CAVS to SPH Converter

Extract audio from CAVS and save as SPH online for free

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Audio Extraction

The converter pulls the audio track from CAVS and delivers a clean SPH file — stripping away the video data you do not need.

No Account Required

Start converting immediately — no registration needed for basic use. Create an account only if you want extended features.

Data Protection

Your files are handled securely — originals are erased immediately after conversion and outputs are auto-deleted within 24 hours.

How to convert CAVS to SPH

1

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

2

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

3

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

About formats

CAVS (Chinese Audio Video Standard) is a video compression standard developed by the Audio Video Coding Standard Workgroup of China and adopted as a national standard (GB/T 20090.2) in February 2006. The project began in 2002 with the aim of creating an independent compression technology that could serve the massive broadcasting and multimedia infrastructure in China without relying on foreign-licensed codecs. CAVS, also referred to as AVS1, achieves compression efficiency comparable to H.264/AVC while utilizing a simpler patent framework with significantly lower licensing costs. The standard supports video resolutions from standard definition up to high definition, making it suitable for both terrestrial digital television broadcasting and broadband streaming. Key technical features include 8x8 block transforms, multiple prediction modes, and a loop filter designed to reduce blocking artifacts at low bit rates. The Chinese government endorsed CAVS as the mandatory compression standard for the national digital TV broadcasting system, ensuring broad deployment across set-top boxes and television receivers in the country. While CAVS has limited international adoption compared to H.264 or HEVC, its significance lies in serving one of the largest media markets in the world and demonstrating a viable national alternative to globally dominant video coding standards.
Initial release: February 2006
SPH is the file extension for audio stored in the NIST SPHERE (SPeech HEader REsources) format, a standard created by the U.S. National Institute of Standards and Technology around 1990. Built for speech research, SPH files carry a 1024-byte ASCII header packed with metadata — database identifiers, channel counts, sample rates, byte ordering, and compression type — making every recording self-describing. The underlying audio is typically 16-bit linear PCM sampled at 16 kHz, though other configurations are permitted. Researchers at NIST, DARPA, and universities worldwide rely on SPH for distributing speech corpora such as TIMIT, Switchboard, and the LDC collections that underpin modern automatic speech recognition systems. A key advantage is that the human-readable header lets scripts parse recording metadata without binary decoding. The format's strict standardization also eliminates ambiguity when sharing datasets across institutions and platforms. Because SPH files store uncompressed PCM, they preserve full audio fidelity — critical when training acoustic models where even small artifacts can skew results.
Initial release: 1990

Frequently Asked Questions

Why convert CAVS to SPH?

If you only need the audio from a CAVS recording, converting to SPH strips the video and produces a lightweight audio file.

What program opens SPH files?

NIST speech tools and linguistic research applications process SPHERE audio files.

Do I need to install anything?

Not at all. The converter runs in your web browser — no downloads, plugins, or desktop applications are required for the conversion.

Does it work on phones and tablets?

Yes. The converter runs in any modern mobile browser on iOS and Android devices, with the same functionality as desktop.

What happens to my uploaded files?

Uploaded CAVS files are deleted from our servers immediately after processing. Converted SPH files are auto-removed within 24 hours.