -map 0:a:0 output.wav
Copy audio without re-encoding:
ffmpeg -i input.mp4 -vn -c:a copy -map 0:a:0 output.m4a
Parameters:
-vn- Remove video stream-c:a- Audio codec (libmp3lame, aac, copy)-b:a- Audio bitrate (128k, 192k, 320k)-map 0:a:0- Select first audio stream
4. Convert Image to Video
Convert static image to video with specified duration.
Basic conversion:
ffmpeg -loop 1 -i image.png \
-c:v libx264 -t 10 -pix_fmt yuv420p \
output.mp4
With silent audio for compatibility:
ffmpeg -loop 1 -i image.png \
-f lavfi -i anullsrc=channel_layout=stereo:sample_rate=44100 \
-c:v libx264 -c:a aac -t 10 -pix_fmt yuv420p -shortest \
output.mp4
Custom dimensions:
ffmpeg -loop 1 -i image.png \
-f lavfi -i anullsrc \
-vf "scale=1920:1080" \
-c:v libx264 -c:a aac -t 10 -pix_fmt yuv420p -shortest \
output.mp4
Parameters:
-loop 1- Loop image input-t- Duration in seconds-pix_fmt yuv420p- Ensure compatibilityanullsrc- Generate silent audio-shortest- Match shortest input duration
5. Merge/Concatenate Videos
Combine multiple videos into one.
Method 1: Concat demuxer (same codec/format):
# Create file list
echo "file 'video1.mp4'" > list.txt
echo "file 'video2.mp4'" >> list.txt
# Concatenate
ffmpeg -f concat -safe 0 -i list.txt -c copy output.mp4
Method 2: Concat filter (different formats):
ffmpeg -i video1.mp4 -i video2.mp4 -i video3.mp4 \
-filter_complex "[0:v][0:a][1:v][1:a][2:v][2:a]concat=n=3:v=1:a=1[outv][outa]" \
-map "[outv]" -map "[outa]" output.mp4
Normalize before merging (different resolutions/framerates):
For each input video, apply normalization:
scale=1920:1080:force_original_aspect_ratio=decrease,
pad=1920:1080:(ow-iw)/2:(oh-ih)/2:color=black,
setsar=1,
fps=30,
setpts=PTS-STARTPTS
For audio:
aformat=sample_fmts=fltp:sample_rates=44100:channel_layouts=stereo,
asetpts=PTS-STARTPTS
Then concatenate normalized streams using concat protocol or concat filter.
Handle videos without audio:
Check if video has audio using ffprobe. If missing, add silent audio:
ffmpeg -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=44100:duration=VIDEO_DURATION
Mix with video stream before normalization.
6. Mix Audio with Video
Combine video with background music or replace audio.
Basic audio mixing:
ffmpeg -i video.mp4 -i music.mp3 \
-filter_complex "[0:a]volume=1.0[a0];[1:a]volume=0.5[a1];[a0][a1]amix=inputs=2:duration=first[a]" \
-map 0:v -map "[a]" -c:v copy output.mp4
Replace video audio:
ffmpeg -i video.mp4 -i new_audio.mp3 \
-map 0:v -map 1:a -c:v copy -c:a aac -shortest output.mp4
Advanced mixing with fade effects:
ffmpeg -i video.mp4 -i music.mp3 \
-filter_complex "
[1:a]afade=t=in:st=0:d=2,afade=t=out:st=28:d=2,volume=0.5[a1];
[0:a]volume=1.0[a0];
[a0][a1]amix=inputs=2:duration=first[a]
" \
-map 0:v -map "[a]" -c:v copy output.mp4
Partial mixing with time control:
Process audio with:
[1:a]atrim=duration=DURATION,asetpts=PTS-STARTPTS,volume=VOLUME,adelay=START_TIME*1000|START_TIME*1000[overlay]
Mix with main audio:
[0:a]volume=VIDEO_VOLUME[main];
[main][overlay]amix=inputs=2:duration=first[out]
Loop short audio:
[1:a]aloop=loop=-1:size=2e9,atrim=duration=VIDEO_DURATION[looped]
Parameters:
volume- Volume multiplier (0.0-2.0)amix:duration- longest/shortest/firstadelay- Delay in millisecondsafade- Fade in/outatrim- Trim audio durationaloop- Loop audio (-1 for infinite)
7. Apply Video Transitions
Apply transition effects between multiple videos (requires FFmpeg 4.3+).
