Hydrogenaudio Forums

Lossy Audio Compression => Opus => Topic started by: IgorC on 2018-01-24 16:45:53

Poll
Question: What is the bitrate of your Opus files?
Option 1: 16 kbps or less votes: 3
Option 2: 24 kbps votes: 0
Option 3: 32 kbps votes: 1
Option 4: 48 kbps votes: 6
Option 5: 64 kbps votes: 15
Option 6: 80 kbps votes: 14
Option 7: 96 kbps votes: 28
Option 8: 112 kbps votes: 6
Option 9: 128 kbps votes: 47
Option 10: 145 kbps votes: 3
Option 11: 160 kbps votes: 26
Option 12: 175 kbps votes: 3
Option 13: 192 kbps votes: 12
Option 14: 224 kbps votes: 2
Option 15: 256 kbps votes: 10
Option 16: 280 kbps votes: 0
Option 17: 320 kbps votes: 3
Option 18: 350 kbps votes: 0
Option 19: More than 350 kbps votes: 3
Title: What is the bitrate of your Opus files?
Post by: IgorC on 2018-01-24 16:45:53
What is the bitrate of your Opus files?

There is related topic Point of transparency of Opus (https://hydrogenaud.io/index.php/topic,114656.0.html)
Title: Re: What is the bitrate of your Opus files?
Post by: finphil on 2018-01-24 18:06:20
Well, I have answered in terms of the bitrate I use in conversion from flac. This bitrate is not the same as my opinion of transparency, which is another topic ;D
Title: Re: What is the bitrate of your Opus files?
Post by: includemeout on 2018-01-24 19:05:33
Thanks to my ancient, dull Moto X phone not having a meagre SD card slot, ~85kpbs opus has consequently become the defacto choice for a more-than-conservative onus on my storage space for the dozen or so (mostly rock) albums I happen to listen to whilst on my (not-quite-daily) walks - with nothing to report home regarding my noticing any discernible artifact in the noisy, urban conditions I usually walk under - so much so that I didn't even bother carrying out any blind test.
Title: Re: What is the bitrate of your Opus files?
Post by: adamOLC on 2018-01-24 20:33:27
90% are 128 VBR.  The other 10% are 160 VBR.  I listen to heavy metal and black metal in particular tends to have artifacts at 128.  The music is very fast in general, but for some reason artifacts more than other genres of metal so I bump it up to 160.
Title: Re: What is the bitrate of your Opus files?
Post by: Klimis on 2018-01-25 01:12:07
96kbps is transparent to me. What I noticed is that up to 96kbps you get solid improvements for every 32kbps interval you give to the bitrate. After 96kbps, even if there is a difference for somebody, I bet the quality gain is less effective than the one given below 96kbps in 32kbps intervals. Not that there might be no quality gain, but most possibly not quite as big as the one you get for 32kbps intervals below 96kbps.
Title: Re: What is the bitrate of your Opus files?
Post by: j7n on 2018-01-25 07:35:00
I only have a small number of files in Opus, and I use 192 kbit/s, the old default for stereo sound. I see no attraction in seeking out the threshold of quality, and instead listen to the music without worry. The files are already quite tiny compared to flac and by any modern standards.
Title: Re: What is the bitrate of your Opus files?
Post by: KozmoNaut on 2018-01-25 09:07:18
I use 96kbps because it's the default setting, and because I haven't been able to pick out any artifacts when compared to the FLAC originals, even ABXing busy thrash metal with good headphones in a quiet room. So it is definitely going to be transparent on my car stereo with all the road noise and such.

adamOLC: How would you describe the artifacts you are hearing in black metal? I assume you're using at least Opus 1.2.
Title: Re: What is the bitrate of your Opus files?
Post by: includemeout on 2018-01-25 09:22:06
So it is definitely going to be transparent on my car stereo with all the road noise and such.
What have you been using for in-car listening? Bluetooth connnection?
Title: Re: What is the bitrate of your Opus files?
Post by: KozmoNaut on 2018-01-25 09:53:51
So it is definitely going to be transparent on my car stereo with all the road noise and such.
What have you been using for in-car listening? Bluetooth connnection?

