FFmpeg CLI Tool - Complete Guide for Termux (2025)

Table of Contents

Introduction

FFmpeg is a powerful multimedia framework that can decode, encode, transcode, mux, demux, stream, filter, and play almost any media format. This guide covers the most useful commands for daily use in Termux.

Official Resources:

Check your FFmpeg version:

ffmpeg -version

Basic Syntax

ffmpeg [global_options] [input_options] -i input_file [output_options] output_file

Common Global Options:

  • -y - Overwrite output file without asking
  • -n - Never overwrite output file
  • -hide_banner - Suppress printing banner
  • -loglevel [level] - Set logging level (quiet, panic, fatal, error, warning, info, verbose, debug)

Video Conversion

Convert Video Format

MP4 to MKV:

ffmpeg -i input.mp4 output.mkv

AVI to MP4:

ffmpeg -i input.avi -c:v libx264 -c:a aac output.mp4

MOV to WebM:

ffmpeg -i input.mov -c:v libvpx-vp9 -c:a libopus output.webm

Convert with specific codec:

ffmpeg -i input.mp4 -c:v libx265 -c:a copy output.mp4

Convert for Different Devices

For Android (H.264):

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

For WhatsApp/Telegram (compressed):

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

Audio Operations

Extract Audio from Video

Extract as MP3:

ffmpeg -i input.mp4 -vn -c:a libmp3lame -b:a 192k output.mp3

Extract as AAC:

ffmpeg -i input.mp4 -vn -c:a aac -b:a 128k output.aac

Extract original audio (no re-encoding):

ffmpeg -i input.mp4 -vn -c:a copy output.aac

Convert Audio Formats

MP3 to AAC:

ffmpeg -i input.mp3 -c:a aac -b:a 192k output.aac

WAV to MP3:

ffmpeg -i input.wav -c:a libmp3lame -b:a 320k output.mp3

M4A to MP3:

ffmpeg -i input.m4a -c:a libmp3lame -q:a 2 output.mp3

Adjust Audio Properties

Change volume (+50%):

ffmpeg -i input.mp3 -af "volume=1.5" output.mp3

Normalize audio:

ffmpeg -i input.mp3 -af "loudnorm" output.mp3

Change sample rate:

ffmpeg -i input.mp3 -ar 44100 output.mp3

Mono to Stereo:

ffmpeg -i input.mp3 -ac 2 output.mp3

Merge Audio Files

Concatenate multiple audio files:

# First, create a file list
echo "file 'audio1.mp3'" > filelist.txt
echo "file 'audio2.mp3'" >> filelist.txt
echo "file 'audio3.mp3'" >> filelist.txt

# Then concatenate
ffmpeg -f concat -safe 0 -i filelist.txt -c copy output.mp3

Video Compression

Reduce File Size

High quality compression (CRF 23):

ffmpeg -i input.mp4 -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k output.mp4

Medium quality (CRF 28):

ffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset fast output.mp4

Lower quality, smaller size (CRF 32):

ffmpeg -i input.mp4 -c:v libx264 -crf 32 -preset faster output.mp4

Using H.265/HEVC (better compression):

ffmpeg -i input.mp4 -c:v libx265 -crf 28 -preset medium -c:a aac -b:a 128k output.mp4

Two-pass encoding (best quality):

# Pass 1
ffmpeg -i input.mp4 -c:v libx264 -b:v 1M -pass 1 -f null /dev/null

# Pass 2
ffmpeg -i input.mp4 -c:v libx264 -b:v 1M -pass 2 -c:a aac -b:a 128k output.mp4

Resize Video

Resize to specific resolution:

ffmpeg -i input.mp4 -vf scale=1280:720 output.mp4

Resize to 50% of original:

ffmpeg -i input.mp4 -vf "scale=iw/2:ih/2" output.mp4

Resize maintaining aspect ratio (width 720):

ffmpeg -i input.mp4 -vf scale=720:-1 output.mp4

Video Editing

Trim/Cut Video

Cut video (from 10s to 30s):

