video_compress_kit_android #

The Android implementation of video_compress_kit.

Usage #

You should not depend on this package directly. Add the app-facing package instead:

dependencies:
  video_compress_kit: ^0.0.1

The Android implementation is automatically endorsed and registered.

How It Works #

Video Compression Pipeline #

Uses Android's built-in MediaCodec hardware video encoder with MediaExtractor for demuxing and MediaMuxer for muxing. No bundled native libraries — the entire implementation rides on top of OS APIs, adding ~0 MB to your APK size.

Input MP4
  → MediaExtractor (demux video + audio tracks)
  → MediaCodec decoder (hardware H.264 decode)
  → Surface transfer
  → MediaCodec encoder (hardware H.264 encode)
      ├─ H.264 Profile: Baseline / Main / High (API 23+)
      ├─ Bitrate mode: VBR / CBR / CQ (API 21+)
      ├─ CQ quality: KEY_QUALITY (0–100)
      └─ Color standard: BT.601 / BT.709 (API 24+)
  → MediaMuxer + audio passthrough
  → Output MP4

Image Compression Pipeline #

Uses Android's built-in BitmapFactory for decoding and Bitmap.compress() for re-encoding. No third-party image libraries.

Input image (JPEG / PNG / WebP / etc.)
  → BitmapFactory.decodeFile (with inSampleSize for memory efficiency)
  → Scale to maxWidth / maxHeight (proportional)
  → Bitmap.compress(format, quality, outputStream)
      ├─ JPEG: CompressFormat.JPEG
      ├─ PNG:  CompressFormat.PNG
      └─ WebP: CompressFormat.WEBP / WEBP_LOSSY (API 30+)
  → ExifInterface: copy EXIF tags (if keepExif = true)
  → Output file

Per-Session Architecture #

Each compressVideo() call creates a VideoCompressor instance stored in a ConcurrentHashMap<String, VideoCompressor> keyed by sessionId. This enables:

• Concurrent compressions — multiple videos processed in parallel
• Per-session progress — each compressor reports progress tagged with its session ID
• Per-session cancellation — cancel a specific session without affecting others
• Cancel all — iterate the map and cancel every active session

┌──────────────────────────────────┐
│  VideoCompressKitAndroidPlugin   │
│                                  │
│  compressors: ConcurrentHashMap  │
│  ┌────────────┬────────────┐     │
│  │ "job-1"    │ "job-2"    │     │
│  │ Compressor │ Compressor │     │
│  └────────────┴────────────┘     │
│                                  │
│  cancelCompression("job-1")      │
│   → compressors["job-1"].cancel()│
│                                  │
│  cancelCompression(null)         │
│   → cancel ALL                   │
└──────────────────────────────────┘

Video Feature Support Matrix #

CQ fallback: Not all Android hardware encoders support BITRATE_MODE_CQ. The implementation wraps CQ configuration in a try/catch — if the encoder rejects CQ mode, it automatically falls back to VBR with the preset bitrate.

Image Feature Support Matrix #

Requirements #

Native APIs Used #

License #

MIT — see LICENSE.