MasterEditVideo

An Android video editing application powered by OpenGL ES for real-time GPU rendering, ExoPlayer for media playback, and FFmpeg for video processing.

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Table of Contents

• Features
• Architecture
• Project Structure
• Rendering Pipeline
• Transitions
• Tech Stack
• Requirements
• Getting Started
• Permissions

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Features

Feature	Status
Play video	✅
Play image	✅
Play background music	✅
Apply transitions (25+)	✅
Timeline editor	✅
Media picker (video & image)	✅
Audio volume mixing	✅
Merge video and image	🚧 In progress
Apply filters (Brightness, Contrast, Gamma)	🚧 In progress
Apply effects	🚧 In progress
Multi-screen graph layouts	🚧 In progress
Trim video	🔲 Planned
Trim music	🔲 Planned
Export edited video	🔲 Planned

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Architecture

The project follows a multi-module architecture with a clear separation between the UI layer and the core editing engine.

┌─────────────────────────────────────────────────────────────┐
│                        app module                           │
│  ┌─────────────┐ ┌────────────┐ ┌─────────────────────────┐│
│  │  Activities  │ │  Fragments │ │  Adapters / Dialogs     ││
│  │  ┌────────┐  │ │ Transition │ │  AdapterMedia           ││
│  │  │  Main  │  │ │ Filter     │ │  AdapterSpecial         ││
│  │  │Activity│  │ │ Effect     │ │  AdapterMusic           ││
│  │  └────────┘  │ │ Graph      │ │  DialogTool             ││
│  │  ┌────────┐  │ │ Special    │ │  DialogMixVolume        ││
│  │  │ Media  │  │ │ PickMusic  │ │                         ││
│  │  │ Pick   │  │ └────────────┘ └─────────────────────────┘│
│  │  └────────┘  │                                           │
│  └─────────────┘  Singleton / LiveData / Retrofit           │
└──────────────────────────┬──────────────────────────────────┘
                           │ depends on
┌──────────────────────────▼──────────────────────────────────┐
│                    masteredit module                         │
│  ┌──────────────────────────────────────────────────────┐   │
│  │              ManagerPlayerMedia (Orchestrator)        │   │
│  │  ┌──────────────┐ ┌────────────┐ ┌───────────────┐  │   │
│  │  │ VideoPlayer  │ │  Music     │ │  PreViewLayout│  │   │
│  │  │ Control      │ │  Player    │ │  Control      │  │   │
│  │  │  └ExoManager │ │  Control   │ │  └GLPlayerView│  │   │
│  │  └──────────────┘ └────────────┘ └───────────────┘  │   │
│  │  ┌──────────────────────────────────────────────────┐│   │
│  │  │           SpecialPlayControl                     ││   │
│  │  │  Transitions │ Filters │ Effects │ Graphs        ││   │
│  │  └──────────────────────────────────────────────────┘│   │
│  └──────────────────────────────────────────────────────┘   │
│  ┌──────────────┐ ┌───────────────┐ ┌───────────────────┐  │
│  │  GL Renderer  │ │  GLSL Shaders │ │  Models & Enums   │  │
│  └──────────────┘ └───────────────┘ └───────────────────┘  │
└─────────────────────────────────────────────────────────────┘

Key Components

Component	Role
ManagerPlayerMedia	Central orchestrator that coordinates video playback, music, transitions, and effects
VideoPlayerControl	Wraps ExoPlayer for video/image playback and media queue management
MusicPlayerControl	Manages background music playback and volume
PreViewLayoutControl	Manages the OpenGL preview surface and filter chains
SpecialPlayControl	Handles transitions, effects, and graph layout rendering
GLPlayerRenderer	Core OpenGL ES renderer with shader-based processing
TimeLineControl	Visual timeline editor with track management

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Project Structure

MasterEditVideo/
├── app/                                    # UI & Application module
│   └── src/main/java/com/dongnh/mastereditvideo/
│       ├── app/                            # Application class
│       ├── base/                           # Base API response models
│       ├── const/                          # Event & media constants
│       ├── model/                          # Data models (Music, Tab, MixSound)
│       ├── singleton/                      # Shared LiveData state
│       ├── utils/
│       │   ├── adapter/                    # RecyclerView adapters
│       │   ├── control/                    # Timeline & duration controls
│       │   ├── dialog/                     # Tool & volume dialogs
│       │   ├── exts/                       # Kotlin extensions
│       │   ├── interfaces/                 # Callback interfaces
│       │   ├── retrofit/                   # Network layer (Retrofit + OkHttp)
│       │   └── view/                       # Custom views
│       └── view/
│           ├── main/                       # MainActivity (main editor)
│           ├── pickmedia/                  # MediaPickActivity
│           ├── transition/                 # TransitionFragment
│           ├── filter/                     # FilterFragment
│           ├── effect/                     # EffectFragment
│           ├── graph/                      # GraphFragment
│           ├── special/                    # SpecialFragment
│           └── pickmusic/                  # PickMusicFragment
│
├── masteredit/                             # Core editing engine library
│   └── src/main/
│       ├── java/com/dongnh/masteredit/
│       │   ├── base/                       # Abstract transition classes
│       │   ├── const/                      # Filter, media, transition constants
│       │   ├── control/                    # Player & preview controls
│       │   ├── eglcore/                    # EGL configuration
│       │   ├── enums/                      # Format, resource, scale enums
│       │   ├── filter/                     # GL filters (Brightness, Contrast, Gamma)
│       │   ├── gl/                         # OpenGL utilities & FBO management
│       │   ├── graph/                      # Multi-screen layout effects
│       │   ├── manager/                    # ManagerPlayerMedia
│       │   ├── model/                      # MediaModel, MusicModel, SpecialModel
│       │   ├── render/                     # GLPlayerRenderer
│       │   ├── transition/                 # 25+ transition effects
│       │   └── utils/                      # ExoManager, extensions, custom views
│       └── assets/
│           ├── transition/                 # Transition JSON + thumbnails + GLSL shaders
│           ├── graph/                      # Graph layout JSON + thumbnails + shaders
│           ├── filter/                     # Filter definitions
│           └── effect/                     # Effect definitions + FFmpeg shaders
│
├── build.gradle                            # Root build config
├── settings.gradle                         # Module settings
└── gradle.properties                       # Gradle JVM & AndroidX config