Fade transition:
ffmpeg -i video1.mp4 -i video2.mp4 \
-filter_complex "
[0:v][1:v]xfade=transition=fade:duration=1:offset=5[v];
[0:a][1:a]acrossfade=d=1[a]
" \
-map "[v]" -map "[a]" output.mp4
Multiple videos with transitions:
ffmpeg -i v1.mp4 -i v2.mp4 -i v3.mp4 \
-filter_complex "
[0:v][1:v]xfade=transition=fade:duration=1:offset=5[v01];
[v01][2:v]xfade=transition=wipeleft:duration=1:offset=10[v];
[0:a][1:a]acrossfade=d=1[a01];
[a01][2:a]acrossfade=d=1[a]
" \
-map "[v]" -map "[a]" output.mp4
Available transitions:
fade,fadeblack,fadewhitewipeleft,wiperight,wipeup,wipedownslideleft,slideright,slideup,slidedowncirclecrop,rectcrop,distancedissolve,pixelize,radial
Normalize videos before transition:
When videos have different resolutions or framerates:
[0:v]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black,settb=AVTB[v0];
[1:v]scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black,settb=AVTB[v1];
[v0][v1]xfade=transition=fade:duration=1:offset=5[v]
Fallback for FFmpeg < 4.3:
Use fade + concat instead:
# First video: fade out at end
[0:v]fade=t=out:st=5:d=1[v0];
# Second video: fade in at start
[1:v]fade=t=in:st=0:d=1[v1];
# Concatenate
[v0][0:a][v1][1:a]concat=n=2:v=1:a=1[outv][outa]
Parameters:
transition- Transition typeduration- Transition duration in secondsoffset- When transition starts in first videoacrossfade:d- Audio crossfade duration
8. Overlay Video/Image
Place one video or image on top of another.
Basic overlay (logo/watermark):
ffmpeg -i video.mp4 -i logo.png \
-filter_complex "[1:v]scale=150:-1[logo];[0:v][logo]overlay=10:10" \
-c:a copy output.mp4
Positioned overlays:
# Bottom-right corner
overlay=main_w-overlay_w-10:main_h-overlay_h-10
# Center
overlay=(main_w-overlay_w)/2:(main_h-overlay_h)/2
# Top-right
overlay=main_w-overlay_w-10:10
Overlay with opacity:
ffmpeg -i video.mp4 -i logo.png \
-filter_complex "[1:v]scale=150:-1,colorchannelmixer=aa=0.5[logo];[0:v][logo]overlay=10:10" \
-c:a copy output.mp4
Timed overlay (show from 5 to 15 seconds):
ffmpeg -i video.mp4 -i logo.png \
-filter_complex "[1:v]scale=150:-1[logo];[0:v][logo]overlay=10:10:enable='between(t,5,15)'" \
-c:a copy output.mp4
Picture-in-picture:
ffmpeg -i main.mp4 -i small.mp4 \
-filter_complex "
[1:v]scale=320:-1[pip];
[0:v][pip]overlay=main_w-overlay_w-10:10[v]
" \
-map "[v]" -map 0:a -c:a copy output.mp4
Audio handling options:
# Use main video audio only
-map 0:a
# Use overlay video audio only
-map 1:a
# Mix both audio tracks
-filter_complex "...[v];[0:a]volume=1.0[a0];[1:a]volume=0.5[a1];[a0][a1]amix=inputs=2:duration=longest[a]"
-map "[v]" -map "[a]"
Parameters:
scale- Resize overlay (width:height, -1 for auto)colorchannelmixer=aa- Opacity (0.0-1.0)overlay=x:y- Positionenable- Time controleof_action=pass- Continue main after overlay ends
9. Separate Video and Audio
Split video into separate video (muted) and audio files.
