HEVC to CVSD Converter

Get CVSD audio from HEVC video quickly

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Secure Voice

CVSD serves military and Bluetooth voice — extracting from HEVC creates audio for secure communications.

Fast Extraction

Audio extraction skips video processing — your HEVC-to-CVSD conversion finishes in seconds, not minutes.

Secure Files

HEVC uploads are erased immediately after conversion. CVSD outputs are deleted within 24 hours.

How to convert HEVC to CVSD

1

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

2

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

3

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

About formats

HEVC (High Efficiency Video Coding), also designated as H.265 and MPEG-H Part 2, is a video compression standard developed jointly by the ITU-T Video Coding Experts Group and the ISO/IEC Moving Picture Experts Group. Approved in January 2013, HEVC was designed as the successor to H.264/AVC with the primary goal of doubling the compression efficiency — achieving equivalent visual quality at roughly half the bit rate. The standard accomplishes this through larger coding tree units of up to 64x64 pixels, more sophisticated motion prediction with 35 directional intra modes, advanced sample adaptive offset filtering, and parallel processing tools including tiles and wavefront parallel processing. HEVC supports resolutions from 320x240 up to 8192x4320 (8K UHD), making it future-proof for emerging display technologies. The codec is widely adopted in broadcasting, where it enables efficient delivery of 4K and HDR content over bandwidth-constrained channels, as well as in video conferencing and surveillance applications. Apple adopted HEVC as the default recording format for iOS devices beginning with iOS 11, dramatically expanding its consumer reach. Despite technical superiority over H.264, a complex and fragmented patent licensing landscape has driven interest in royalty-free alternatives like AV1, though HEVC remains deeply embedded in broadcast infrastructure and consumer electronics worldwide.
Initial release: January 25, 2013
CVSD (Continuously Variable Slope Delta modulation) is a voice digitization method standardized for military and telephony use by NATO and the CCITT during the 1970s. It encodes differences between consecutive samples as a single bit — 1 if the current sample exceeds the prediction, 0 otherwise — while a syllabic companding filter adjusts step size by monitoring runs of identical bits. Operating at 16 to 64 kbps, CVSD balances voice intelligibility against bandwidth, making it the encoding of choice for secure military links and tactical radio systems. The bitstream can be decoded with straightforward hardware, originally built into dedicated integrated circuits. One advantage is implementation simplicity — encoders and decoders need minimal resources, enabling real-time processing on low-power embedded hardware. Robustness under noisy conditions is another strength, as single-bit errors affect only local samples rather than corrupting entire frames. SoX provides software encoding and decoding support, letting modern systems work with legacy CVSD recordings from military archives and vintage telecommunications infrastructure.
Developer: CCITT / NATO
Initial release: 1970

Frequently Asked Questions

Why convert HEVC to CVSD?

CVSD is used in military radio, Bluetooth headsets, and secure voice communication.

How do I open CVSD files?

SoX, military radio, and Bluetooth audio tools handle CVSD.

Is only the audio extracted?

Yes — the video portion of the HEVC file is discarded. Only the audio track is saved as CVSD.

Can I convert multiple files?

Upload several HEVC videos at once and extract CVSD audio from each simultaneously in a single batch.

Are my uploads secure?

HEVC files are deleted immediately after conversion. CVSD outputs are removed from our servers within 24 hours.