CAVS to WMV Converter

CAVS to WMV Converter

A .cavs file is a raw Chinese AVS (AVS1) video bitstream — China's home-grown coding standard, used mainly in domestic digital TV, IPTV, and set-top-box recordings. Outside that ecosystem almost nothing opens it directly. WMV (Windows Media Video) is Microsoft's video format, built to play in Windows Media Player and across the Windows tooling that legacy office and education pipelines still rely on. This converter decodes the orphaned AVS stream and re-encodes the picture into a WMV that Windows actually understands — and it is honest about one catch: a raw .cavs carries no audio, so the resulting WMV is silent because there was never any sound to carry. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public.

CAVS (Chinese AVS) Format at a Glance

WMV Format at a Glance

How to Convert CAVS to WMV

1. Upload Your CAVS File: Drag and drop your .cavs onto the page or click "+ Add Files" to browse from your computer. You can queue several raw streams and convert them with the same settings.
2. Set the Preset: Open Advanced Options. Under "File Compression" leave "Preset" on "Very High (Recommended)" for a near-source result, or switch to "Specific file size" to target an exact size in MB.
3. Set Resolution and Trim (Optional): Use the "Video resolution" presets or "Width x Height" to rescale; under "Show All Options" the "Video Codec" defaults to WMV 2 (you can switch to WMV 1). Use the "Trim" section's "Time Range" to export just the segment you need.
4. Convert and Download: Click "Convert" and download your WMV. No sign-up, no watermark.

For footage you want to play and keep efficient outside the Windows ecosystem, CAVS to MP4 re-wraps the picture as H.264 — far more compatible than either AVS or WMV — and the general Video Converter handles other legacy source formats.

Frequently Asked Questions

What exactly is a .cavs file?

It is a raw video elementary stream encoded with AVS1 (Audio Video Coding Standard), China's national video-coding standard, defined by GB/T 20090.2-2006. The picture is compressed with the AVS1-P2 JiZhun profile, which uses block-based motion compensation much like MPEG-2 and H.264. It is most common in Chinese digital-TV and set-top-box environments and rarely seen elsewhere, which is why general-purpose players usually can't open it.

Why does the converted WMV have no sound?

Because a raw .cavs file is an AVS1 video elementary stream — it carries no audio for the converter to copy or transcode. In Chinese AVS workflows the sound was encoded as a separate stream and muxed in only when the final container was built, so the bare .cavs on its own is mute. The WMV therefore comes out silent. If you have the original container (an MP4, MKV, or transport stream) that holds both the video and its audio, convert that file instead — the audio lives there, not in the demuxed .cavs.

Which video codec does the WMV output use?

This tool writes WMV 2 — the Windows Media Video 8-era codec — by default, which is the codec most broadly associated with .wmv files in Windows Media Player. Under "Show All Options" you can switch "Video Codec" to WMV 1 if a particular legacy tool needs it. Note that this is distinct from VC-1 (SMPTE 421M), the standardized descendant of WMV 9; the default here targets the older, widely decodable WMV codec for maximum compatibility with legacy Windows playback.

Will I lose quality converting CAVS to WMV?

Yes, some — and it is one-way. A .cavs stream is already lossily coded with AVS1, and WMV does not carry that codec, so the converter decodes the AVS1 frames and re-encodes them to WMV 2. That second compression pass discards some data and no setting recovers detail. Keep "Preset" on "Very High" and leave the native resolution so the re-encode has the most to work with; you can avoid throwing more away, but you can't add any back.

Is the AVS1 standard still relevant, or is CAVS obsolete?

AVS1 is dated — it was promulgated in 2006 — but it is not abandoned: the AVS family continued through AVS+ (2012) for HD broadcast and on to AVS2 and AVS3 for UHD. The original .cavs AVS1 streams persist in older Chinese broadcast and set-top-box archives. Both ends of this conversion are relatively niche today — a Chinese-broadcast AVS stream going into a legacy Microsoft codec — which is exactly why, if your goal is durable playback rather than a Windows-specific file, CAVS to MP4 is the more future-proof choice.

Is .cavs the same as a .avs AviSynth script?

No, and they are easy to confuse. A .cavs file is a raw AVS1 video bitstream — actual coded picture data from the Chinese AVS standard. A .avs file is an AviSynth script: a small text file of frameserving instructions, not video itself. This converter expects the video bitstream. If you uploaded an AviSynth script by mistake, there is no AVS1 picture inside it to wrap into WMV.

How are my files handled, and how long are they kept?

In our testing, re-encoding a short raw .cavs stream to WMV 2 at the "Very High" preset produced a clean Windows-playable file with no audio track, exactly as expected from a silent source. Your file is uploaded over an encrypted connection, decoded and re-encoded into WMV on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public. The realistic limit on very large broadcast captures is upload time, not anything on your device.