IETF Opus codec now ready for testing, That's CELT 0.11 Options

[jmvalin]

We'd like to announce that the Opus codec is now ready for testing. The bit-stream is now is a "pseudo-freeze", which means that unless a problem is found during testing/review, there are no longer any changes planned. The only exception to this are the SILK-mode FEC and the stereo SILK mode, which should be landing in the next few days. Considering that these are not critical features, we felt like the testing phase could already begin.

You can get the source code in two different ways. There is a release tarball at http://jmvalin.ca/opus/opus-0.9.0.tar.gz . You can also extract the source directly from the I-D ( http://www.ietf.org/id/draft-ietf-codec-opus-02.txt ) with the following command:

cat draft-ietf-codec-opus-02.txt | grep '^\ \ \ ###' |
sed 's/\s\s\s###//' | base64 -d > opus_source.tar.gz

Now the Opus codec supports three mores, one of which is identical to CELT 0.11, which was just released (not announced officially yet).

It would be nice if the HA community could help test this codec. Opus targets a very wide range of bit-rates, from 6 kb/s narrowband speech up to 510 kb/s stereo music. Perhaps a 64-96 kb/s stereo music test would be interesting to do. Anyone would like to help?

[polemon]

Can we have some updates about OPUS? there isn't much info on the opus-code.org page. In fact, it seems pretty stagnant. Maybe on a technology readiness level or something?

The last thing I've seen was the presentation about OPUS. I was looking through the IETF website (some links seem dead from the tread post), but even there seems to be close to no changes.

The only sign of changes and therefore activity, was the change date of this document: http://datatracker.ietf.org/doc/draft-ietf-codec-opus/
On the history table ( http://datatracker.ietf.org/doc/draft-ietf...c-opus/history/ ) it seems, the codec is somewhat in an idle state, waiting for approval from other departments.

The reason why I'm asking about updates, is because there is very little discussions going on about using OPUS being used as archiving codec. I know the codec is designed to be an interactive codec, for VoIP and the likes, but the presentation that I've been watching, suggested that it is also very capable of creating transparent results at lower bitrates than Vorbis is even AAC. So, does OPUS make sense as archiving codec for music collections? I haven't found any documents discussing this.

[NullC]

Can we have some updates about OPUS? there isn't much info on the opus-code.org page. In fact, it seems pretty stagnant. Maybe on a technology readiness level or something?
The last thing I've seen was the presentation about OPUS. I was looking through the IETF website (some links seem dead from the tread post), but even there seems to be close to no changes.
[...]
The reason why I'm asking about updates, is because there is very little discussions going on about using OPUS being used as archiving codec. I know the codec is designed to be an interactive codec, for VoIP and the likes, but the presentation that I've been watching, suggested that it is also very capable of creating transparent results at lower bitrates than Vorbis is even AAC. So, does OPUS make sense as archiving codec for music collections? I haven't found any documents discussing this.

First— You're aware of http://opus-codec.org/ Right?

You're correct that the main focus right now is on getting the standard published, so most commits are related to that.

There is an experimental branch with some pretty substantial (see posts above by IgorC) encoder perceptual enhancements— mostly serving the purpose of actually taking advantage of VBR... but other than fixing some regressions not a lot has happened with it lately. Right now the Xiph team is splitting resources between Opus and our new video codec work... and just shepherding the format through the IETF is itself a lot of work.

That said— file based usage is absolutely a priority for the time of the 1.0 release (which will happen along with publication of the standard). I've been spending time getting opus-tools, a set of simple command-line tools for encoding/decoding Opus in fixed files, ready for an initial official release— hopefully this coming weekend. I would _really_ appreciate testing and feedback, and if people need windows binaries made for testing, please let me know and I'd be glad to build some.

And the biggest news on this front is that we have support in Firefox, in the audio tag. It's only in the 'nightly' versions now and is preferences off and has a couple bugs, but it generally works great. This means that fairly rapidly after Opus' release the files will be playable on a significant fraction of desktop PCs— the browser is not exactly an ideal audio-player but compatibility is important..

There are a lot of things that need to be done (this list is far from inclusive) for the big 1.0 release, and if Opus interests you please come lend a hand (the easiest way to join in is via the IRC channel that you can reach through the Opus website).

This post has been edited by NullC: May 24 2012, 04:50

[NullC]

For any Windows users who are waiting on binaries to play around with Opus, I've prepared a binary build of opus-tools.
Feedback would be greatly appreciated. (I'm interested in if "opusdec.exe file.opus" plays audio on real windows systems, or if it only works in wine). I especially want to hear any bug reports or critical missing features.

https://people.xiph.org/~greg/opus-tools.zip

As we approach the official release I'll get automated builds setup for opus and the exp4 tuning branches.

If anyone is interested in building a GUI oggdrop style tool for encoding Opus, perhaps just a GUI front end on opusenc, I think it would be very useful to people— if it's portable to *nix I'll help out (at least with review and testing), but I don't have the time free to drive the development myself.

This post has been edited by NullC: May 28 2012, 01:23