# AAC to E-AC-3 Converter

Converts AAC 5.1/7.1 audio tracks to E-AC-3 while preserving all other streams (video, subtitles, metadata).

## Requirements

- Python 3.6+
- FFmpeg with E-AC-3 support

## Usage

```bash
# Preview conversions (recommended first step)
python aac2eac3.py /path/to/media --dry-run

# Convert to new files (original.eac.mkv)
python aac2eac3.py /path/to/media

# Overwrite original files (creates temporary backups)
python aac2eac3.py /path/to/media --overwrite

# Custom FFmpeg path (e.g., Jellyfin's FFmpeg)
python aac2eac3.py /path/to/media --ffmpeg /usr/lib/jellyfin-ffmpeg/ffmpeg
```

## Options

- `path` - Directory containing .mkv/.mp4 files (searches recursively)
- `--dry-run` - Show what would be converted without making changes
- `--overwrite` - Replace original files instead of creating new ones
- `--ffmpeg` - Path to FFmpeg binary (default: `ffmpeg`)

## What it does

- Scans directory for .mkv and .mp4 files recursively
- Identifies AAC audio tracks with 6 channels (5.1) or 8 channels (7.1)
- Converts those tracks to E-AC-3 @ 640 kbps
  - Note: 7.1 AAC is downmixed to 5.1 E-AC-3 (FFmpeg limitation)
- Copies all other streams unchanged (video, subtitles, other audio)
- Preserves all metadata (language tags, track titles, etc.)

## Features

- **Detailed progress tracking** - Shows file-by-file progress with conversion times
- **Smart skipping** - Automatically skips files without AAC 5.1/7.1 tracks
- **Comprehensive summary** - Displays statistics at the end (converted, skipped, failed, time)
- **Color-coded output** - Easy-to-read terminal output with visual indicators
- **Safe operation** - Creates temporary backups when using `--overwrite`

## Example output

```
════════════════════════════════════════════════════════════════════
  AAC to E-AC-3 Converter
════════════════════════════════════════════════════════════════════

Scanning: /media/movies
Found 5 media files

▶ [1/5] movie.mkv
  Track 1: AAC 6ch (eng) → E-AC-3 @ 640k
  Converting → movie.eac.mkv
✓ Completed in 45s (4.2 GB)

▶ [2/5] another_movie.mkv
  No AAC 5.1/7.1 tracks found - skipping

════════════════════════════════════════════════════════════════════
  Conversion Summary
════════════════════════════════════════════════════════════════════
  Total files scanned:     5
  Successfully converted:  3
  Skipped (no AAC):        2

  Total time:             3m 25s
  Average per file:       1m 8s
```