Line-in from my phone.
Title: Re: What is the bitrate of your Opus files?
Post by: adamOLC on 2018-01-25 12:54:31
I use 96kbps because it's the default setting, and because I haven't been able to pick out any artifacts when compared to the FLAC originals, even ABXing busy thrash metal with good headphones in a quiet room. So it is definitely going to be transparent on my car stereo with all the road noise and such.

adamOLC: How would you describe the artifacts you are hearing in black metal? I assume you're using at least Opus 1.2.
What I hear (and this is the best way I can describe it) is distortion that is not present in the flac version.  It occurs the most with symphonic black metal and in particular with the band Evilfeast.  At first I did not notice it with IEMs, but heard it while in my car.  Thrash, death, etc. has yet to give me any artifacts that I can hear, only this particular genre of black metal.  I bumped these up to 160 bits and no longer hear the distortion.  I'm not sure if it's the combination of the fast guitars and drums along with the synthesizer  or what, but it was very noticeable in my car at higher volume versus my IEMs.

ETA: Yes, using Opus 1.2.
Title: Re: What is the bitrate of your Opus files?
Post by: includemeout on 2018-01-25 14:15:42
So it is definitely going to be transparent on my car stereo with all the road noise and such.
What have you been using for in-car listening? Bluetooth connnection?

Line-in from my phone.
Oh. It's definitely more reliable than BT (connection-wise). 
Title: Re: What is the bitrate of your Opus files?
Post by: KozmoNaut on 2018-01-25 15:15:33
What I hear (and this is the best way I can describe it) is distortion that is not present in the flac version.  It occurs the most with symphonic black metal and in particular with the band Evilfeast.  At first I did not notice it with IEMs, but heard it while in my car.  Thrash, death, etc. has yet to give me any artifacts that I can hear, only this particular genre of black metal.  I bumped these up to 160 bits and no longer hear the distortion.  I'm not sure if it's the combination of the fast guitars and drums along with the synthesizer  or what, but it was very noticeable in my car at higher volume versus my IEMs.

ETA: Yes, using Opus 1.2.

That's really interesting that you seem to be able to hear it better in the car, was it because you played at a higher volume than with the IEMs?

I did go back and give it a couple of tries at a higher volume level, with Vektor's "Pillars of Sand", specifically the busy bit starting around 0:48s, with the crashy cymbals.

I was able to get 7/8 and 6/8 correct multiple times, but never 8/8. It's very hard to nail down the exact difference, but it's something like a very wide noise/distortion, like it's "outside the headphones", it's hard to describe. It is also VERY subtle, to the point that I'm not sure whether I'm imagining it or simply guessing it. I would never be able to pick it out while listening to the actual music, only when repeating the same <1sec segment over and over and over again.

I had the same experience with LAME MP3 at -V5 (or -V4? I can't remember). I could get most of the trials right, but it was super hard to pinpoint the specific difference, and I would never notice it outside of an ABX test.

I'll have to give my car stereo a go at a high volume.
Title: Re: What is the bitrate of your Opus files?
Post by: KozmoNaut on 2018-01-25 18:41:04
Well, I couldn't hear any difference in my car, so I tried with my headphones again, with some Anaal Nathrakh (to use some of the busiest/dirtiest/noisiest music I have).

I used the PPHS Ultra resampler before (to resample to 48kHz for equal footing in regards to the DAC), but I read up on it, and apparently the SSRC resampler is better? Either way, with the SSRC resampler I absolutely cannot ABX any difference at 96kbps vs lossless now, I completely bombed every test, completely random. Both on the Anaal Nathrakh tracks and the Vektor track.

If there is a difference, it's too slight for my ears. Opus at 96kbps is astoundingly good.
Title: Re: What is the bitrate of your Opus files?
Post by: punkrockdude on 2018-01-25 18:43:35
Even though Opus is impressive I want to extra headroom and feel quite sure that I won't notice any artifact at all and therefore I have stopped at 128kbps using opus 1.2.1. I think the poll could have had two seperate questions; "what bitrate do you use for music" and "what bitrate do you use for voice recordings" since opus i so impressive for voice recordings.
Title: Re: What is the bitrate of your Opus files?
Post by: adamOLC on 2018-01-25 20:21:14
What I hear (and this is the best way I can describe it) is distortion that is not present in the flac version.  It occurs the most with symphonic black metal and in particular with the band Evilfeast.  At first I did not notice it with IEMs, but heard it while in my car.  Thrash, death, etc. has yet to give me any artifacts that I can hear, only this particular genre of black metal.  I bumped these up to 160 bits and no longer hear the distortion.  I'm not sure if it's the combination of the fast guitars and drums along with the synthesizer  or what, but it was very noticeable in my car at higher volume versus my IEMs.