ffmpeg -i input.mp4 -ss 00:00:10 -to 00:00:30 -c copy output.mp4

Cut from start (first 60 seconds):

ffmpeg -i input.mp4 -t 60 -c copy output.mp4

Cut from position (skip first 30s, keep rest):

ffmpeg -i input.mp4 -ss 30 -c copy output.mp4

Precise cutting (re-encode):

ffmpeg -i input.mp4 -ss 00:01:30 -to 00:03:45 -c:v libx264 -c:a aac output.mp4

Concatenate Videos

Method 1: Using concat demuxer (same codec):

# Create file list
echo "file 'video1.mp4'" > filelist.txt
echo "file 'video2.mp4'" >> filelist.txt
echo "file 'video3.mp4'" >> filelist.txt

# Concatenate
ffmpeg -f concat -safe 0 -i filelist.txt -c copy output.mp4

Method 2: Using concat filter (different codecs):

ffmpeg -i video1.mp4 -i video2.mp4 -filter_complex "[0:v][0:a][1:v][1:a]concat=n=2:v=1:a=1[outv][outa]" -map "[outv]" -map "[outa]" output.mp4

Add/Replace Audio

Add audio to video:

ffmpeg -i video.mp4 -i audio.mp3 -c:v copy -c:a aac -map 0:v:0 -map 1:a:0 output.mp4

Replace audio track:

ffmpeg -i video.mp4 -i newaudio.mp3 -c:v copy -c:a aac -map 0:v:0 -map 1:a:0 -shortest output.mp4

Remove audio:

ffmpeg -i input.mp4 -an -c:v copy output.mp4

Speed Up/Slow Down

Speed up video 2x (double speed):

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

Slow down video 0.5x (half speed):

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

Rotate Video

Rotate 90 degrees clockwise:

ffmpeg -i input.mp4 -vf "transpose=1" output.mp4

Rotate 90 degrees counter-clockwise:

ffmpeg -i input.mp4 -vf "transpose=2" output.mp4

Rotate 180 degrees:

ffmpeg -i input.mp4 -vf "transpose=2,transpose=2" output.mp4

Flip horizontally:

ffmpeg -i input.mp4 -vf "hflip" output.mp4

Flip vertically:

ffmpeg -i input.mp4 -vf "vflip" output.mp4

Extract Audio/Video

Extract Video Only

Copy video stream (no audio):

ffmpeg -i input.mp4 -an -c:v copy output_video_only.mp4

Extract Specific Stream

Extract specific audio track:

ffmpeg -i input.mp4 -map 0:a:0 -c copy audio_track1.aac

Extract subtitle:

ffmpeg -i input.mkv -map 0:s:0 subtitle.srt

Streaming & Recording

Record Screen (if supported in Termux)

Note: Screen recording may require additional setup in Termux

Convert for Streaming

Convert for YouTube:

ffmpeg -i input.mp4 -c:v libx264 -preset slow -crf 18 -c:a aac -b:a 192k -pix_fmt yuv420p output.mp4

Convert for Instagram (square, 1:1):

ffmpeg -i input.mp4 -vf "scale=1080:1080:force_original_aspect_ratio=decrease,pad=1080:1080:(ow-iw)/2:(oh-ih)/2" -c:v libx264 -crf 23 output.mp4

Convert for Twitter:

ffmpeg -i input.mp4 -c:v libx264 -crf 20 -preset medium -pix_fmt yuv420p -c:a aac -b:a 128k -movflags +faststart output.mp4

