M4V to SPH Converter
Extract M4V audio as NIST SPHERE speech format online
Video to Speech Data
Extract dialogue from Apple M4V videos and package it as NIST SPHERE — ready for speech recognition research and training datasets.
NIST Standard
SPH output follows the SPHERE specification exactly. Compatible with all major speech recognition frameworks used in academic research.
Any Platform
Convert M4V to SPH from any device with a browser — Windows, Mac, Linux, or mobile. No platform-specific tools required.
How to convert M4V to SPH
Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.
Choose sph or any other format you need as a result (more than 200 formats supported)
Let the file convert and you can download your sph file right afterwards
About formats
Frequently Asked Questions
SPH is the NIST standard for speech audio research. Extracting M4V dialogue into SPH makes Apple video content usable for ASR training.
Kaldi, HTK, Praat, and the NIST SPHERE toolkit all work with SPH natively. This format is standard across speech research institutions.
No — SPH stores PCM data without lossy compression. M4V audio reaches the SPHERE format with full quality for accurate analysis.
DRM-protected M4V from iTunes cannot be processed. Unprotected M4V files — screen recordings, personal videos — convert to SPH fine.
Yes — upload multiple M4V files and convert them all to SPH simultaneously. Great for assembling speech datasets from video collections.