Create muted video:
ffmpeg -i input.mp4 -an -c:v copy video_only.mp4
Extract audio:
ffmpeg -i input.mp4 -vn -c:a libmp3lame -b:a 192k -map 0:a:0 audio.mp3
Both in one operation:
# Muted video
ffmpeg -i input.mp4 -an -c:v copy video_only.mp4
# Audio file
ffmpeg -i input.mp4 -vn -c:a libmp3lame -b:a 192k -map 0:a:0 audio.mp3
Parameters:
-an- Remove audio stream-vn- Remove video stream-c:v copy- Copy video without re-encoding-c:a- Audio codec (libmp3lame, aac, copy)
10. Apply Fade In/Out
Add fade in or fade out effects to video and/or audio.
Video fade in/out:
ffmpeg -i input.mp4 \
-vf "fade=type=in:st=0:d=2,fade=type=out:st=28:d=2" \
-c:a copy output.mp4
Audio fade in/out:
ffmpeg -i input.mp4 \
-af "afade=type=in:st=0:d=2,afade=type=out:st=28:d=2" \
-c:v copy output.mp4
Both video and audio fade:
ffmpeg -i input.mp4 \
-vf "fade=type=in:st=0:d=2,fade=type=out:st=28:d=2" \
-af "afade=type=in:st=0:d=2,afade=type=out:st=28:d=2" \
output.mp4
Fade to/from white:
ffmpeg -i input.mp4 \
-vf "fade=type=in:st=0:d=2:color=white" \
-c:a copy output.mp4
Parameters:
type-inoroutst- Start time in secondsd- Duration in secondscolor- Fade color (default: black)
11. Add Image Stamp/Watermark
Add logo, watermark, or stamp image to video.
Basic stamp:
ffmpeg -i video.mp4 -i stamp.png \
-filter_complex "[1:v]scale=150:-1[stamp];[0:v][stamp]overlay=10:10" \
-c:a copy output.mp4
Rotated stamp:
ffmpeg -i video.mp4 -i stamp.png \
-filter_complex "
[1:v]scale=150:-1,rotate=PI/4:fillcolor=none[stamp];
[0:v][stamp]overlay=10:10
" \
-c:a copy output.mp4
Stamp with opacity:
ffmpeg -i video.mp4 -i stamp.png \
-filter_complex "
[1:v]scale=150:-1,colorchannelmixer=aa=0.5[stamp];
[0:v][stamp]overlay=10:10
" \
-c:a copy output.mp4
Timed stamp (show from 5 to 15 seconds):
ffmpeg -i video.mp4 -i stamp.png \
-filter_complex "
[1:v]scale=150:-1[stamp];
[0:v][stamp]overlay=10:10:enable='between(t,5,15)'
" \
-c:a copy output.mp4
Parameters:
scale- Resize stamp (width:height, -1 for auto)rotate- Rotation angle in radians (PI/2 = 90°, PI/4 = 45°)colorchannelmixer=aa- Opacity (0.0-1.0)overlay=x:y- Positionenable- Time control
12. Trim/Cut Video
Extract portion of video between specified times.
Fast cut (keyframe-accurate, input seeking):
ffmpeg -ss 5 -i input.mp4 -t 10 -c copy output.mp4
Accurate cut (frame-exact, output seeking + re-encode):
ffmpeg -i input.mp4 -ss 5 -t 10 -c:v libx264 -c:a aac output.mp4
Combined seeking (fast + accurate):
ffmpeg -ss 4 -i input.mp4 -ss 1 -t 10 -c:v libx264 -c:a aac output.mp4
Extract from 5 to 15 seconds:
ffmpeg -ss 5 -i input.mp4 -to 10 -c copy output.mp4
Time duration formats:
-ss 01:23:45.678 # HH:MM:SS.mmm
-ss 5:30 # MM:SS (5 min 30 sec)
-ss 90 # seconds (numeric)
-ss 5500ms # milliseconds with suffix
Parameters:
-ssbefore-i- Input seeking (fast, keyframe-accurate)-ssafter-i- Output seeking (slow, frame-accurate)-to- End time (absolute when-ssis after-i, relative when before)-t- Duration (always relative from seek point)-c copy- Stream copy (fast, keyframe-accurate only)-c:v libx264- Re-encode for frame-accurate cutting
Gotcha:
-tobehaves differently depending on-ssposition. With input seeking (-ssbefore-i),-tobecomes relative to the new start.
