HEVC to NIST Converter

Extract NIST Sphere audio from HEVC video online

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Research Standard

NIST is the government standard for speech data — extracting from HEVC produces research-grade audio.

Fast Extraction

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

Secure Files

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

How to convert HEVC to NIST

1

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

2

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

3

Let the file convert and you can download your nist 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
NIST SPHERE (SPeech HEader REsources) is a specialized audio file format created by the National Institute of Standards and Technology for speech research, particularly projects funded by DARPA. The format wraps raw audio samples with a structured ASCII header encoding metadata such as sample rate, channel count, encoding type, speaker demographics, and transcription annotations — making it ideal for distributing speech corpora. NIST files typically store uncompressed PCM or mu-law audio at telephone-quality sample rates (8 kHz or 16 kHz), though the container is flexible enough to hold various encodings. A key advantage is the rich self-documenting header that lets researchers embed detailed corpus metadata directly in the file, eliminating sidecar files. SPHERE has also become the de facto standard for major speech databases like TIMIT, Switchboard, and the Fisher corpus, ensuring broad recognition across academic and government labs. The open specification and availability of command-line tools (sphere, h_strip, w_decode) make it straightforward to convert, inspect, and process these files programmatically in speech processing pipelines.
Initial release: 1990

Frequently Asked Questions

Why convert HEVC to NIST?

NIST Sphere is the government standard for speech data interchange.

How do I open NIST files?

NIST speech tools, SoX, Kaldi, and HTK.

Is only the audio extracted?

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

Can I convert multiple files?

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

Are my uploads secure?

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