.dsf File Extension

What kind of file is a .dsf?

A .dsf file is normally a DSD Stream File, Sony's container for Direct Stream Digital audio. DSD represents sound as a one-bit pulse-density stream sampled much faster than the multi-bit PCM used in WAV and most FLAC files. Software commonly labels the format with the conventional audio/x-dsf MIME type, but IANA has not registered that media type.¹²

A genuine DSF file starts with ASCII DSD , including the trailing space. In hexadecimal, those first four bytes are 44 53 44 20. Its header points to a fmt chunk, a data chunk, and an optional ID3v2 tag. Sony's version 1.01 specification defines mono through 5.1-channel layouts, 2.8224 MHz or 5.6448 MHz sample rates, and 4,096-byte sample blocks per channel.¹

How do I open a .dsf on my computer?

Use a DSD-aware player or converter:

• Windows and macOS: Sony Hi-Res Audio Player supports DSF, with available rates depending on the connected output device.³
• Windows, macOS, and Linux: FFmpeg can inspect, decode, and convert DSF files.⁴
• Hi-fi playback: A compatible desktop player may convert DSD to PCM, while native DSD output also requires a suitable driver, transport mode, and DAC.

Mainstream browsers do not normally decode DSF. If a web player stays silent, download the file and open it locally. Check for the DSD signature when the contents may not match the filename.

Poly support for .dsf

Poly recognizes .dsf as audio, stores and syncs the original, and makes its filename and basic file properties searchable. It opens in Poly's audio-player interface, but playback depends on browser support and is therefore limited.

Poly does not currently extract DSF duration or tags, create a transcript or audio-similarity index, or make the encoded recording available to the Poly agent. Convert a working copy to FLAC or WAV before upload when you need dependable playback, content search, or agent understanding. Keep the DSF original when native DSD playback or provenance matters.

History of .dsf

Sony documented the DSF container in the mid-2000s for storing DSD as individual audio files. The layout separates header, format, and sample-data chunks and can point to an ID3v2 tag at the end, making track metadata practical for music libraries.¹

DSF is distinct from Philips' earlier DSDIFF container. Both can hold DSD, but DSDIFF commonly uses .dff, starts with FRM8, and has a different chunk structure. Support for one does not guarantee support for the other.⁵

Working with .dsf and alternatives

Converting DSD to PCM changes the sample representation and requires filtering, so it is not bit-preserving. Choose the destination around the next task:

FFmpeg can create a basic FLAC copy with ffmpeg -i input.dsf output.flac. For production conversion, choose the PCM sample rate, bit depth, and low-pass filtering deliberately. Keep the original because converting back to DSF cannot reconstruct the original one-bit stream.