13. Probe Media Information
Query metadata and technical details of media files.
Complete metadata (JSON):
ffprobe -v quiet -print_format json -show_format -show_streams input.mp4
Quick info:
ffmpeg -i input.mp4 2>&1 | grep -E 'Duration|Stream'
Video resolution:
ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=s=x:p=0 input.mp4
Video duration:
ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 input.mp4
Check if video has audio:
ffprobe -i input.mp4 -show_streams -select_streams a -loglevel error
Framerate:
ffprobe -v error -select_streams v:0 -show_entries stream=r_frame_rate -of default=noprint_wrappers=1:nokey=1 input.mp4
Codec information:
ffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of default=noprint_wrappers=1:nokey=1 input.mp4
Advanced Patterns
Complex Filter Graphs
Multiple outputs from single input:
ffmpeg -i input.mp4 \
-filter_complex "
[0:v]split=2[v1][v2];
[v1]scale=1920:1080[out1];
[v2]scale=1280:720[out2]
" \
-map "[out1]" -c:v libx264 output_1080p.mp4 \
-map "[out2]" -c:v libx264 output_720p.mp4
Side-by-side comparison:
ffmpeg -i left.mp4 -i right.mp4 \
-filter_complex "
[0:v]scale=640:480[left];
[1:v]scale=640:480[right];
[left][right]hstack[v]
" \
-map "[v]" output.mp4
Quality Control
CRF (Constant Rate Factor) — recommended for local files:
| CRF | Quality | Use Case |
|---|---|---|
| 0 | Lossless | Archival |
| 18 | Visually lossless | Professional editing |
| 23 | Good (default) | General purpose |
| 28 | Acceptable | Web distribution |
| 51 | Worst | (not recommended) |
ffmpeg -i input.mp4 -c:v libx264 -crf 23 -preset medium -c:a aac output.mp4
Constrained bitrate — recommended for streaming:
# Average bitrate with buffer control
ffmpeg -i input.mp4 -c:v libx264 -b:v 2M -maxrate 2.5M -bufsize 5M -c:a aac output.mp4
Gotcha:
-b:v 2M= 2 Megabits/s (not bytes). FFmpeg uses bits/s. UseK,M,Gsuffixes.
Two-pass encoding (best quality at target bitrate):
# Pass 1 (analysis only — output to /dev/null)
ffmpeg -i input.mp4 -c:v libx264 -b:v 2M -pass 1 -f null /dev/null
# Pass 2 (actual encoding using analysis)
ffmpeg -i input.mp4 -c:v libx264 -b:v 2M -pass 2 -c:a aac output.mp4
Encoding presets (speed → quality tradeoff):
ultrafast > superfast > veryfast > faster > fast > medium > slow > slower > veryslow
Tunes (content-type optimization):
# Animation
ffmpeg -i input.mp4 -c:v libx264 -crf 20 -tune animation output.mp4
# Screen recording
ffmpeg -i input.mp4 -c:v libx264 -crf 18 -tune stillimage output.mp4
# Streaming (low latency)
ffmpeg -i input.mp4 -c:v libx264 -preset fast -tune zerolatency output.mp4
Audio codec options:
# AAC at 192kbps
-c:a aac -b:a 192k
# MP3 VBR high quality (~190kbps average)
-c:a libmp3lame -q:a 2
# MP3 CBR 192kbps
-c:a libmp3lame -b:a 192k
Gotcha: VBR (
-q:a) and CBR (-b:a) are mutually exclusive for MP3. Don't use both.