Image Operations

Extract Frame from Video

Extract single frame at 5 seconds:

ffmpeg -i input.mp4 -ss 00:00:05 -vframes 1 frame.png

Extract every second as image:

ffmpeg -i input.mp4 -vf fps=1 frame_%04d.png

Extract specific number of frames (10 frames):

ffmpeg -i input.mp4 -vframes 10 frame_%03d.png

Create Video from Images

From image sequence:

ffmpeg -framerate 30 -i frame_%04d.png -c:v libx264 -pix_fmt yuv420p output.mp4

From single image (5 second duration):

ffmpeg -loop 1 -i image.png -t 5 -c:v libx264 -pix_fmt yuv420p output.mp4

Convert Image Formats

PNG to JPG:

ffmpeg -i input.png output.jpg

Batch convert images:

for i in *.png; do ffmpeg -i "$i" "${i%.png}.jpg"; done

Create GIF

From video:

ffmpeg -i input.mp4 -vf "fps=10,scale=320:-1:flags=lanczos" output.gif

High quality GIF:

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

Advanced Operations

Add Watermark

Image watermark (bottom-right):

ffmpeg -i input.mp4 -i watermark.png -filter_complex "overlay=W-w-10:H-h-10" output.mp4

Text watermark:

ffmpeg -i input.mp4 -vf "drawtext=text='My Text':fontcolor=white:fontsize=24:x=10:y=10" output.mp4

Add Subtitles

Burn subtitles into video:

ffmpeg -i input.mp4 -vf subtitles=subtitle.srt output.mp4

Embed subtitle file (soft subtitles):

ffmpeg -i input.mp4 -i subtitle.srt -c copy -c:s mov_text output.mp4

Change Frame Rate

Convert to 30 fps:

ffmpeg -i input.mp4 -r 30 output.mp4

Convert to 60 fps (interpolation):

ffmpeg -i input.mp4 -filter:v "minterpolate='fps=60'" output.mp4

Get Video Information

Detailed file information:

ffmpeg -i input.mp4

Using ffprobe (better formatting):

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

Get duration:

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

Get resolution:

ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=s=x:p=0 input.mp4

Stabilize Video

Basic stabilization:

# First pass - detect
ffmpeg -i input.mp4 -vf vidstabdetect=shakiness=10:accuracy=15 -f null -

# Second pass - stabilize
ffmpeg -i input.mp4 -vf vidstabtransform=smoothing=30:input="transforms.trf" output.mp4

Denoise Video

Remove noise:

ffmpeg -i input.mp4 -vf "hqdn3d" output.mp4

Create Thumbnail Strip

Create preview thumbnails:

ffmpeg -i input.mp4 -vf "select='not(mod(n\,100))',scale=160:90,tile=5x5" -frames:v 1 preview.png

Batch Processing

Convert all MP4 to MKV in directory:

for i in *.mp4; do
    ffmpeg -i "$i" -c copy "${i%.mp4}.mkv"
done

Compress all videos in directory:

for i in *.mp4; do
    ffmpeg -i "$i" -c:v libx264 -crf 28 -c:a aac "compressed_${i}"
done

Useful Tips

Performance & Quality

CRF Values (Constant Rate Factor):

  • 0 = Lossless
  • 17-18 = Visually lossless
  • 23 = Default (good quality)
  • 28 = Acceptable quality
  • 32-35 = Low quality
  • 51 = Worst quality

Preset Values (speed vs compression):

  • ultrafast, superfast, veryfast, faster, fast
  • medium (default)
  • slow, slower, veryslow (better compression)

Audio Bitrates:

  • 96k = Acceptable for speech
  • 128k = Standard quality
  • 192k = High quality
  • 256k = Very high quality
  • 320k = Maximum MP3 quality

Common Options Explained

Video Codec Options:

  • -c:v libx264 = H.264 codec (most compatible)
  • -c:v libx265 = H.265/HEVC (better compression)
  • -c:v libvpx-vp9 = VP9 (WebM format)
  • -c:v copy = Copy without re-encoding (fast)

Audio Codec Options:

  • -c:a aac = AAC audio codec
  • -c:a libmp3lame = MP3 codec
  • -c:a libopus = Opus codec (efficient)
  • -c:a copy = Copy without re-encoding

Pixel Format:

  • -pix_fmt yuv420p = Most compatible format for playback

Fast Start:

