Audio Interchange File Format
Convert AIFF audio to MP3, WAV, or OGG directly in your browser — no upload, no server, no quality loss during transfer. FileDex uses FFmpeg WebAssembly to decode Apple's uncompressed audio format and re-encode it locally on your device.
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أسئلة شائعة
Can I convert AIFF to MP3 without losing quality?
MP3 is a lossy format, so some audio data is discarded during encoding. However, at 192 kbps VBR or higher, the difference is inaudible to most listeners in blind tests. FileDex converts AIFF to MP3 locally in your browser with no file uploads.
What is the difference between AIFF and WAV?
Both store uncompressed PCM audio at identical quality. AIFF uses big-endian byte order in an IFF container (Apple standard), while WAV uses little-endian in a RIFF container (Microsoft standard). WAV has broader cross-platform support; AIFF is preferred in macOS audio workflows.
Why are AIFF files so large?
AIFF stores uncompressed PCM audio — every sample at full precision with no compression. Stereo 16-bit 44.1 kHz AIFF uses approximately 10 MB per minute. Use FLAC for lossless compression at 50-70% of the original size, or MP3 for 10:1 lossy compression.
Is AIFF-C the same as AIFF?
AIFF-C is a compressed variant that adds a codec field to the COMM chunk, supporting IMA ADPCM, MACE, and other compression schemes. Standard AIFF is always uncompressed PCM. Most modern usage refers to uncompressed AIFF.
ما يميز .AIFF
Recording studios built on Macintosh hardware standardized around AIFF in the late 1980s, and the format persists in professional audio workflows today. Audio Interchange File Format was developed by Apple in 1988, based on Electronic Arts' IFF (Interchange File Format) chunked structure. AIFF stores uncompressed PCM audio — bit-for-bit identical to the source — making it a lossless archival format.
اكتشف التفاصيل التقنية
AIFF stores samples in big-endian byte order (Motorola 68000 convention), while WAV uses little-endian (Intel x86). The same 16-bit sample value 0x7FFF is stored as 7F FF in AIFF but FF 7F in WAV. A raw byte-copy between the two formats produces white noise. This endianness difference is the single most common cause of garbled audio when developers hand-roll format converters.
Chunk architecture
AIFF uses the IFF chunk model. Every chunk starts with a 4-byte ID, a 4-byte size field (big-endian), and then the payload. Required chunks:
- FORM — The outer container. The first four payload bytes spell "AIFF".
- COMM (Common) — Declares channel count, sample frame count, bit depth, and sample rate. The sample rate is stored as an 80-bit IEEE 754 extended precision float — a quirk inherited from the Macintosh's SANE (Standard Apple Numerics Environment).
- SSND (Sound Data) — Contains the raw PCM sample data plus an offset and block-size field for alignment.
Optional chunks include MARK (cue markers), INST (instrument parameters for samplers), NAME, AUTH, and ANNO (annotations). Loop points stored in INST and MARK chunks made AIFF the preferred format for hardware samplers like the Akai MPC and E-mu series throughout the 1990s.
AIFF-C: the compressed variant
Apple published AIFF-C (AIFF Compressed) to allow codecs inside the AIFF container. The FORM type changes from "AIFF" to "AIFC", and the COMM chunk gains a compression type field. Common compression types include sowt (little-endian PCM — the name is "twos" backwards), ima4 (IMA ADPCM at 4:1 compression), and NONE (big-endian PCM, identical to standard AIFF). In practice, most "AIFF" files in the wild are either standard AIFF or AIFF-C with NONE compression.
File sizes
| Parameters | Per minute | Per hour |
|---|---|---|
| 16-bit / 44.1 kHz / stereo (CD) | 10.1 MB | 605 MB |
| 24-bit / 48 kHz / stereo (broadcast) | 16.5 MB | 989 MB |
| 24-bit / 96 kHz / stereo (hi-res) | 33.0 MB | 1.98 GB |
| 32-bit float / 96 kHz / stereo (mixing) | 44.0 MB | 2.64 GB |
These sizes are identical to WAV at the same parameters — the container overhead difference is negligible.
