MPEG-2 to NIST Converter

Extract NIST Sphere audio from MPEG-2 video online

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Research Standard

NIST is the government standard for speech data — extracting from MPEG-2 produces research-grade audio.

Fast Extraction

Audio extraction skips video processing — your MPEG-2-to-NIST conversion finishes in seconds, not minutes.

Secure Files

MPEG-2 uploads are erased immediately after conversion. NIST outputs are deleted within 24 hours.

How to convert MPEG-2 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

MPEG-2 is a widely deployed video and audio compression standard developed by the Moving Picture Experts Group and approved in 1995 as ISO/IEC 13818. Building on the foundations of MPEG-1, MPEG-2 was designed to handle higher bit rates and resolutions, particularly interlaced video for broadcast television, making it suitable for applications ranging from standard-definition TV to high-definition content. The standard introduces the concept of profiles and levels, allowing implementations to target specific capability tiers — from the Simple Profile for basic applications to the High Profile supporting 4:2:2 chroma for professional broadcast. MPEG-2 became the compression backbone of digital television worldwide, adopted by DVB, ATSC, and ISDB standards, and it serves as the video codec for DVD-Video, bringing movie-quality video to the consumer market. The transport stream layer provides robust multiplexing with error resilience features essential for broadcast delivery over noisy channels, while the program stream variant serves storage-oriented applications like DVDs. MPEG-2 supports resolutions up to 1920x1152 in the Main Profile at High Level, with bit rates reaching 80 Mbps in professional configurations. Although newer codecs like H.264 and HEVC offer substantially better compression efficiency, MPEG-2 remains entrenched in broadcast infrastructure, cable and satellite systems, and billions of DVD discs in circulation worldwide.
Initial release: 1995
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 MPEG-2 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 MPEG-2 file is discarded. Only the audio track is saved as NIST.

Can I convert multiple files?

Upload several MPEG-2 videos at once and extract NIST audio from each simultaneously in a single batch.

Are my uploads secure?

MPEG-2 files are deleted immediately after conversion. NIST outputs are removed from our servers within 24 hours.