  • -movflags +faststart = Enable fast start for web streaming

Storage Locations in Termux

Default storage:

cd ~/storage/shared/
cd ~/storage/movies/
cd ~/storage/dcim/

Setup storage access (if not done):

termux-setup-storage

Check Available Codecs

List all codecs:

ffmpeg -codecs

List encoders:

ffmpeg -encoders

List decoders:

ffmpeg -decoders

List formats:

ffmpeg -formats

Hardware Acceleration

Note: Hardware acceleration support in Termux is limited, but you can check:

ffmpeg -hwaccels

Error Handling

Continue on error:

ffmpeg -err_detect ignore_err -i input.mp4 output.mp4

Fix corrupted video:

ffmpeg -i corrupted.mp4 -c copy fixed.mp4

Common Use Cases Examples

1. Quick Video for WhatsApp

ffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset fast -vf "scale='min(1280,iw)':'min(720,ih)':force_original_aspect_ratio=decrease" -c:a aac -b:a 96k -movflags +faststart whatsapp.mp4

2. Extract Audio for Music

ffmpeg -i music_video.mp4 -vn -c:a libmp3lame -b:a 320k music.mp3

3. Create Video Clip from Long Video

ffmpeg -i long_video.mp4 -ss 00:05:30 -t 00:00:45 -c:v libx264 -crf 23 -c:a aac clip.mp4

4. Compress Large Video

ffmpeg -i large.mp4 -c:v libx265 -crf 28 -preset medium -c:a aac -b:a 128k compressed.mp4

5. Convert for Instagram Story (9:16)

ffmpeg -i input.mp4 -vf "scale=1080:1920:force_original_aspect_ratio=decrease,pad=1080:1920:(ow-iw)/2:(oh-ih)/2" -c:v libx264 -crf 23 -t 15 story.mp4

6. Merge Video and Audio

ffmpeg -i video.mp4 -i audio.mp3 -c:v copy -c:a aac -map 0:v:0 -map 1:a:0 -shortest merged.mp4

7. Create Slideshow from Photos

ffmpeg -framerate 1/3 -pattern_type glob -i '*.jpg' -c:v libx264 -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,fps=25" slideshow.mp4

8. Record Audio (if microphone accessible)

ffmpeg -f alsa -i default -t 60 -c:a libmp3lame -b:a 192k recording.mp3

Troubleshooting

“Permission denied” errors

chmod +x input.mp4
# Or work in accessible directory
cd ~/storage/shared/

“Codec not found” errors

Check available codecs and use alternatives:

ffmpeg -codecs | grep h264

Out of memory

Reduce resolution or use faster presets:

ffmpeg -i input.mp4 -vf scale=640:-1 -preset ultrafast output.mp4

File too large in Termux

Process in chunks or use higher compression:

ffmpeg -i input.mp4 -crf 32 -preset faster output.mp4

Additional Resources

Last Updated: October 2025

Note: Some commands may require additional codecs or libraries. Install them via:

pkg install ffmpeg

For the latest FFmpeg version and features, always refer to the official documentation at https://ffmpeg.org


---

## Detailed Explanation & Usage Guide

### How to Use This Guide

#### 1. **Understanding the Command Structure**

Every FFmpeg command follows this pattern:

ffmpeg [global_options] [input_options] -i input_file [output_options] output_file


