Interesting Graph on the Mozilla forum
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| Author | Content |
|---|---|
| Bob_Robertson Sep 13, 2012 8:58 AM EDT |
https://hacks.mozilla.org/2012/09/its-opus-it-rocks-and-now-... The Mozilla.org posting as a very interesting graph. I was aware that G711, for example, was fixed rate, but it's fascinating to see that Vorbis has a very high floor bitrate, and that sort of thing. But then, it's also showing MP3 as having a very high floor in terms of minimum bitrate. Maybe the graph has been truncated more for "indication" than pure accuracy. Hmmmm. |
| CFWhitman Sep 13, 2012 9:53 AM EDT |
Does this mean I'll eventually be re-ripping all my CDs as Opus files rather than ogg vorbis files? By what I can dig up, that looks quite possible. Of course, I'll have to wait until Opus decoding is added to all my normally used software and hardware (firmware). I suppose that will mean Rockbox on my old Cowon D2, since I doubt Cowon will release an update that includes Opus for a player that old. Well, it's probably a couple of years off before that becomes practical in any case (although the uptake of this new format in software is nothing short of amazing by the information I'm finding on the Web). Edited for clarification. |
| vagabondo Sep 13, 2012 10:01 AM EDT |
If you mean by "floor bitrate" the minimum transmission rate for any of the codecs, that is not what the graph is for. It shows the results of experimentally measuring perceived sound quality at the measured bitrates. They were looking at expected usage for speech/telephony and music. I thought that the AMR licences changed to BSD, and if not there is openAMR. I would have been interested to see results for G.729, and an comparison of CPU loads. The plus for Opus is that it is a one-stop-shop, the execution parameters are simple, and that it works with today's browsers. There are examples at: http://opus-codec.org/examples/ |
| Bob_Robertson Sep 13, 2012 10:05 AM EDT |
Thanks, Vagabondo, that confirms my second theory, that the graph was illustrative, not technical. Oh well, until my car stereo can play Opus files, I'll just keep trying to fly under the MPAA's radar. Personal use, and all that. |
| vagabondo Sep 13, 2012 10:10 AM EDT |
> ogg vorbis files as Opus files
Not a lot of point unless you want to go for a lower bit-rate (sound quality and file size). They would actually be Ogg-Opus as the opus-tools use the ogg wrapper. I tried briefly it yesterday, and found both opus and opus-tools very straightforward to compile and use. |
| CFWhitman Sep 13, 2012 10:52 AM EDT |
Yes, I realized that Opus fell under the ogg umbrella. It's just that I tend to try to keep some consistency, and I suspect that Opus may become the more prevalent format in the future. So ripping my music to Opus won't be a priority, but I suspect I'll end up doing it eventually (I wonder how long before ruby-ripper supports Opus? I'm assuming that Opus files have full tag support, including normalization tags.) |
| DrDubious Sep 13, 2012 12:08 PM EDT |
Opus seems likely to take off. So far it really does look like it gives top-quality results for all major use cases besides extreme low bitrates (i.e. less than 9600-baud-modem speeds) and applications that require lossless compression, so there's no technical compromise required in exchange for the freedom as there arguably has been for, say, the Theora or VP8 video codecs, and you don't have to switch between two different codecs for Voice-over-IP and Music as you do with Speex and Vorbis (for example). Also unlike Theora video, the Opus audio codec seems to have hit official non-Alpha/beta 1.0+ release very quickly, and already has substantial corporate backing (Even Microsoft, or at least their Skype division), is already an accepted official standard, and seems to be going into quite a lot of projects pretty quickly. Vorbis is also high quality audio (definitely beats mp3) and support for it is actually a lot broader than it gets credit for, so it'll be a while before I stop using it, but I actually will be re-ripping my CDs to Opus and generating "OpusCasts" for web use in the near future nonetheless. I'm still trying to figure out how the heck a friggin' audio codec is turning me into an almost Apple-level fanboy for it... |
| caitlyn Sep 13, 2012 1:22 PM EDT |
Let's say Opus, from a technical standpoint, really is the be-all and end-all of audio codecs. Wonderful. "Likely to take off"??? If I see Opus players in stores successfully competing with iPods and other MP3 players I'll be the first to cheer to success of an Open codec. I just don't see it happening. Please, please, please tell me how this is really going to take off. I would love to know. Technical superiority have never translated into success in the marketplace. That's a sad fact but it remains a fact. |
| CFWhitman Sep 13, 2012 5:01 PM EDT |
I'm not sure that's what DrDubious meant. If a lot of high profile software supports Opus, and it is supported by high end hardware music players, then it will be successful enough. Really, it may not be obvious, but vorbis is a pretty successful codec. Pretty much all of the top end music players support it (there are no iPods that are top end - the closest is the Classic, which at least has decent digital to audio conversion, which is more than I can say for the other iPods). Opus is getting a lot more initial interest and support from a wider range of applications than vorbis did. Yet vorbis was successful enough for me to have no problem having all my music in vorbis format. It works on the software and hardware that is worth using, whether the "eighty percent" has any idea it exists or not. (Edit: When I say "all" my music in vorbis format, I just mean all the rips I have created myself. There's no upside to converting music from one lossy format to another, so some music that I happen to have acquired in mp3 format for one reason or another stays in mp3 format, unless I have to edit and re-encode it for some reason. Also, when I want lossless I use FLAC of course.) |
| caitlyn Sep 13, 2012 9:43 PM EDT |
CFWhitman: FLAC is actually my codec of choice. That's what I rip to. With really monsterously large hard drives dirt cheap nowadays I don't see the point of using any lossy codecs except for use in a portable player. There, sadly, I still use MP3 because I couldn't find one with the features I wanted that supported either Ogg-Vorbis or FLAC.
