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How to convert 64-bit WAV (RF64) and BWF [Mac Windows]

WAV 64-bit (or RF64) is an extended WAV format for supporting audio files with a size of over 4 GBytes.  It's actually for super high resolutions 352, 384 kHz and higher. The RF64-audio file has either *.wav or *.rf64 extension.
RF64 does not mean 64-bit bit depth. RF64 defines file size. Big WAV files with 64-bit bit depth may be stored in either RF64 or ordinary WAV format.


Author: Yuri Korzunov,
Audiophile Inventory's developer with 25+ year experience in digital signal processing,
author of the articles that make audio easy for beginners

How to convert to WAV RF64 (64 bit)

  1. Launch AuI ConverteR 48x44

  2. Open input file.
  3. Select target format .wav or .rf64, sample rate and bit depth.
  4. Push Start button.
    WAV/RF64 formats are switched automatically and transparently for user. Read details below...


WARNING: DVD-audio/video, Blu-Ray, DVD/BluRay/CD ISO are NOT supported.
For Modula-R version, SACD ISO, DSF, DFF are supported in proper configurations.
For ISO tracks, DSF, DFF longer than 3 minutes, FREE edition mutes 2-second silence in the output middle and has other restrictions. In batch conversion FREE version mutes 2 seconds in the output middle for second and the subsequent files.
Free version has processing sound quality identical commercial editions.


Audiophile music file converter
with WAV RF64 supportWAV RF64 64 bit audio file converter

    for playback music on:
        digital audio player (DAP),
        media server/streamer,
        car stereo.

    Resolution up to 64 bit /768 kHz, D1024
    Multichannel and stereo

    Clickless technologies
    Auto and manual artwork assigning to target files
    Easy-to-use software



How RF64 works

Audio converter AuI ConverteR 48x44 support WAV 64-bit according to RF64 specification.

  1. Output (converted) WAV file is created
    In its header, a dummy block ("JUNK" chunk by WAV specification) is added. It's fully compatible with an ordinaty WAV. Most players must ignore the block.
  2. After conversion starts, audio data are written to the WAV file.
  3. After the end of conversion and writing, the converter checks the real size of the output file.
    • If its size is more than 4 GBytes, "JUNK" block is replaced with "ds64" block with RF64 parameters (64-bit file length, etc.).
      Also, name of the first WAV block is replaced from "RIFF" with "RF64" and its size is set to the maximum value (0xFFFFFFFF in hex format).
      Size of block "data" (audio data) is replaced to 0xFFFFFFFF.
      Now ordinary WAV is transformed into WAV RF64 file.
    • If size of the file is lesser than 4 GB, the audio file stays ordinary WAV.
How ordinary WAV converted to WAV 64-bit (RF64)
How ordinary WAV converted to RF64 (WAV 64-bit)


RF64 settings

  1. If in AuI converteR's Settings > Metadata  > "Force 32-bit wav" switch is checked, block JUNK is not created and the next steps don't work.
    It's needed for compatibility with some players and software.
  2. For some pro audio applications, it needs to reserve a space for RF64 markers (time points of audio data). AuI ConverteR reserves the space in begin of this file for these markers.
    Audio players usually don't use markers. To avoid the marker place reserving, in Settings > Metadata > uncheck "No markers RF64" switch.
RF64 settings
RF64 or wav 64-bit settings


To assign BWF field, go to Settings > BWF:

BWF settings
Broadcast Wave Format settings





AuI ConverteR has several price/functionality options that allow saving your budget for the required functionality. You can expand Modula-R abilities later by purchasing new modules. Unlimited-time license, major updates (... 10.x > 11.x > 12.x > ... versions) are paid.

WARNING: Modula-R modules (parts of AuI ConverteR’s functionality) are NOT compatible with Free version.
ADD-ON modules work with certain CORE modules only (see details).
The module is license key received in order email. To activate module functionality, enter its key in Modula-R executable.
All "Modula-R" modules together have "PROduce-RD"'s abilities.
Full-featured "PROduce-RD" version is like a discount on price of full module kit of "Modula-R" version.

To expand functionality, module(s) (compatible with purchased major version number) may be ordered separately.
Modula-R license cannot be replaced with PROduce-RD.

* All prices on this page are in U.S. dollars without V.A.T. and other applicable taxes and fees. The prices are recommended. Information on this page is not a public offer.


How work 64-bit WAV (RF64) support


Read more about WAV