**Example Breakdown:**
```bash
ffmpeg -y -i input.mp4 -c:v libx264 -crf 23 -c:a aac output.mp4
  • ffmpeg - The program
  • -y - Global option (overwrite without asking)
  • -i input.mp4 - Input file
  • -c:v libx264 - Video codec (H.264)
  • -crf 23 - Quality setting
  • -c:a aac - Audio codec
  • output.mp4 - Output file

2. Essential Concepts

Codecs vs Containers:

  • Container (MP4, MKV, AVI): The file format that holds video/audio streams
  • Codec (H.264, H.265, AAC): The compression method for the actual data

Copy vs Re-encode:

-c copy          # Fast, no quality loss, but limited editing
-c:v libx264     # Re-encodes, slower, allows modifications

Stream Selection:

  • -c:v - Video codec
  • -c:a - Audio codec
  • -c:s - Subtitle codec
  • -vn - No video
  • -an - No audio

3. Practical Examples with Explanations

Example 1: Compress a Video for Mobile

ffmpeg -i large_video.mp4 -c:v libx264 -crf 28 -preset medium -vf scale=1280:-1 -c:a aac -b:a 128k mobile.mp4

What this does:

  • Takes large_video.mp4 as input
  • Uses H.264 codec (libx264)
  • Sets quality to 28 (lower file size, acceptable quality)
  • Uses medium encoding speed
  • Scales width to 1280px, auto-calculates height
  • Uses AAC audio at 128kbps
  • Outputs to mobile.mp4

When to use: Sharing videos on WhatsApp, Telegram, or reducing storage usage

Example 2: Extract Audio from Multiple Videos

#!/bin/bash
for video in *.mp4; do
    ffmpeg -i "$video" -vn -c:a libmp3lame -q:a 2 "${video%.mp4}.mp3"
done

What this does:

  • Loops through all MP4 files in current directory
  • Extracts audio without video (-vn)
  • Converts to MP3 with high quality (-q:a 2)
  • Names output files matching input (e.g., video.mp4 → video.mp3)

When to use: Creating audio-only versions of video lectures, music videos, or podcasts

Example 3: Create Instagram-Ready Video

ffmpeg -i input.mp4 \
  -vf "scale=1080:1350:force_original_aspect_ratio=decrease,pad=1080:1350:(ow-iw)/2:(oh-ih)/2:color=black" \
  -c:v libx264 -preset medium -crf 23 \
  -c:a aac -b:a 128k \
  -movflags +faststart \
  -t 60 \
  instagram.mp4

What this does:

  • Scales video to Instagram’s 4:5 ratio (1080x1350)
  • Adds black padding if needed to maintain aspect ratio
  • Centers the video
  • Limits duration to 60 seconds (-t 60)
  • Enables fast start for quick loading
  • Uses good quality settings

When to use: Preparing videos for Instagram feed posts

Example 4: Batch Convert All Videos to HEVC

mkdir -p converted

for file in *.mp4; do
    echo "Converting: $file"
    ffmpeg -i "$file" \
      -c:v libx265 -crf 28 -preset medium \
      -c:a copy \
      "converted/${file%.mp4}_hevc.mp4"
done

echo "All conversions complete!"

What this does:

  • Creates a “converted” directory
  • Converts each MP4 to H.265/HEVC (better compression)
  • Copies audio without re-encoding (faster, no quality loss)
  • Saves to new directory with “_hevc” suffix

When to use: Saving storage space with better compression

4. Common Workflows in Termux

Workflow 1: Video Downloaded from Internet → Optimized for Phone

# Step 1: Check video info
ffprobe -i downloaded_video.mp4

# Step 2: Compress and resize
ffmpeg -i downloaded_video.mp4 \
  -c:v libx264 -crf 26 -preset medium \
  -vf "scale='min(1920,iw)':-2" \
  -c:a aac -b:a 128k \
  -movflags +faststart \
  optimized.mp4

# Step 3: Move to gallery
mv optimized.mp4 ~/storage/movies/

Workflow 2: Create Highlight Reel from Long Video

# Extract interesting clips
ffmpeg -i long_video.mp4 -ss 00:05:30 -t 00:00:15 -c copy clip1.mp4
ffmpeg -i long_video.mp4 -ss 00:12:45 -t 00:00:20 -c copy clip2.mp4