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Rendering Pipeline

The app uses a custom OpenGL ES rendering pipeline to process and display video frames in real-time:

  ┌──────────────┐     ┌──────────────────┐     ┌───────────────────┐
  │  Media Files  │────>│    ExoPlayer     │────>│  SurfaceTexture   │
  │ (Video/Image) │     │  (decode frames) │     │  (frame buffer)   │
  └──────────────┘     └──────────────────┘     └────────┬──────────┘
                                                         │
                                                         ▼
                                              ┌─────────────────────┐
                                              │   GLPlayerRenderer  │
                                              │  (OpenGL ES 2.0)    │
                                              └────────┬────────────┘
                                                       │
                        ┌──────────────────────────────┼──────────────────┐
                        │                              │                  │
                        ▼                              ▼                  ▼
              ┌──────────────────┐        ┌─────────────────┐   ┌──────────────┐
              │   Filter Chain   │        │   Transitions   │   │    Graph     │
              │ Brightness       │        │  (GLSL shaders) │   │   Layouts    │
              │ Contrast         │        │  Progress-based │   │  2/3/4/6     │
              │ Gamma            │        │  animation      │   │  screen      │
              │ LUT              │        │  (0.0 → 1.0)    │   │  splits      │
              └────────┬─────────┘        └────────┬────────┘   └──────┬───────┘
                       │                           │                   │
                       └───────────────┬───────────┘───────────────────┘
                                       ▼
                              ┌──────────────────┐
                              │   GLPlayerView   │
                              │  (Preview Output) │
                              └──────────────────┘

Transition Architecture

Each transition effect follows a three-layer pattern:

  ┌─────────────────────┐
  │  *Transition class  │  Logic & lifecycle (extends AbstractTransition)
  │  e.g. FadeTransition│
  └─────────┬───────────┘
            │ uses
  ┌─────────▼───────────┐
  │  *TransDrawer class │  OpenGL draw calls & texture binding
  │  e.g. FadeTransDrawer
  └─────────┬───────────┘
            │ uses
  ┌─────────▼───────────┐
  │  *TransShader class │  GLSL vertex + fragment shaders
  │  e.g. FadeTransShader
  └─────────────────────┘

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Transitions

25+ built-in transition effects, all rendered via GLSL shaders:

Window Slice	Simple Zoom	Cross Zoom	Luminance Melt	Cross Hatch
Wipe Right	Wipe Left	Wipe Down	Wipe Up	Dreamy Zoom
Fade	Directional Wipe	Wind	Inverted Page Curl	Swap
Cube	Circle Open	PinWheel	Angular	Hexagonalize
Pixelize	Perlin	Bounce

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Tech Stack

Core

Technology	Version	Purpose
Kotlin	1.7.20	Primary language
Android Gradle Plugin	7.3.1	Build system
OpenGL ES 2.0	-	Real-time GPU rendering
ExoPlayer	2.18.2	Media playback (video, audio)
FFmpeg Kit	5.1 (min)	Video processing & encoding
GPUImage	2.1.0	GPU-based image filtering

Android Jetpack & UI

Library	Version	Purpose
Core KTX	1.9.0	Kotlin extensions for Android
AppCompat	1.6.0	Backward-compatible UI
Material Components	1.7.0	Material Design UI
ConstraintLayout	2.1.4	Flexible layouts
RecyclerView	1.2.1	Scrollable lists
Lifecycle (LiveData + ViewModel)	2.5.1	Reactive state management
Data Binding	-	View binding
Flexbox	3.0.0	Flexible box layouts

Networking & Data

Library	Version	Purpose
Retrofit	2.9.0	REST API client
OkHttp	5.0.0-alpha.11	HTTP client + logging
Gson	2.10.1	JSON serialization
Glide	4.14.2	Image loading & caching

Utilities

Library	Version	Purpose
Timber	5.0.1	Logging
CircleImageView	3.1.0	Circular image views

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Requirements

• Android Studio: Arctic Fox or later
• Min SDK: 24 (Android 7.0 Nougat)
• Target SDK: 33 (Android 13)
• Java: 1.8+
• Kotlin: 1.7.20+

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Getting Started

1. Clone the repository

   git clone https://github.com/user/MasterEditVideo.git

2. Open in Android Studio

   Open the project root directory in Android Studio.

3. Sync Gradle

   Let Android Studio download all dependencies and sync the project.

4. Build & Run

   Select a device or emulator (API 24+) and click Run.

Note: The app runs in landscape mode by default.

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Permissions

Permission	Purpose	API Level
READ_EXTERNAL_STORAGE	Access media files on device	< 33
WRITE_EXTERNAL_STORAGE	Save exported videos	< 33
READ_MEDIA_IMAGES	Access images	33+
READ_MEDIA_VIDEO	Access videos	33+
READ_MEDIA_AUDIO	Access audio files	33+
INTERNET	Download music & assets	All
ACCESS_NETWORK_STATE	Check network connectivity	All

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License

This project is for demo and educational purposes.