Hardware Acceleration
macOS (VideoToolbox):
ffmpeg -hwaccel videotoolbox -i input.mp4 -c:v h264_videotoolbox output.mp4
Linux/NVIDIA (NVENC):
ffmpeg -hwaccel cuda -i input.mp4 -c:v h264_nvenc output.mp4
Auto-detect:
ffmpeg -hwaccel auto -i input.mp4 -c:v libx264 output.mp4
Common Issues and Solutions
Fix Corrupted Video
ffmpeg -i corrupted.mp4 -c copy fixed.mp4
Add Silent Audio to Video
ffmpeg -i video.mp4 -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=44100 \
-c:v copy -c:a aac -shortest output.mp4
Ensure Even Dimensions (H.264 requirement)
ffmpeg -i input.mp4 -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" -c:a copy output.mp4
Convert Variable to Constant Framerate
ffmpeg -i input.mp4 -vf fps=30 -c:v libx264 -c:a copy output.mp4
Rotate Video
# 90° clockwise
ffmpeg -i input.mp4 -vf "transpose=1" -c:a copy output.mp4
# 90° counter-clockwise
ffmpeg -i input.mp4 -vf "transpose=2" -c:a copy output.mp4
# 180°
ffmpeg -i input.mp4 -vf "transpose=2,transpose=2" -c:a copy output.mp4
Remove Metadata
ffmpeg -i input.mp4 -map_metadata -1 -c copy output.mp4
Best Practices
- Test with short clips first before processing long videos
- Use
-c copywhen possible to avoid re-encoding (faster, lossless) - Always specify codecs explicitly to avoid unexpected defaults
- Ensure even dimensions for H.264:
scale=trunc(iw/2)*2:trunc(ih/2)*2 - Add
-pix_fmt yuv420pfor maximum compatibility - Use CRF (18-28) for quality control instead of fixed bitrate
- Check FFmpeg version for filter compatibility:
ffmpeg -version - Backup original files before batch processing
- Use
-yflag cautiously (overwrites without confirmation) - Normalize audio when mixing from different sources
Common Global Options
-y- Overwrite output file without asking-n- Never overwrite output file-v quiet- Suppress output messages-stats- Show encoding statistics-threads 0- Use all CPU cores
Reference Documentation
Official Syntax Reference
For authoritative FFmpeg syntax rules extracted from official documentation (ffmpeg.org), consult:
references/ffmpeg-syntax-reference.md
This includes:
- CLI grammar and option ordering rules
- Stream specifier syntax (all patterns)
- Stream mapping and auto-selection behavior
- Seeking behavior (input vs output seeking)
- Time duration, color, size, expression syntax
- Codec options with valid ranges (libx264, AAC, libmp3lame)
- Format options (concat demuxer, probing)
- Critical gotchas and common mistakes
Detailed Filter Reference
For comprehensive documentation on all FFmpeg filters, parameters, and advanced usage patterns, consult:
references/ffmpeg-filters.md
This includes:
- Video filters: drawtext, fade, xfade, scale, overlay, pad, rotate, etc.
- Audio filters: afade, amix, acrossfade, volume, aformat, etc.
- Filter graph syntax hierarchy and escaping rules
- Expression evaluation (variables, functions, constants)
- Performance tips and common pitfalls
- Version compatibility information
Common Recipes and Patterns
For frequently used command patterns and real-world examples, consult:
references/common-recipes.md
This includes:
- Text and subtitles recipes
- Audio processing workflows
- Video editing patterns
- Format conversion examples
- Quality optimization techniques
- Troubleshooting solutions
- Batch processing scripts
Access references when:
- Need accurate syntax rules →
ffmpeg-syntax-reference.md - Need filter parameters or escaping rules →
ffmpeg-filters.md - Need real-world command examples →
common-recipes.md
Version Requirements
- FFmpeg 4.3+ - Required for xfade transitions
- FFmpeg 3.0+ - Most other filters
- Check version:
ffmpeg -version - Check filter availability:
ffmpeg -filters | grep filter_name
Output Format Compatibility
Ensure H.264/AAC compatibility:
-c:v libx264 -c:a aac -pix_fmt yuv420p -movflags +faststart
Parameters:
-pix_fmt yuv420p- Maximum playback compatibility-movflags +faststart- Enable web streaming (MP4)- Even dimensions required for H.264