Client
A startup building a modern video editing mobile application targeting creators, influencers, and social media users. They wanted real-time editing, fast exports, and advanced effects all without relying on cloud servers.
Project Overview
The startup needed a powerful, offline, mobile-first video processing engine that works on a wide range of Android devices. Existing solutions or third-party SDKs:
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Were slow
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Lacked advanced filters
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Didn’t support required codecs
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Had licensing limitations
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Were too large in APK size
To meet their requirements, we built a custom high-performance video engine using a self-compiled native FFmpeg library (.so files) optimized specifically for Android.
The engine supports:
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Video trimming
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Merging
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Transcoding
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Audio mixing
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Filters & LUTs
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Watermarking
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Resolution changes
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Format conversion
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Frame extraction
🧩 Key Challenges
1. FFmpeg Is Not Natively Optimized for Android
Stock builds are too heavy and slow. We needed custom compilation with:
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Only necessary codecs
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Hardware acceleration
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ABI-specific optimization
2. APK Size Limitations
Bundling FFmpeg with full codecs would make the app extremely large.
3. Device Compatibility Issues
Android devices differ greatly:
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armv7
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arm64
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x86 (optional)
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Different GPU/CPU architectures
Video processing had to work consistently across all.
4. High Processing Load
Video editing requires:
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Fast decode/encode
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Stable memory usage
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Zero crashes during export
🔧 Our Solution
1. Custom FFmpeg Compilation for Android (NDK Build)
We compiled FFmpeg from source using:
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Android NDK
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Custom shell scripts
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ABI-based builds: arm64-v8a, armeabi-v7a, x86_64 (if required)
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Stripped unused codecs to reduce size
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Enabled essential formats:
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H.264
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AAC
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MP3
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MPEG-4
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Enabled required filters only
Result:
A lightweight, optimized FFmpeg .so library, dramatically faster than precompiled versions.
2. JNI Layer for Android Integration
We built a custom JNI wrapper that:
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Sends commands from Java/Kotlin to native FFmpeg
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Handles progress callbacks
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Provides real-time result updates
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Manages memory to avoid crashes
3. High-Performance Video Processing Engine
The engine supports:
✔ Fast Video Trimming
Near-instant cut without re-encoding (when format allowed).
✔ Smooth Merging & Concatenation
Audio-sync safe, even for different resolutions.
✔ Custom Filters & Effects
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Brightness
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Contrast
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Speed change
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Reverse
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Color filters (LUTs)
✔ Watermarking & Text Overlays
FFmpeg drawtext/drawbox modules optimized for mobile.
✔ Audio Features
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Extract audio
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Add background music
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volume boost
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audio mixdown
✔ Format & Resolution Conversion
Full control over:
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bitrate
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fps
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resolution
4. Performance Optimization
We improved performance with:
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Multi-threaded FFmpeg builds
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neon SIMD optimizations for ARM
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pre-set command templates
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caching frequent operations
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memory-safe buffer handling in JNI
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reduced latency during encode
Result:
25–45% faster exports than generic FFmpeg Android builds.
5. UI Integration into the Video Editor App
We integrated the engine with the Android app’s UI:
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Timeline editor
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Real-time previews
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Export panel
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Filter selection UI
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Audio track mixer
Everything works offline — no cloud processing required.
📊 Architecture Diagram (Text Description)
📈 Results / Impact
🚀 Up to 45% Faster Video Exports
Compared to stock FFmpeg or third-party SDKs.
📱 Lightweight App Build
APK size significantly reduced by only including required codecs.
🔒 100% Offline Processing
Protects user privacy and avoids cloud costs.
🌍 Works on All Android Devices
armv7 + arm64 builds ensured wide coverage.
🎬 Full Professional Editing Features
Supported everything needed for a modern mobile editor.
😍 Better User Engagement
Smoother editing + faster exports → higher retention & positive reviews.
🏁 Conclusion
By creating a custom, high-performance video processing engine using native FFmpeg, we enabled the client to build a fast, powerful, offline Android video editor with professional-level capabilities. Optimizing FFmpeg at the source gave the app speed, stability, and flexibility unmatched by generic libraries.
Written by
Abhi
