SHN to CVU Converter

Encode Shorten audio as CVU mu-law online

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Telephony Format

CVU serves telephony voice systems — lossless SHN gives clean speech input for the encoding process.

Server Encoding

Our servers handle SHN to CVU conversion — no telephony tools needed on your machine.

Secure Processing

SHN uploads are erased immediately. CVU results are purged within 24 hours.

How to convert SHN to CVU

1

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

2

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

3

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

About formats

Shorten (SHN) is a lossless audio compression codec created by Tony Robinson at SoftSound) and first published in 1993, making it one of the earliest practical lossless compressors. The algorithm uses linear prediction to estimate each sample from predecessors, then encodes residuals with Huffman or Golomb-Rice codes. Compression ratios typically fall between 2:1 and 3:1, with the guarantee that decoded output is bit-identical to the original. Shorten gained cultural significance in the late 1990s as the preferred format for trading live concert recordings online — communities like etree.org built entire distribution networks around SHN files, and bands like the Grateful Dead and Phish tacitly endorsed the practice. One advantage was the format's simplicity: encoding and decoding ran fast even on modest Pentium-era hardware. Another strength was deterministic output — the same input always produced the same bytes, making checksums reliable for verifying integrity across thousands of traders. While FLAC eventually superseded Shorten with better compression, seeking support, and embedded metadata, SHN retains historical importance and extensive live music archives in the format still circulate today.
Initial release: 1993
CVU is an unsigned variant of the CVS telephony audio format, differing in how delta-encoded values are represented in the binary stream. While CVS stores slope delta values as signed quantities, CVU treats them as unsigned, shifting the numerical interpretation of each sample. Both share the underlying CVSD modulation technique — 1-bit adaptive delta coding where step size varies according to recent output bit patterns — operating at comparable rates, typically 16 kbps for narrowband voice at 8 kHz. The signed-versus-unsigned distinction matters at the decoder, where correct interpretation determines proper waveform reconstruction. CVU files appear in telephony and embedded communication contexts where hardware adopted the unsigned convention. A practical advantage is straightforward interfacing with systems using unsigned arithmetic natively, avoiding sign extension in decoders. Like its signed counterpart, CVU achieves extreme bandwidth efficiency, compressing voice into compact bitstreams for constrained links. SoX supports CVU, providing a reliable path for converting these niche telephony recordings into modern formats for analysis or archival.
Developer: CCITT / ITU-T
Initial release: 1970

Frequently Asked Questions

What is CVU?

CVU is a specialized audio encoding used in telephony and voice processing applications.

Why convert SHN to CVU?

Telephony systems may require CVU audio. Lossless SHN provides clean voice recordings for accurate encoding.

What processes CVU?

SoX, telephony platforms, and voice processing development tools handle CVU format audio.

Is CVU for music?

No — CVU is designed for voice at telephony quality. Use MP3, FLAC, or AAC for music content.

Is it secure?

SHN uploads are deleted immediately. CVU results are removed within 24 hours.