WMA to FSSD Converter

Decode WMA to 8-bit unsigned PCM raw audio data

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Raw Audio Output

FSSD provides bare 8-bit PCM from WMA for embedded systems.

Online Processing

No tools needed — convert WMA to FSSD in your browser.

Minimal Overhead

Raw PCM encodes from WMA almost instantly.

How to convert WMA to FSSD

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose fssd or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your fssd file right afterwards

About formats

WMA (Windows Media Audio) is a family of proprietary audio codecs developed by Microsoft and first released in 1999 as part of the Windows Media framework. Created to compete with MP3 and AAC, WMA Standard uses perceptual coding to deliver what Microsoft claimed was near-CD quality at bitrates as low as 64 kbps — roughly half the data rate MP3 typically needed for comparable results. The codec family grew to include WMA Professional for surround sound and high-resolution audio, WMA Lossless for bit-perfect archival compression, and WMA Voice optimized for spoken content at very low bitrates. Deep integration with Windows, Windows Media Player, and the Zune ecosystem gave WMA a strong distribution advantage throughout the 2000s, and digital rights management (DRM) support made it attractive to online music stores of that era. Encoding and decoding are handled natively by Windows, requiring no third-party software for playback on any Windows machine. Cross-platform support has improved through libraries like FFmpeg and GStreamer, though WMA remains less universally compatible than MP3 or AAC on non-Microsoft devices. The format still appears in legacy media libraries, though newer codecs have largely taken its place for streaming and portable use.
Initial release: 1999
FSSD is a raw audio format that originated in the classic Macintosh ecosystem, where Farallon Computing's MacRecorder hardware (1988) stored digitized sound as unsigned 8-bit PCM in resource fork entries tagged with the 'FSSD' type code. In modern audio processing tools such as SoX, FSSD is treated as an alias for the u8 (unsigned 8-bit) raw format — headerless files containing a flat stream of single-byte amplitude samples, where each value from 0 to 255 represents an audio level with 128 as the center point. Because there is no header, playback parameters like sample rate and channel count must be provided externally. The original MacRecorder typically captured at rates up to 22 kHz in mono, though any sample rate is valid when interpreting the raw data. FSSD and its compressed companion format HCOM (which adds Huffman compression to the same underlying data) were the standard audio formats for early Mac multimedia: HyperCard stacks, educational CD-ROMs, and system alert sounds of the late 1980s and early 1990s relied heavily on this encoding. One advantage of the raw FSSD format is trivial parseability — with no container overhead, the audio data begins at byte zero and can be read by any tool capable of processing unsigned 8-bit PCM. The format's historical significance also makes it practically relevant for digital archivists: converting FSSD recordings to modern containers like WAV preserves the original audio content losslessly, since the raw samples only need a header prepended, not any form of transcoding.
Developer: Farallon Computing
Initial release: 1988

Frequently Asked Questions

Why convert WMA to FSSD?

FSSD provides raw 8-bit unsigned PCM data that embedded controllers and vintage systems expect. WMA requires a complex decoder these devices lack, so FSSD conversion bridges the gap.

Which tools and devices work with FSSD files?

SoX reads and writes FSSD on modern platforms. Raw audio editors, embedded firmware loaders, and certain vintage Macintosh sound tools also handle the format for playback or further processing.

Why choose FSSD over WAV for embedded use?

Some embedded microcontrollers need headerless raw byte streams they can feed directly to a DAC. FSSD delivers bare 8-bit PCM without the RIFF container overhead that WAV carries.

Does the conversion from WMA to FSSD lose quality?

WMA is decoded to PCM first, then stored as 8-bit unsigned samples in FSSD. The 8-bit depth limits dynamic range to about 48 dB, so detail is reduced compared to the original WMA encoding.

Can I process several WMA files to FSSD at once?

Yes — upload a batch of WMA files and Convertio generates an FSSD version of each in parallel. Download the results individually or as a single archive when encoding completes.