Quoting: high end hardware music players, then it will be successful enough.Now you've peaked my interest. I am really out of touch, I guess. High end hardware music players? Links to info would be very much appreciated. |
| DrDubious Sep 14, 2012 9:00 AM EDT |
Opus' main "advertising" has been for Voice-over-IP applications, for which it also is excellent (very low latency, apparently low CPU demand considering the quality), and I would expect it to start showing up in a lot of smartphone hardware for THAT purpose. Once the codec in in there, there's no reason not to also use it for "music" (and other not-just-speech audio). I can now report that I already have a portable music player with Opus support (the current nightly build of VLC for Android seems to be working perfectly on at least two of my Android devices now and plays Opus-encoded music just fine). Microsoft (via Skype) is on board with it (recently reported WebRTC "monkeywrench" seems to be more about low-level vs. high-level stuff that they want crammed into the standard, and possibly about the video codec, but NOT about Opus audio, which it sounds like they're still committed to), Asterisk is adding support, Cisco is reportedly supporting it (I'm assuming for VoIP), from the chromium bug tracker it looks like support for Opus will be coming to Chrom(e|ium) browser as well and seems very likely to hit Android officially as a core supported codec (though admittedly here Google is keeping infamously silent as always). Opus has enough going for it technically that it's not merely "a slightly better mp3 that's 'free'" (it IS a "much better mp3 that's free", but that's not all). Vorbis took a long time to gain traction but it has, and it doesn't even hit as many needs as Opus does - RIGHT NOW there seems to be major interest in VoIP and "cloud" streaming media, and as far as I can tell Opus beats both free and proprietary codecs for both at the same time - you don't need "special proprietary codec for low-bandwidth VoIP" and a separate one for "high-quality music", which I assume makes both licensing (free!) and implementation easier for integrators and developers. And I STILL DON'T KNOW why I'm so freaking worked up about it - I mean, I know why I like it, but the whole "wild-eyed fanboy/missionary" schtick I seem to have going on around the codec is not normal for me... |
| gus3 Sep 14, 2012 2:04 PM EDT |
@caitlyn, using FLAC on a portable player puts a double-whammy on the battery. The CPU cranks harder to restore quality, plus reading from storage more often due to less audio stream stored per filesystem block. (This latter point is equally true for lower-compression MP3 and Vorbis). FLAC doesn't really make sense for a battery-powered player. |
| CFWhitman Sep 14, 2012 2:58 PM EDT |
I should explain that when I say high end music players, I mostly mean music players with high sound quality. In that sense, even the lowly Sansa Clip Zip is a high end player (though the reliability rate for these players doesn't seem so great - when one works for the first couple of months it generally works for a long time, but some fail right away for some reason - fortunately, that means that the ones that fail usually fail under warranty). Then there are players like the Cowon J3 (recently discontinued, apparently) and my older Cowon D2. Other players with good sound quality of various prices include the Samsung P3 and the Samsung YP-R0. Generally, most Cowon players, newer Sansa players, as well as Samsung and better Sony players are better sounding players and they all include support for Vorbis and FLAC. With music/mp3 players, to me, sound quality is paramount, so that's the guide I generally go by when talking about what's better and worse (I'm sorry if I gave the impression I was talking about something more exotic). Some people have different priorities and are willing to use a player with mediocre sound quality and other features they want. Witness the success of the iPod even though the Classic is the only one with decent sound quality, and the whole line was expensive for a long time (not quite as much so recently). Of course, as far as I know, all Android devices support Vorbis out of the box (I believe FLAC as well, though I've never put FLAC files on an Android device), so at this point, that means really a lot of devices support Vorbis. Of course, any player for which a Rockbox build is available will also support Vorbis and FLAC if you use Rockbox. Rockbox has some other nice features as well, and is currently in development as an app for Android. @DrDubious: I have a nightly VLC build on a couple of Android devices, so apparently I'm already sporting Opus support without realizing it. I tend to use other devices for playing music most of the time though. |
| BernardSwiss Sep 14, 2012 7:42 PM EDT |
This discussion thread is practically an article on it's own -- and a pretty good one, too. I've certainly found it quite informative. |
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