ETA: Yes, using Opus 1.2.

That's really interesting that you seem to be able to hear it better in the car, was it because you played at a higher volume than with the IEMs?

I did go back and give it a couple of tries at a higher volume level, with Vektor's "Pillars of Sand", specifically the busy bit starting around 0:48s, with the crashy cymbals.

I was able to get 7/8 and 6/8 correct multiple times, but never 8/8. It's very hard to nail down the exact difference, but it's something like a very wide noise/distortion, like it's "outside the headphones", it's hard to describe. It is also VERY subtle, to the point that I'm not sure whether I'm imagining it or simply guessing it. I would never be able to pick it out while listening to the actual music, only when repeating the same <1sec segment over and over and over again.

I had the same experience with LAME MP3 at -V5 (or -V4? I can't remember). I could get most of the trials right, but it was super hard to pinpoint the specific difference, and I would never notice it outside of an ABX test.

I'll have to give my car stereo a go at a high volume.
I definitely listen louder in the car.  I haven't gone back and abx  it all.  I should also add, this was over Bluetooth, yet it was all aptx so I don't think that was the cause of it.  Evilfeast in particular has very bright sounding production.  The synth is almost constant throughout, but the artifacts weren't present on every track.  Once I bumped it up to 160, the artifacts went away.  I've tried with other tracks (Vektor included) that are busy or even similar, but it doesn't occur with them.  Eventually, I'll have some time to sit down and really test and listen, but the kiddos make it hard to get any quiet time...lol
Title: Re: What is the bitrate of your Opus files?
Post by: arkhh on 2018-01-26 10:12:58
I use 48 kpbs opus for my sansa clipzip, just because I didn't want to buy a new microSD card. Is it transparent? no. But I find the artifacts "non-distracting". For portable use when moving, in a noisy environment, not paying too much attention to the music... quality is not a concern. When I have time for critical listening is when I'm at home, there I just play the lossless original files.
Title: Re: What is the bitrate of your Opus files?
Post by: KozmoNaut on 2018-01-26 10:53:36
I think it's interesting to encode some music at 6kbps -- the very lowest bitrate Opus supports -- just to truly hear the codec in action.

Yes, it will have artifacts and be rather noisy, with severely reduced frequency range. But it is absolutely amazing how much of the music still comes through. You can pick out bass lines and most of the melody, and the vocals are intelligible.
Title: Re: What is the bitrate of your Opus files?
Post by: fabiorug on 2018-01-26 19:28:29
64 kbps. I use a new build of Opus (new -tf build)..
I hope Opus 1.3 will really bring improvements to 24 - 48 kbps.  For higher bitrates I haven't tested.
Title: Re: What is the bitrate of your Opus files?
Post by: IgorC on 2018-01-27 13:43:58
fabiorug
As You're new here let me tell  that using alpha versions of codec is a not precisely a good idea. You can try it (and you should in order to help to test it)  but there might be a serious bugs.

Until moment there are no evidences that 1.3 (or new -tf ) is any better than 1.2.1
Title: Re: What is the bitrate of your Opus files?
Post by: fabiorug on 2018-01-27 15:50:44
I know there isn't evidence about improvements at 64 kbps.  I tezted only with a sample ( I know it isn't good)..
Title: Re: What is the bitrate of your Opus files?
Post by: Duceboia on 2018-01-27 17:23:14
No ABX  made, I feel 96kbps good enough for mobile... I listen to my music without evident artifacts.
little to little I'm cancelling all Big mp3 from my phone's SD, replacing them with OPUS.... only when I have lossless for conversion.
Title: Re: What is the bitrate of your Opus files?
Post by: soundping on 2018-01-27 19:22:38
I play it safe at 160.
My phone has 256GB card so space isn't problem.
Title: Re: What is the bitrate of your Opus files?
Post by: KDDLB on 2018-01-28 01:28:54
I transcode the audio of DVR recordings from surround AC-3 to stereo 64kbps Opus.
Title: Re: What is the bitrate of your Opus files?
Post by: Franky666 on 2018-01-30 12:45:02
16kbps. :D

I'm using Opus for speech recording only. For that, this bit rate is enough. I don't need it for music or movies.

