A comprehensive Android media transcoder supporting video, audio, and image format conversion. Leverages hardware acceleration via ffmpeg-kit-full-gpl on Android for efficient processing. Handles common formats such as MP4 for video; MP3 for audio; and JPEG for images. Ideal for learning Android media processing or building file converter apps.
Just for Fun – Since you can't really run FFmpeg via command line on phones, and most transcoding apps on the market ask for payments or VIP memberships, I decided to build my own.
As long as it runs, it's fine. Bug fixes are on a "when I feel like it" basis. Compatibility might be a bit iffy, but if you're willing to tinker, it might just work.
- Supports Three Major Media Types: Video, audio, and image transcoding. Covers almost all common formats.
- Based on FFmpeg: Uses
ffmpeg-kit-full-gplunder the hood for powerful decoding/encoding. - Multi-threaded Task Queue: Configure concurrent tasks (1~10), tasks are automatically queued.
- Real-time Progress Display: Shows transcoding progress, output file size, and size change percentage (↑ increase / ↓ decrease) directly in the task list.
- Detailed Parameter Adjustments:
- Video: Format (MP4/MKV/MOV…), Encoder (H.264/HEVC/VP9…), Resolution, Bitrate/CRF, Framerate, Aspect Ratio, 2-Pass Encoding, Rotate/Flip.
- Audio: Format (MP3/AAC/FLAC…), Encoder, Sample Rate, Bitrate, Channels, Volume Adjustment.
- Image: Format (JPEG/PNG/GIF…), JPEG Quality Adjustment.
- Smart Output Path: Choose to save output in the source file directory, or manually select any folder (SAF support).
- Task Management: Add, remove selected, clear list, stop all, start all – simple and straightforward.
- Global Settings: Adjust the number of concurrent threads to prevent your phone from lagging.
- Permission-Friendly (?) : Requires a fair number of permissions, but it's all for file reading/writing.
- Language: Java
- Minimum SDK: 28 (Android 9)
- FFmpeg Binding: ffmpeg-kit-full-gpl v6.0-2
- UI: Material Design 3 (via Material Components)
- Architecture Components: ViewModel + LiveData + RecyclerView
- File Access: Storage Access Framework (SAF) + File Descriptor Passthrough
com.masterxu.video_transcoder
│
├── MainActivity.java // Main UI
├── model
│ ├── TaskItem.java // Task Entity
│ └── TaskStatus.java // Status Enum
├── viewmodel
│ └── TaskViewModel.java // Task Management + Thread Pool
├── adapter
│ └── TaskListAdapter.java // List Adapter
├── dialog
│ ├── GlobalSettingsDialog.java // Global Settings Dialog
│ ├── VideoOptionsDialog.java // Video Options Dialog
│ ├── AudioOptionsDialog.java // Audio Options Dialog
│ └── ImageOptionsDialog.java // Image Options Dialog
├── utils
│ ├── FfmpegCommandBuilder.java // FFmpeg Command Builder
│ ├── FileUtils.java // SAF File Utilities
│ └── PermissionHelper.java // Permission Request Helper
└── worker
└── FfmpegTaskRunner.java // Thread for Executing Transcoding Tasks
Click the menu item "Global Settings" in the top right corner:
- Thread Count: Number of tasks running simultaneously (1~10), default is 5.
Note: Setting this too high might cause your phone to overheat or lag. Adjust based on your device's performance.
- Android Studio Flamingo or newer
- Gradle 7.4+
- Android SDK 34
- Clone the repository
git clone https://github.com/xumous/android-media-transcoder-example.git
- Open the project in Android Studio and wait for Gradle to sync.
- Connect a device or start an emulator, then click Run.
dependencies {
implementation 'androidx.appcompat:appcompat:1.6.1'
implementation 'com.google.android.material:material:1.11.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
implementation 'androidx.recyclerview:recyclerview:1.3.2'
implementation 'androidx.lifecycle:lifecycle-viewmodel:2.7.0'
implementation 'androidx.lifecycle:lifecycle-livedata:2.7.0'
implementation 'androidx.documentfile:documentfile:1.0.1'
implementation 'com.arthenica:ffmpeg-kit-full-gpl:6.0-2'
}- Permissions: As mentioned, please grant all necessary storage permissions in system settings, especially "All files access" on Android 11+.
- Transcoding Performance: FFmpeg is CPU-intensive. Long-duration, high-load transcoding may lead to overheating and rapid battery drain.
- Format Compatibility: Some encoders may require hardware support (e.g., hardware-accelerated encoding). If they fail, the process will fall back to software encoding automatically.
- Canceling Tasks: Clicking "Stop All" or removing a running task will terminate the FFmpeg process immediately, but any data already written will not be deleted.
- Known Bugs: The progress bar might occasionally act up, and size change calculations could be off. But hey, "as long as it runs" 😅.
A: Due to Android SAF restrictions, some directories (like DCIM, Downloads) may not have direct write permissions. Please choose "Select Directory" and manually pick a folder where your app has write access (e.g., a dedicated folder you created).
A: The input file might be corrupted, or FFmpeg might not be able to decode it. Check the Logcat logs (search
for FfmpegTaskRunner) for detailed errors. It could also be that the maximum number of concurrent tasks is reached;
just wait for others to finish.
A: Currently, no Service is implemented. Tasks will be forcefully stopped if you exit the app. A foreground service might be considered in future versions.
A: FFmpegKit full-gpl includes hardware-accelerated encoders like NVENC, VAAPI, etc. However, hardware acceleration
support on Android depends on the device's codecs. If your device supports it, you could manually add encoders
like h264_mediacodec in the code, though they are not included in the default encoder list.
A: This might be due to incompatibility between the encoder and the container (e.g., putting HEVC video into an AVI container). Stick to mainstream combinations (like H.264 + MP4, HEVC + MKV).
The code in this project is licensed under the GNU General Public License v3.0.
Due to the use of ffmpeg-kit-full-gpl (GPL version), the entire project must
comply with the GPL license.
See the LICENSE file for details.
- FFmpeg: The GOAT.
- arthenica/ffmpeg-kit: Saved me the trouble of compiling FFmpeg myself.
- All paid transcoding apps for the "motivation": If you weren't so expensive, I wouldn't have built this myself. 🤪
Last Updated: March 11, 2026
**Project URL **: https://github.com/xumous/android-media-transcoder-example
Issues: Feel free to open an issue, but don't expect an immediate fix. It's just for fun～