Convert Standard MIDI File (.midi) to Apple Lossless Audio Codec (.alac) online for free. Fast, secure audio conversion with no watermarks or registration.
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Click Convert and download your .m4a file when it's ready.
MIDI (.midi) represents music as a structured sequence of performance commands rather than recorded sound. The format emerged from the collaboration of major synthesizer manufacturers in the early 1980s to create a universal instrument communication protocol. Today, .midi files remain essential in music education software (MuseScore, Finale, Sibelius exports), procedural game music engines, and electronic music production as a lightweight, editable representation of musical ideas.
ALAC (Apple Lossless Audio Codec) is Apple's answer to FLAC — a lossless compression scheme that reduces PCM audio to approximately 40-60% of its original size without discarding any data. Converting MIDI to ALAC renders the score through software synthesis and packages the result in Apple's lossless format, ideal for listeners who want perfect audio quality within the Apple ecosystem without the storage penalty of uncompressed AIFF.
Music educators who distribute practice tracks, sight-reading exercises, or theory demonstrations as MIDI files can convert to ALAC for Apple-device-equipped classrooms. Students receive consistent, lossless audio playback on their iPads and iPhones without needing MIDI player apps. The lossless quality ensures that subtle musical details — articulations, dynamic shading, instrument timbres — survive for analytical listening exercises.
Composers building personal archives of MIDI work can render their entire catalog to ALAC for Apple Music integration. ALAC files appear in the Music app with full metadata support (title, artist, album artwork, track numbers), enabling organized library management that raw MIDI files cannot provide. The lossless format guarantees the archive can be transcoded to any future format without generational loss.
The conversion begins with FFmpeg's MIDI decoder parsing the SMF header and building an event timeline indexed by absolute tick positions. Each tick is resolved to real time using the current tempo map. The synthesis engine loads instrument patches from a SoundFont and processes events in chronological order: note-on events trigger sample playback with velocity-mapped filter cutoff and amplitude; sustain pedal (CC64) holds notes beyond their key release; expression (CC11) provides real-time amplitude scaling. The mixed PCM output passes through the ALAC encoder, which applies linear prediction, adaptive rice coding, and frame-level optimization to compress losslessly within an M4A container.
ALAC encoding is mathematically lossless — the PCM recovered from ALAC decoding is identical to the synthesis output, sample for sample. This means the only quality variable is the SoundFont. Music education applications benefit from SoundFonts with clear, well-separated instrument timbres rather than heavily processed cinematic ones. A clean GM SoundFont with bright, distinct patches helps students identify individual instruments during ear training exercises. For composition archives, a more expressive, reverb-rich SoundFont produces a more enjoyable listening experience.
| Device | MIDI | ALAC |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Native |
| iPhone/iPad | Partial | Native |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No |
Resolution: N/A
Bitrate: 320 kbps
OGG Vorbis preferred
Resolution: N/A
Bitrate: 256 kbps
AAC format required
Resolution: N/A
Bitrate: 128 kbps
Lossless FLAC/WAV for best quality
Resolution: N/A
Bitrate: 128 kbps
MP3 mono for spoken word
MIDI to ALAC serves music educators and composers in the Apple ecosystem who need lossless audio from symbolic music data. The format integrates perfectly with Apple Music, iPad, and iPhone while preserving every detail of the synthesis.
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| No |
| Funktion | MIDI | ALAC |
|---|---|---|
| Fullstandigt namn | Standard MIDI File | Apple Lossless Audio Codec |
| Filandelse | .midi | .m4a |
| Bast for | Musical data format | Lossless |