CAVS to MP4 Converter

CAVS to MP4 Converter

A .cavs file holds a raw Chinese AVS video stream — China's home-grown alternative to MPEG-2 and H.264, used mainly in domestic digital TV, IPTV, and set-top-box recordings. Outside that ecosystem almost nothing plays it: no web browser decodes CAVS, and most consumer players choke on the extension. Converting to MP4 re-wraps the picture in an H.264 + AAC container that plays on practically every phone, browser, editor, and TV. 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

MP4 Format at a Glance

How to Convert CAVS to MP4

1. Upload Your CAVS File: Drag and drop your .cavs file onto the page or click "+ Add Files" to select it from your device. You can queue several files and convert them with the same settings.
2. Pick a Quality Preset: Leave the Preset on "Very High (Recommended)" to stay close to the source, or open Advanced Options to switch the Video Codec between H.264 and H.265, set a Specific file size, or choose Constant Bitrate / Variable Bitrate.
3. Resize or Trim (Optional): Use Resolution Percentage or Preset Resolutions to scale the picture, set an exact Width x Height, or set a Time Range under Trim to export just part of the clip.
4. Convert and Download: Click "Convert" and download your MP4. No sign-up, no watermark.

Have several legacy clips to modernise? The general Video Converter handles other source formats, AVI to MP4 covers another older container, and once you have the MP4 you can shrink it further with Compress MP4.

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.

Will I lose quality converting CAVS to MP4?

Any re-encode from one lossy codec to another (here, AVS1 to H.264/H.265) discards some data, but at the "Very High" preset the loss is hard to spot for normal viewing. If you want to minimise generational loss, raise the bitrate or pick a Specific file size that is at or above the source size rather than letting it shrink — you can't add detail back, but you can avoid throwing more away.

Why does my media player refuse to open the .cavs file directly?

CAVS never achieved broad player support outside China's AVS ecosystem, and no web browser decodes it natively. Most desktop players rely on FFmpeg's cavs decoder under the hood, and many consumer apps simply don't bundle it. Converting to MP4 (H.264) sidesteps the problem because H.264-in-MP4 plays in Chrome, Firefox, Edge, Safari, and essentially every hardware player.

Does this output AVS2 or AVS3 instead of MP4?

No. AVS2 (IEEE 1857.4) and AVS3 are later generations of the Chinese standard aimed at 4K/UHD, but this tool converts your AVS1 .cavs source into a standard MP4 (MPEG-4 Part 14) using H.264 or H.265 — the formats with universal device and browser support. The goal here is compatibility, not staying inside the AVS family.

Which video codec should I choose for the MP4 — H.264 or H.265?

Pick H.264 for maximum compatibility: it plays everywhere, including older TVs, browsers, and editing software. Pick H.265 (HEVC) if you want a smaller file at similar quality and you know your target devices support it — HEVC roughly halves the bitrate of H.264 for comparable quality but isn't as universally decodable. When in doubt, keep H.264, the MP4 default here.

Can I convert just a section of the CAVS recording?

Yes. Open the Trim section, switch from "Unchanged" to Time Range, and set the start and duration. This is handy for set-top-box captures that bundle a whole broadcast block — you can export only the segment you actually want instead of the full recording.

How long do you keep my uploaded file?

Your .cavs upload and the resulting MP4 are processed on our servers and deleted automatically a few hours after conversion. No account is required, there's no watermark, and files are never shared or made public. The realistic limit on very large broadcast captures is upload time, not anything on your device.

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, which is exactly why converting them to MP4 is the practical way to keep that footage playable on modern hardware.