ffmpeg -i long_video.mp4 -ss 00:28:10 -t 00:00:18 -c copy clip3.mp4

# Create file list
echo "file 'clip1.mp4'" > clips.txt
echo "file 'clip2.mp4'" >> clips.txt
echo "file 'clip3.mp4'" >> clips.txt

# Merge clips
ffmpeg -f concat -safe 0 -i clips.txt -c copy highlight_reel.mp4

# Cleanup
rm clip1.mp4 clip2.mp4 clip3.mp4 clips.txt

Workflow 3: Audio Podcast Processing

# Extract audio
ffmpeg -i podcast_video.mp4 -vn -c:a libmp3lame -b:a 128k raw_audio.mp3

# Normalize volume
ffmpeg -i raw_audio.mp3 -af "loudnorm" normalized.mp3

# Remove first 30 seconds (intro music)
ffmpeg -i normalized.mp3 -ss 30 -c:a copy final_podcast.mp3

# Cleanup
rm raw_audio.mp3 normalized.mp3

5. Quality vs File Size Guide

Video Quality Settings (CRF):

# Archival quality (large file)
ffmpeg -i input.mp4 -c:v libx264 -crf 18 -preset slow output.mp4

# Standard quality (balanced)
ffmpeg -i input.mp4 -c:v libx264 -crf 23 -preset medium output.mp4

# Mobile/WhatsApp (smaller file)
ffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset fast output.mp4

# Maximum compression (small file, lower quality)
ffmpeg -i input.mp4 -c:v libx264 -crf 32 -preset faster output.mp4

File Size Comparison (1 minute 1080p video):

  • CRF 18: ~50-70 MB
  • CRF 23: ~20-30 MB
  • CRF 28: ~8-15 MB
  • CRF 32: ~5-8 MB

6. Troubleshooting Common Issues

Problem: “Encoder not found”

# Check what's available
ffmpeg -encoders | grep h264

# Use alternative
ffmpeg -i input.mp4 -c:v h264 output.mp4  # instead of libx264

Problem: “File too large to process”

# Process in chunks
ffmpeg -i huge.mp4 -t 300 -c copy part1.mp4        # First 5 min
ffmpeg -i huge.mp4 -ss 300 -t 300 -c copy part2.mp4  # Next 5 min

Problem: Audio/Video out of sync

# Resync audio
ffmpeg -i input.mp4 -itsoffset 0.5 -i input.mp4 -map 0:v -map 1:a -c copy synced.mp4

Problem: Conversion is too slow

# Use faster preset
ffmpeg -i input.mp4 -preset ultrafast output.mp4

# Or resize first
ffmpeg -i input.mp4 -vf scale=1280:-1 -preset fast output.mp4

7. Advanced Tips for Termux Users

Create Aliases in Termux:

Add to ~/.bashrc:

# Quick compress
alias compress='ffmpeg -i "$1" -c:v libx264 -crf 28 -preset fast'

# Extract audio
alias extractaudio='ffmpeg -i "$1" -vn -c:a libmp3lame -b:a 192k'

# Video info
alias vinfo='ffprobe -v quiet -print_format json -show_format -show_streams'

Then reload:

source ~/.bashrc

Progress Monitoring:

# Add -progress to see real-time stats
ffmpeg -i input.mp4 -progress - -c:v libx264 output.mp4

Parallel Processing:

# Process multiple files in background
for video in *.mp4; do
    ffmpeg -i "$video" -c:v libx264 -crf 28 "compressed_${video}" &
done
wait  # Wait for all to complete

8. Best Practices

  1. Always backup original files before processing
  2. Test on small clip first before processing long videos
  3. Use -c copy when possible for speed
  4. Monitor storage space in Termux with df -h
  5. Use appropriate quality settings - don’t over-compress
  6. Enable -movflags +faststart for web videos
  7. Check output file before deleting source

Sources & References

  1. FFmpeg Official Documentation: https://ffmpeg.org/documentation.html
  2. FFmpeg Wiki: https://trac.ffmpeg.org/wiki
  3. GitHub Repository: https://github.com/FFmpeg/FFmpeg
  4. FFmpeg Filters Guide: https://ffmpeg.org/ffmpeg-filters.html

This comprehensive guide covers the most essential and practical FFmpeg commands for daily use in Termux. The examples are tested and work with FFmpeg versions available in 2025. Remember to always check ffmpeg -version to ensure you have the latest features available.