Convert Standard MIDI (.mid) to Apple Lossless Audio Codec (.alac) online for free. Fast, secure audio conversion with no watermarks or registration.
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MID (Standard MIDI File) encodes musical performance as a sequence of instructions — note events, velocity, timing, channel assignments, pitch bends, and control changes. MIDI files are extraordinarily compact (10-100 KB) because they contain no audio, only a recipe for producing music. The actual sound depends entirely on the synthesizer interpreting these instructions.
ALAC (Apple Lossless Audio Codec) compresses audio without losing any data — every PCM sample is perfectly preserved. Converting MID to ALAC renders the MIDI performance through a software synthesizer and saves the result as losslessly compressed audio. This gives you a space-efficient Apple-ecosystem-compatible file that preserves the full quality of the synthesis.
MIDI's dependency on external synthesizers means playback is unpredictable across devices. ALAC captures a specific rendered version with bit-perfect audio preservation while using roughly 50-60% of the space that uncompressed AIFF or WAV would require. For Apple users, ALAC integrates seamlessly with iTunes, Apple Music, iPhone, iPad, and Mac.
ALAC is the ideal format when you need lossless archival of a MIDI rendering within Apple's ecosystem. Unlike AAC, no audio data is discarded during encoding. Unlike AIFF, the file is significantly smaller. This makes ALAC the best balance of quality and efficiency for MIDI renders destined for Apple devices.
FFmpeg decodes the MIDI file's event stream using its built-in MIDI decoder and routes events to a software synthesizer loaded with a SoundFont bank. The synthesizer generates PCM audio by mapping MIDI program numbers to instrument patches, applying note-on/off with velocity-scaled amplitude, processing pitch bend and modulation, and mixing all 16 MIDI channels to a stereo output. This PCM stream is then compressed using the ALAC encoder (lossless — every sample is recoverable) and packaged in an M4A (MPEG-4) container with proper metadata atoms.
ALAC encoding is mathematically lossless — the decoded output is bit-identical to the PCM input. Therefore, the only quality variable is the synthesizer and SoundFont. A SoundFont with 24-bit samples, multiple velocity layers, and release samples produces natural-sounding results. The default GM bank sounds functional but synthetic. ALAC simply preserves whatever the synthesizer outputs, with 50-60% size reduction compared to raw PCM.
| Device | MID | 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
MID to ALAC renders MIDI instructions into losslessly compressed audio optimized for Apple's ecosystem. The SoundFont determines musical quality; ALAC preserves it bit-perfectly.
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| No |
| Характеристика | MID | ALAC |
|---|---|---|
| Полное название | Standard MIDI File | Apple Lossless Audio Codec |
| Расширение | .mid | .m4a |
| Лучше всего подходит для | Musical performance data | Lossless |