App Profile: Medra

# Medra - Media Compression Tool

A clean and efficient iOS app for compressing images, videos, and audio files. Extensive customization options to meet your personalized needs. Runs locally without network, protecting your privacy and security.

## Core Features

- Support batch selection of images, videos, and audio (up to 20 files)
- Support multiple media formats
- Images: JPEG/PNG/HEIC/WebP/AVIF/GIF
- Videos: MOV/MP4/M4V/WebM
- Audio: MP3/M4A/AAC/WAV/FLAC/OGG
- Real-time processing progress display
- Intelligent quality protection mechanism

## Three Main Media Types

### 1. Video Tools

#### Video Compression

- Support MOV/MP4/M4V formats
- Use FFmpeg hardware-accelerated encoding (VideoToolbox)
- **Strictly preserves original video codec** (H.264, HEVC, VP9, AV1) - no transcoding unless necessary
- **Estimated Time Remaining (ETA)** display for long tasks
- Adjustable resolution (Original/4K/2K/1080p/720p)
- Adjustable frame rate (23.98-60 fps, only supports lowering frame rate)

- Bitrate control:
- **Auto Mode** (default): intelligently adjusts based on target resolution
- 720p ≈ 1.5 Mbps
- 1080p ≈ 3 Mbps
- 2K ≈ 5 Mbps
- 4K ≈ 8 Mbps
- **Custom Mode**: manually set bitrate (500-15000 kbps)
- Actual bitrate may be lower than target (VideoToolbox dynamically adjusts based on content complexity to optimize efficiency)
- Smart decision: preserve original file if compressed version is larger

#### Video Format & Codec Conversion

- Batch convert video formats: MP4 ↔ MOV ↔ M4V ↔ WebM
- Lossless conversion (where possible), maintaining original quality
- **Smart Audio Copy**: Automatically copies audio stream when compatible to avoid re-encoding
- **Smart Encoding**: Automatically uses hardware acceleration (VideoToolbox) for H.264/HEVC or VP9 for WebM when transcoding is necessary
- **Bitrate Preservation**: Maintains original video bitrate during transcoding to minimize quality loss

#### Video to Animation

- Convert video to animated WebP, AVIF, or GIF
- **Auto-optimized**: Uses optimized presets (15 fps, high quality) for best balance of size and quality
- **High Efficiency**: Direct AVIF conversion using libaom-av1 for superior compression

#### Extract Audio

- Extract audio track from video files
- Save as MP3, M4A, AAC, FLAC, WAV, or OGG

### 2. Image Tools

#### Image Compression

- Support JPEG/PNG/HEIC/WebP/AVIF/GIF formats
- Use MozJPEG for high-quality JPEG compression
- PNG compression using pngquant + optional Zopfli (lossy quantization + lossless deflate)
- **Animated WebP/AVIF/GIF Support**:
- Auto-detect animated files
- Option to preserve animation or convert to static image
- Frame-by-frame compression, maintaining timeline information
- Smart fallback: preserve original file if compressed lossless format is larger
- Visual indicator: clearly display animation status and frame count
- Adjustable compression quality (10%-100%)
- Support resolution adjustment (Original/4K/2K/1080p/720p)
- Auto orientation detection (landscape/portrait)
- Smart decision: preserve original file if compressed version is larger

#### Image Format Conversion

- Batch convert image formats: JPEG ↔ PNG ↔ WebP ↔ HEIC ↔ AVIF ↔ GIF
- No compression, only format modification

### 3. Audio Tools

#### Audio Compression

- Support MP3, M4A, AAC
- 8 bitrate options (32-320 kbps)
- 7 sample rate options (8-48 kHz)
- Channel selection (mono/stereo)
- Smart quality protection: prevent low-quality audio from being "upscaled"
- Smart decision: preserve original file if compressed version is larger

#### Audio Format Conversion

- Batch convert audio formats: MP3 ↔ M4A ↔ FLAC ↔ WAV ↔ WebM
- Lossless conversion (where possible)