Opus Audio Codec 1.2 Release Candidate 1 Arrives

[shmerl]

AFAIK MS has patents on Opus, and none on Vorbis.

And they (or rather Skype) released those patents for royalty free usage. So Opus is a free codec for all intents and purposes.

[pal666]

AFAIK MS has patents on Opus, and none on Vorbis. So if you have patents yourself and don't like MS you may still choose Vorbis.

utterly wrong. ms licenses opus patents for free, unless you engage on Opus-related patent litigation against any user of Opus. that is if you have opus patents and want to sue some user of opus, then you better don't use opus. but then nobody cares about you, motherfucker

[carewolf]

No one gives a fuck about surround sound. Two speakers, maybe a subwoofer. Anything else is pointless unless you are in a movie theater.

I know, but it is kind of sad. It is the last thing AAC and AC3 still have going for them that open source codecs have crushed.

[jmvalin]

It doesn't support compression between sources more than stereo, and most importantly, in multi-channel mode it doesn't actually say what ANY of the channels actually are, making it mostly pointless.


Note, this is the exact same issue vorbis and many other formats has, there are work-arounds to it, such as just accepting the poor compression of compressing every channel separately, and just make assumptions such as 6 channels being dolby 5+1, but it is just work-arounds.

(author of Opus here) I'm not sure where you're getting that information, but it's clearly incorrect. While Opus will not "jointly code" more than two channels, it has optimized psychoacoustic coupling of channels for surround setups up to 7.1, which you can see in this demo. As for Vorbis, it supports arbitrary multi-channel coupling, which you can see in this demo. Neither Vorbis nor Opus are limited in any way when it comes to surround. As surprising as it may sound, surround is actually easier to work with than stereo because loudspeakers are a lot more forgiving than headphones and surround headphones aren't actually very common (though they do exist!).

[jmvalin]

It doesn't support compression between sources more than stereo, and most importantly, in multi-channel mode it doesn't actually say what ANY of the channels actually are, making it mostly pointless.


Note, this is the exact same issue vorbis and many other formats has, there are work-arounds to it, such as just accepting the poor compression of compressing every channel separately, and just make assumptions such as 6 channels being dolby 5+1, but it is just work-arounds.

(author of Opus here) I'm not sure where you got that information, but it's incorrect. Opus will do "joint coding" of up to 2 channels, but actually has optimized psychoacoutic channel coupling for up to 7.1 channels (up to 255 in the format), as you can see in this demo. As for Vorbis, it has arbitrary multi-channel joint coding and also supports up to 7.1 in the current encoder and up to 255 in the format, as you can see in this other demo. As surprising as it may sound, surround is actually easier to deal with than stereo, since loudspeakers are a lot more forgiving of artefacts than headphones and somehow not many people use surround headphones (they do exist!).

[artyom.h31]

I know, but it is kind of sad. It is the last thing AAC and AC3 still have going for them that open source codecs have crushed.

I've tried to encode 6 channel audio and looks like channel mapping is preserved.

https://pastebin.com/5QRJs3iK

How can I check mapping if I don't have a 5.1 sound system?

[jmvalin]

I know, but it is kind of sad. It is the last thing AAC and AC3 still have going for them that open source codecs have crushed.

Actually, both Vorbis and Opus are *way* better at surround than AC3. I'm not aware of any formal comparison with AAC, but that's probably much closer. I made another post with more details about surround in Opus and Vorbis, but it's pending moderation because it includes URLs to demos about surround support for both of them. In any case, I'm not sure where the idea that Vorbis and Opus don't support surround come from, but they both have good support and know about channel positions and all.

[jmvalin]

I've tried to encode 6 channel audio and looks like channel mapping is preserved.
How can I check mapping if I don't have a 5.1 sound system?

Actually, both Vorbis and Opus are *way* better at surround than AC3. I'm not aware of any formal comparison with AAC, but that's probably much closer. I made another post with more details about surround in Opus and Vorbis, but it's pending moderation because it includes URLs to demos about surround support for both of them. In any case, I'm not sure where the idea that Vorbis and Opus don't support surround come from, but they both have good support and know about channel positions and all.

[andreano]

jmvalin

*respect* O_o

[Wilfred]

utterly wrong. ms licenses opus patents for free, unless you engage on Opus-related patent litigation against any user of Opus. that is if you have opus patents and want to sue some user of opus, then you better don't use opus. but then nobody cares about you, motherfucker

As I said, you need to trust MS. MS is the company which has been convicted for misuse of its monopoly in both the USA and the EU. I'm not a lawyer, but I'm not sure their license agreement does not have any loopholes. Again, it goes to trust, do you trust MS?