CAVS to AV1 Converter

CAVS to AV1 Converter

A .cavs file is a raw Chinese AVS video elementary stream: picture only, with no container, no index and no soundtrack wrapped around it. AV1 is the opposite kind of object — a modern, royalty-free codec that current browsers, phones and editors decode natively. This page sets out what each format actually is, what the conversion carries across, and how to drive the encoder controls that appear on this tool.

CAVS (AVS1) at a Glance

AV1 at a Glance

How to Convert CAVS to AV1

1. Upload Your CAVS File: Drag the .cavs file onto the page or click "+ Add Files" to browse. Several raw AVS streams can be queued together and encoded with one set of settings.
2. Set the Quality Preset: Open Advanced Options and use the Preset dropdown under File Compression — it is preselected to "Very High (Recommended)". Lower presets shrink the file; "Highest" keeps the most detail out of an already-compressed broadcast source.
3. Choose a Resolution or Trim Range: Under Video resolution pick "Keep original", "Preset Resolutions", "Resolution Percentage" or an exact "Width x Height". Under Trim, switch from "Unchanged" to "Time Range" and set a start time and duration to encode only part of a long capture.
4. Convert and Download: Click "Convert" and take the AV1 file. No sign-up, no watermark.

What Comes Out: Container, Extension and Silence

Choosing AV1 names the output after the codec rather than the wrapper. The bytes you download are AV1 video inside a Matroska container, carrying a .av1 extension that many players and editors reject on sight because they route files by extension rather than by inspecting them. Renaming the file to .mkv changes nothing inside it and makes it open in VLC, mpv and most editors. If you would rather never deal with that, target CAVS to MKV or CAVS to MP4 instead — MP4 falls back to a widely supported codec that plays on hardware AV1 will never reach.

The silence is a property of the source, not of this converter. A bare AVS elementary stream never contained an audio track: in AVS broadcast workflows the sound was coded separately and muxed in only when the transport container was assembled. The Audio Codec list on this page (Opus, AAC, AC3, EAC3, DTS, FLAC, MP2, MP3, Vorbis) applies to sources that carry sound; with a raw .cavs there is nothing to hand it.

Frequently Asked Questions

What exactly is inside a .cavs file?

An AVS1-P2 video bitstream in the Jizhun base profile — the same coded-picture layer a Chinese digital-TV or IPTV device would feed straight to its decoder — with none of the container scaffolding that MP4 or MKV would add. There is no header describing duration, no seek index, no track list and no audio. That is exactly why general-purpose players fail on it: even a player that could decode AVS1 has nothing to tell it how to open the file.

Why does my AV1 output have no sound?

Because the input had none. The converter maps whatever streams it is given, and a raw .cavs supplies a single video stream. If your footage originally had a soundtrack, it lives in the container the .cavs was demuxed out of — convert that original file instead of the extracted elementary stream, and the audio comes with it.

Why is the file named .av1 instead of .mkv, and will anything play it?

The output is a Matroska file that has been given the codec's name as its extension. VLC, mpv and ffmpeg-based tools sniff the content and play it as-is; Windows Photos, QuickTime and most NLEs look at the extension first and refuse. Rename .av1 to .mkv — same bytes, no re-encode — and the compatibility problem disappears.

Is AV1 actually a good target for standard-definition broadcast footage?

It is efficient but not free. AV1's gains are largest on high-resolution, high-bitrate sources; on the standard-definition material that most .cavs captures contain, the absolute byte savings are smaller and the encode still costs real time. Pick AV1 when you want a small, royalty-free, future-proof archive copy. Pick an H.264 MP4 when you want the file to open instantly on a decade-old phone, TV or editor.

Which browsers and devices decode AV1 today?

Chrome from version 70, Firefox from 67, and Edge from 121 all decode AV1, with Safari listing partial support from 17.0 on Apple hardware that has an AV1 decoder — around 94% of tracked users on caniuse. Devices without a hardware decoder fall back to software decoding, which is CPU-hungry on long or high-resolution clips.

Will converting from CAVS to AV1 lose quality?

Yes, a little, and it is unavoidable. AVS1 and AV1 are both lossy codecs with different transform and prediction designs, so there is no way to carry the coded data across untouched — the server decodes every AVS frame and re-encodes it. Nothing here restores detail the broadcast encoder already discarded. Keeping the Preset at "Very High" or "Highest" and leaving the resolution at "Keep original" simply avoids throwing away more.

Which audio codec would AV1 use if my source did have sound?

An AV1 target defaults to Opus, which pairs naturally with a Matroska wrapper, and the dropdown also offers AAC, AC3, EAC3, DTS, FLAC, MP2, MP3 and Vorbis. On this page the setting is inert because the input is a silent elementary stream — it matters when you convert a real container such as an MP4, MKV or transport stream.

Can I convert an AV1 or MP4 file back into .cavs?

No, and not because of a policy choice: there is no production-grade AVS1-P2 encoder in the open-source toolchain, only decoders. AVS2 has an encoder (libxavs2), but that is a different, incompatible generation. CAVS is a read-only format in practice, which is why every AVS page here converts out of it and none convert into it.

How is my file handled while it is being converted?

It is uploaded over an encrypted connection, decoded and re-encoded on our servers, and deleted automatically a few hours later — no sign-up, no watermark, never shared or made public. The practical ceiling on a long broadcast capture is upload time and size, so use the Trim controls to send only the segment you need.