RMVB to AIFF Converter

RMVB to AIFF Converter

AIFF is Apple's Audio Interchange File Format, published in 1988 and built on Electronic Arts' Interchange File Format chunk structure. It stores big-endian uncompressed PCM, which is why it has been a first-class citizen in Logic Pro, GarageBand and QuickTime for decades. RMVB is the opposite kind of file: a RealNetworks container whose audio is a lossy, low-rate RealAudio stream. This converter decodes that stream on our servers and writes it out as PCM, discarding the RealVideo picture track. It is a rescue-and-compatibility operation, not a quality upgrade — the sections below spell out exactly what you get.

AIFF Output at a Glance

The RMVB Source at a Glance

How to Convert RMVB to AIFF

1. Upload Your RMVB File: Drop the .rmvb onto the page or click "Add Files". You can queue several and they all convert with the same settings.
2. Pick an Audio Codec: The dropdown offers PCM 16-bit Big Endian, PCM 16-bit Little Endian, PCM A-law and PCM mu-law. Big Endian is selected for you and is the one that produces a plain, maximally compatible AIFF — see the section below before changing it.
3. Set Audio Channel, Audio Sample Rate and Trim (Optional): Both Audio Channel and Audio Sample Rate start on ORIGINAL, which mirrors the source exactly. Force Mono or Stereo, or pin 8000, 12000, 16000, 24000, 44100 or 48000 Hz if your session demands a fixed rate. Trim starts on Unchanged; switch it on and enter a Start time and Duration to export a single cue.
4. Convert and Download: Click Convert and save the AIFF. Your file is uploaded over an encrypted connection, decoded on our servers, and both the upload and the result are deleted automatically after a few hours. No sign-up, no watermark.

The Four PCM Choices, and Which One Is Really an AIFF

The Audio Codec dropdown looks like four flavours of the same thing. It is not: only one of them writes a file whose header actually says AIFF. Checking the first sixteen bytes of each output from the same RealMedia source made the split obvious.

• PCM 16-bit Big Endian (default) — header reads FORM … AIFF. This is the original, unambiguous format that every AIFF-aware application understands. Use it unless you have a concrete reason not to.
• PCM 16-bit Little Endian — header reads FORM … AIFC. This is the byte-swapped variant macOS calls sowt; there is no compression involved, only a different byte order. Modern Apple software is happy with it, older cross-platform tools sometimes are not.
• PCM A-law and PCM mu-law — also FORM … AIFC, and genuinely companded: 8 bits per sample instead of 16. On a six-second test clip the mu-law file came out at 48,232 bytes against 96,374 bytes for the 16-bit PCM version — half the size, at telephony-grade quality. Reasonable for speech archives, wasteful of quality for music.
• A note on size: there is no bitrate or quality control on this page at all, because PCM has none. The only levers on file size are Audio Sample Rate, Audio Channel and Trim. If you need a small file, an AIFF is the wrong target — go to RMVB to MP3 or RMVB to FLAC instead.

Frequently Asked Questions

Will converting RMVB audio to AIFF improve the sound quality?

No. The audio inside an RMVB is lossy, almost always RealNetworks' Cook codec — an MDCT transform codec introduced in 1998 and named after its author, Ken Cooke. AIFF is uncompressed, but "uncompressed" only guarantees that nothing further will be discarded; it cannot rebuild what the original encode already removed. The AIFF will sound like the RealAudio source did, in a format your editor opens natively and at a considerably larger size. The honest reason to run this conversion is rescue and edit-readiness, not fidelity.

Why is the AIFF so much larger than the original RMVB?

Because AIFF stores raw samples while RMVB packed both a picture track and a heavily compressed audio track into a container designed for small downloads. Uncompressed audio costs sample rate × bit depth × channels: at 44.1 kHz, 16-bit, stereo that is 1,411,200 bits per second, which measured out to roughly 10.6 MB per minute in testing. A soundtrack that occupied a few megabytes inside the RMVB can therefore expand to tens or hundreds of megabytes as AIFF. That is the storage price of PCM, not evidence of added quality.

What bit depth does the output use, and can I get 24-bit?

Sixteen bits per sample, which is CD depth and the most widely compatible AIFF encoding. This page's Audio Codec dropdown exposes 16-bit PCM in both byte orders plus the two 8-bit G.711 options; deeper formats are not offered here. That is not a real limitation for this source — a low-rate lossy RealAudio stream carries nowhere near 16 bits of usable dynamic range, so writing 24-bit samples would enlarge the file without capturing anything extra.

Does the AIFF keep the original sample rate, or resample to 44.1 kHz?

It keeps the source rate as long as Audio Sample Rate is left on ORIGINAL. Converting a test RealMedia clip whose audio was 8 kHz mono produced an 8 kHz mono AIFF — no upsampling happened. Set the dropdown explicitly if a DAW session requires a fixed rate, but be aware that raising the rate only interpolates: it enlarges the file and adds no detail that was not in the RealAudio stream.

What is the difference between AIFF and AIFF-C, and which one do I get?

AIFF holds uncompressed PCM only; AIFF-C is the extended variant that can also carry compressed payloads, and it announces itself with AIFC instead of AIFF in the header. On this page the default PCM 16-bit Big Endian gives you a plain AIFF, while the little-endian, A-law and mu-law choices all produce AIFF-C. Confusingly, little-endian AIFF-C is not compressed at all — it is just byte-swapped PCM. If an old application rejects your file, switching back to Big Endian is the first thing to try.

Should I extract to AIFF or to WAV?

They store the same thing; the difference is byte order and ecosystem. AIFF is big-endian and native to Apple's tools, WAV is little-endian and the default on Windows. If the project lives in Logic Pro, GarageBand or Pro Tools, AIFF is the natural fit. If it lives in Windows-centric software or a game engine, take the same audio through RMVB to WAV instead. Neither one adds or removes quality relative to the other.

Does this work if the RMVB has no audio, or a codec that fails to decode?

If the file genuinely has no audio stream there is nothing to write and you should not expect a usable AIFF. RealMedia's decoders cover the RealVideo 1.0–6.0 line and the RealAudio family including Cook, RealAudio 1.0 and 2.0, SIPR and RealAudio Lossless, so most surviving files decode; the ones that fail are usually truncated downloads or files carrying RealNetworks rights management rather than exotic codecs. Playing the source in VLC first is the quickest way to tell which situation you are in.

How is my file handled, and how long do you keep it?

Your RMVB is uploaded over an encrypted connection, decoded on our servers, and the AIFF is returned to you. Both the upload and the converted file are deleted automatically after a few hours. There is no sign-up, no watermark, and files are never shared or made public.