AIFF vs. WAV in practice
Both formats carry uncompressed PCM. The practical differences: AIFF natively supports text metadata in NAME/AUTH/ANNO chunks, while WAV relies on INFO or BWF (Broadcast Wave) extensions that some tools ignore. WAV has a hard 4 GB file limit in its original spec (though RF64/BWF64 extends this). AIFF's 32-bit size fields impose the same 4 GB ceiling.
Logic Pro and GarageBand default to AIFF. Pro Tools defaults to WAV (BWF). Ableton Live and Reaper treat both identically. For cross-platform interchange, WAV is safer because Windows tools occasionally choke on AIFF's big-endian samples. For Mac-centric studios, AIFF remains the native choice.
Limitations
No lossy compression in mainstream use. No streaming support — the entire file must be accessible for playback. No native DRM. No metadata standard as mature as ID3 or Vorbis comments. For distribution, convert AIFF to FLAC (lossless, ~50% size reduction) or AAC/Opus (lossy, ~90% size reduction).
حوّل .AIFF إلى...
المرجع التقني
- نوع MIME
audio/aiff- Magic Bytes
46 4F 52 4D xx xx xx xx 41 49 46 46FORM header followed by AIFF signature at bytes 8-11.- المطوّر
- Apple Inc.
- سنة التقديم
- 1988
- معيار مفتوح
- لا
FORM header followed by AIFF signature at bytes 8-11.
البنية الثنائية
AIFF uses the IFF (Interchange File Format) container. The file begins with a 12-byte master header: 4-byte FORM signature (46 4F 52 4D), 4-byte big-endian file size (excluding the first 8 bytes), and 4-byte format identifier AIFF (41 49 46 46). The body contains chunks, each with a 4-byte ID, 4-byte big-endian size, and payload. The mandatory COMM (Common) chunk stores channel count (2 bytes), sample frame count (4 bytes), sample size in bits (2 bytes), and sample rate as an 80-bit IEEE 754 extended precision float. The SSND (Sound Data) chunk contains the raw PCM samples with an 8-byte sub-header (offset and block size fields). Optional chunks include MARK (cue markers), INST (instrument loop points), NAME, AUTH, and ANNO (annotations). AIFF-C adds a compression type field to the COMM chunk.
| Offset | Length | Field | Example | Description |
|---|---|---|---|---|
0x00 | 4 bytes | FORM Signature | 46 4F 52 4D (FORM) | IFF container identifier. All AIFF files start with these bytes. |
0x04 | 4 bytes | File Size | varies (big-endian) | Total file size minus 8 bytes (excludes FORM signature and this size field). Big-endian byte order. |
0x08 | 4 bytes | AIFF Identifier | 41 49 46 46 (AIFF) | Format type within the IFF container. AIFF for uncompressed, AIFC for AIFF-C compressed variant. |
0x0C | 4 bytes | COMM Chunk ID | 43 4F 4D 4D (COMM) | Common chunk — contains channel count, sample frames, bit depth, and sample rate. |
COMM+8 | 2 bytes | Number of Channels | 00 02 (stereo) | 1 = mono, 2 = stereo, up to 6 for surround configurations. |
COMM+14 | 10 bytes | Sample Rate | 40 0E AC 44 00 00 00 00 00 00 | 80-bit IEEE 754 extended precision float. Example encodes 44100 Hz. |
varies | 4 bytes | SSND Chunk ID | 53 53 4E 44 (SSND) | Sound Data chunk containing the raw PCM audio samples. |
نقاط الضعف
- Malformed COMM chunk with extreme channel count or sample rate values can trigger integer overflow in decoders that calculate buffer sizes without overflow checking
- Oversized annotation (ANNO) or name (NAME) chunks can cause heap buffer overflow in parsers with fixed-size metadata buffers
الحماية: FileDex processes AIFF files locally using FFmpeg WASM in a sandboxed browser environment. No data is sent to external servers.