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Opus 1.1 alpha version (not BABYEATER), [split from the good old megathread]
IgorC
post Feb 10 2013, 02:00
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If somebody hasn't seen there is an official Opus 1.1 alpha.

https://ftp.mozilla.org/pub/mozilla.org/opu...alpha-win32.zip

Also some kinda settings to play with
https://wiki.xiph.org/Opus_tuning
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jensend
post Feb 15 2013, 00:02
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Plenty of people ready to ream the guy with knee-jerk responses to seeing spectrograms, but only lvqcl gives any indication of having downloaded and examined anything.

There's normally good reason to expect that feeding an encoder a basically constant signal will result in basically constant output, and finding something else might lead one to think there's a bug. Of course spectrograms are not a quality measure, but the spectrograms are perfectly legitimate as a way of showing at a glance that his reasonable expectation of near-constancy has been completely upset in the case of his test samples. You can verify that by downloading his 7z and doing a bunch of listening but he's tried to help people be able to see this more easily and quickly. That didn't get communicated as well as one might have hoped, since we didn't know the nature of his test signals and his little b/w log(f) spectrograms

Right now, those of us who are just a little more familiar with Opus don't have that expectation. The pre-1.1 encoder changes a lot of parameters- certainly including mode and bandwidth - to adapt to its input. Because encoder work thus far has been aimed largely at real-time uses, there's very little encoder lookahead; it's just looking at the current frame and its past analysis. Thus the encoder may encode at non-optimal settings for a little while before it settles on better parameters.

Apparently the encoder starts off with parameters that are too optimistic for these signals, and has those parameters confirmed by the simplicity of encoding the initial silence. When the fade-in hits it starts hunting around for a new mode and bandwidth to try to preserve less of the audio but do a better job with what it does preserve. In the 32-40kbps one there's a very audible glitchy click, probably as it's switching from an MDCT mode to hybrid mode. I can't reproduce the click on the 1.1a build I have, though it does waffle between different modes and show other interesting behaviors.
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- IgorC   Opus 1.1 alpha version (not BABYEATER)   Feb 10 2013, 02:00
- - Seren   QUOTE (IgorC @ Feb 10 2013, 09:00) If som...   Feb 10 2013, 10:53
- - moosehunter   I compiled opus-tools with libopus 1.1-alpha using...   Feb 13 2013, 04:54
- - LithosZA   QUOTE I compiled opus-tools with libopus 1.1-alpha...   Feb 13 2013, 06:39
- - Jplus   Since eig is known to be a hard sample it shouldn...   Feb 13 2013, 10:05
- - Banned   And what are these graphs supposed to show? Why do...   Feb 14 2013, 07:19
|- - softrunner   QUOTE (Banned @ Feb 14 2013, 10:19) And w...   Feb 14 2013, 09:15
|- - saratoga   QUOTE (softrunner @ Feb 14 2013, 03:15) Q...   Feb 14 2013, 20:16
|- - db1989   QUOTE (saratoga @ Feb 14 2013, 19:16) QUO...   Feb 14 2013, 20:25
- - jensend   Plenty of people ready to ream the guy with knee-j...   Feb 15 2013, 00:02
|- - db1989   QUOTE (jensend @ Feb 14 2013, 23:02) Plen...   Feb 15 2013, 16:39
- - softrunner   QUOTE (saratoga @ Feb 14 2013, 23:16) Spe...   Feb 16 2013, 02:11
|- - db1989   QUOTE (softrunner @ Feb 16 2013, 01:11) D...   Feb 16 2013, 03:48
- - IgorC   After performing some blind tests on Opus 1.1a and...   Feb 23 2013, 19:12
- - CoRoNe   Although I'm no expert in detecting audible di...   Feb 23 2013, 23:06
- - CoRoNe   I didn't think my post would fit in either of ...   Feb 23 2013, 23:51
- - IgorC   A single result for sample http://www.rarewares.or...   Mar 14 2013, 03:14
|- - jmvalin   QUOTE (IgorC @ Mar 13 2013, 22:14) A sing...   Mar 14 2013, 21:41
- - mzso   Is it normal to get weird gap/crackly artifacts at...   Mar 14 2013, 20:32
|- - IgorC   QUOTE (mzso @ Mar 14 2013, 16:32) Is it n...   Mar 15 2013, 03:59
|- - mzso   QUOTE (IgorC @ Mar 15 2013, 04:59) QUOTE ...   Mar 15 2013, 09:45
- - IgorC   The noise is constant during the whole tonal part ...   Mar 15 2013, 03:37
|- - jmvalin   QUOTE (IgorC @ Mar 14 2013, 22:37) The no...   Mar 16 2013, 00:37
- - IgorC   OK. And yes, You're right. This isn't a ...   Mar 16 2013, 02:28
|- - jmvalin   QUOTE (IgorC @ Mar 15 2013, 21:28) Also t...   Mar 16 2013, 02:50
- - IgorC   It behaves exactly the same. Both beginnings have ...   Mar 16 2013, 03:05
|- - jmvalin   QUOTE (IgorC @ Mar 15 2013, 22:05) It beh...   Mar 16 2013, 03:35
- - IgorC   No hurry at all. If it will be improved at some po...   Mar 16 2013, 03:56
- - darkbyte   I wonder if there's any new builds we can try....   Apr 1 2013, 18:10
|- - lithoc   QUOTE (darkbyte @ Apr 2 2013, 01:10) I wo...   Apr 2 2013, 06:33
- - eahm   Every codec knows how to trick our earing, don...   Apr 2 2013, 06:42
- - wswartzendruber   I'm sitting here telling myself that Google Mu...   Apr 6 2013, 03:46
- - Mach-X   Coffee. Oh and as long as Starbucks coffee exists,...   Apr 6 2013, 04:20
- - softrunner   As I wrote before, Opus 1.1 alpha has some bugs, t...   Apr 7 2013, 23:11
|- - saratoga   QUOTE (softrunner @ Apr 7 2013, 17:11) Wh...   Apr 7 2013, 23:15
|- - jmvalin   QUOTE (softrunner @ Apr 7 2013, 18:11) Fo...   Apr 8 2013, 03:01
- - softrunner   QUOTE (saratoga @ Apr 8 2013, 02:15) Sure...   Apr 7 2013, 23:19
|- - saratoga   QUOTE (softrunner @ Apr 7 2013, 17:19) QU...   Apr 8 2013, 00:35
- - Gainless   Ok, so here's another ABXable issue with tonal...   Apr 8 2013, 20:36
- - Gainless   I've played a bit around with different frames...   May 6 2013, 17:13


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