HTK to SMP Converter

Convert research HTK recordings to SMP

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Cross-Format Audio

Convert academic HTK audio to SMP — hardware sampler format accessible on modern platforms and devices.

No Install Needed

No downloads or plugins required. Convert HTK to SMP directly in your web browser on any device.

Fast Conversion

Lightweight source files mean near-instant conversion. Get your SMP output in seconds, not minutes.

How to convert HTK to SMP

1

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

2

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

3

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

About formats

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
SMP is the native file format of SampleVision, a sample editing application developed by Turtle Beach Systems around 1990. SampleVision was among the first PC-based visual sample editors, letting musicians view waveforms on screen and perform cut, copy, paste, and loop-point editing — capabilities previously limited to expensive dedicated hardware samplers. The SMP format stores 16-bit mono PCM audio along with sampling-specific metadata: loop start and end points, sustain loops, release loops, and MIDI root note assignments. This made SMP files directly useful for creating and exchanging patches between hardware samplers via MIDI Sample Dump Standard (SDS) transfers, which SampleVision automated through its interface. A primary advantage was bridging the PC world with professional sampling hardware from Akai, E-mu, Ensoniq, and Roland — devices that had tiny screens and minimal editing tools. The format also supported common sample rates (22050, 44100 Hz) and brief text descriptions alongside audio data. Though Turtle Beach pivoted to gaming peripherals and SampleVision was discontinued, SMP files persist in vintage sample library archives and can be converted using SoX.
Initial release: 1990

Frequently Asked Questions

Why convert HTK to SMP?

HTK is limited to speech research tools. SMP provides hardware sampler format that works with standard media players and applications.

What applications open SMP files?

SOX and SampleVision software can handle SMP files. Most are available as free downloads for major operating systems.

How is the SMP audio quality?

SMP provides good quality at standard settings. The output clarity depends on the original HTK recording quality.

How fast is the conversion?

Both formats produce manageable file sizes. The HTK to SMP conversion finishes almost instantly on our infrastructure.

Are my files kept private?

Uploaded HTK files are deleted immediately after conversion. SMP results are automatically erased from our servers within 24 hours.