HEVC to HTK Converter

Pull HTK audio from HEVC footage online

Drop files here. 1 GB maximum file size or Sign Up
to
Facebook Amazon Microsoft Tesla Nestle Walmart L'Oreal

Speech Research

HTK is standard for speech research — extracting from HEVC prepares audio for acoustic model training.

Fast Extraction

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

Secure Files

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

How to convert HEVC to HTK

1

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

2

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

3

Let the file convert and you can download your htk 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
HTK is the native waveform container for the Hidden Markov Model Toolkit, a software suite developed at Cambridge University's Engineering Department for speech recognition research. First distributed in 1993, HTK rapidly became a reference platform in computational linguistics labs worldwide, and its file format followed suit. Each file stores a sequence of parameter vectors or raw samples prefixed by a 12-byte header specifying the number of frames, the frame period in 100 ns units, the byte count per frame, and a type code indicating the data kind — options range from waveform PCM to Mel-frequency cepstral coefficients and filter-bank energies. This versatility lets a single container carry both source audio and extracted features without changing parsers. The deliberately minimal header avoids alignment padding or optional chunks, making the format trivial to read from C, Python, or MATLAB with a few lines of binary I/O. Three advantages underpin HTK's lasting relevance: tight integration with the HTK training and recognition pipeline, deterministic byte layout that eliminates parser ambiguity, and widespread adoption in academic corpora.
Initial release: 1993

Frequently Asked Questions

Why convert HEVC to HTK?

HTK is used by the Hidden Markov Model Toolkit for speech recognition research.

How do I open HTK files?

HTK toolkit, Kaldi, and academic speech processing tools.

Is only the audio extracted?

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

Can I convert multiple files?

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

Are my uploads secure?

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