Lilt

Lilt is a cross-platform command-line tool that converts Hi-Res FLAC and ALAC files to 16-bit FLAC files with a sample rate of 44.1kHz or 48kHz. Written in Go for excellent performance and cross-platform compatibility.

Lilt stands for "lightweight intelligent lossless transcoder". It is also a form of traditional singing common in the Goidelic speaking areas of Ireland, Scotland and the Isle of Man, though singing styles like it occur in many other countries. Features

• FLAC Support: Converts 24-bit FLAC files to 16-bit FLAC using SoX
• ALAC Support: Converts ALAC (.m4a) files to FLAC format
• 16-bit 44.1kHz/48kHz ALAC files are converted to FLAC with the same quality
• Hi-Res ALAC files are converted to 16-bit FLAC following the same rules as FLAC files
• Format Enforcement: Convert all audio files to a specific output format:
• FLAC: Convert all FLAC, ALAC, and MP3 files to 16-bit FLAC
• MP3: Convert all FLAC and ALAC files to 320kbps MP3 (preserves existing MP3 files)
• ALAC: Convert all FLAC and MP3 files to 16-bit ALAC (optimizes existing ALAC files)
• Downsamples high sample rate files:
• 384kHz, 192kHz, or 96kHz ? 48kHz
• 352.8kHz, 176.4kHz, 88.2kHz ? 44.1kHz
• Preserves existing 16-bit FLAC files without unnecessary conversion
• Preserves ID3 tags and cover art from original files using FFmpeg (default: enabled; use --no-preserve-metadata to disable)
• Copies MP3 files without modification (unless format enforcement is enabled)
• Optional: Copies JPG and PNG images from the source directory
• Docker support for containerized execution
• Cross-platform: Windows, macOS, Linux (x64, ARM64, x86, ARM)