My CD collection is stored in FLAC :D . I re-ripped my 1000 CD's to FLAC last year to get rid of MP3 at all. For mobile, I convert from the FLAC archive down to Vorbis.
Title: Re: What is the bitrate of your Opus files?
Post by: ThaCrip on 2018-05-08 08:40:28
Looking through the comments in here etc etc, it seems the following four choices are best, especially if one has some concern for efficiency...

-48kbps = Usable, especially if storage space is of higher concern and you don't mind sacrificing some sound quality. hell, even 32kbps is respectable in the overall quality of the sound for such a low bit rate but I can't imagine most people going under 48kbps unless they heavily favor storage space over sound quality.

-64kbps = This is what I would suggest as a minimum for music in general as overall sound quality is 'good enough' and file size is minimal. I suspect this would be 'good enough' for many people.

-80kbps = This is probably a good choice for those who don't mind the 64kbps setting but want to play it a bit safer in sound quality and are still looking for solid efficiency.

-96kbps = It seems many agree this setting is quite good in sound quality and is still efficient. any higher and Opus starts to lose it's appeal as I figure 128kbps would be the limit I would consider for Opus since beyond that seems overkill and efficiency would be mostly shot beyond 128kbps.

all-in-all... I voted for the 64kbps setting for now since I tend to view Opus as trying to get maximum efficiency without sound quality taking any obvious drop offs on a typical song when just listening to your music and enjoying it without having to focus too much to spot artifacts. I suspect 64kbps would please many people. also, I basically see Opus as a slightly more efficient version of AAC and to get those benefits it seem to be 96kbps-ish and lower as once you get into the 128kbps+ ranges your probably better off using Apple AAC for compatibility sake.

NOTE: I don't really use Opus much, but when I do, it pretty much boils down to the above comments. if Opus was more standardized, and especially if my old Sandisk Sansa e250 v1 player (2GB internal memory, with a 16GB MicroSD card = 18GB total storage space) worked well with it(it seems it's a bit too CPU intensive on Rockbox), there is a pretty good chance I would be using it over Apple AAC @ 128kbps (lowest I would use on Apple AAC would be 96kbps).

p.s. I use Opus for speech @ 14-16kbps as I feel the 14kbps setting is about the lowest I would suggest before the quality starts to take a decent hit.
Title: Re: What is the bitrate of your Opus files?
Post by: Deathcrow on 2018-05-18 12:49:45
I basically see Opus as a slightly more efficient version of AAC and to get those benefits it seem to be 96kbps-ish and lower as once you get into the 128kbps+ ranges your probably better off using Apple AAC for compatibility sake.

Compatibility isn't the only concern that matters to some people. Even if Opus and Apple AAC are roughly equivalent at bitrates of 128+kbps I still vastly prefer to use an open, non-proprietary, codec. One of the most amazing things about Opus is that it is free AND is at least on par with - if not better than - most other audio codecs
Title: Re: What is the bitrate of your Opus files?
Post by: Anakunda on 2018-05-19 07:46:18
Interesting so many users prefer 128k over 96. Is that because of hearing true artifacts or to ensure sufficient buffer above the point of transparency?
Title: Re: What is the bitrate of your Opus files?
Post by: ThaCrip on 2018-05-19 08:53:32
@Deathcrow

Quote
Compatibility isn't the only concern that matters to some people. Even if Opus and Apple AAC are roughly equivalent at bitrates of 128+kbps I still vastly prefer to use an open, non-proprietary, codec. One of the most amazing things about Opus is that it is free AND is at least on par with - if not better than - most other audio codecs

Yeah, Opus is solid as it's basically #1 as the only obvious thing going against it is hardware support of which, as you already know, MP3/AAC are easily the most widely supported. but if your device supports Opus, I prefer it over those two and at this point in time I figure it's not worth using any other lossy formats besides MP3/AAC/Opus.

in fact, I just started (roughly in the last 2-3 days or so) using Opus @ 64kbps(for less important music) and 80kbps(for more important music) as I got a hold of a older phone (Huawei y336-A1 (which I rooted with Kingroot)) which I just use mainly for a portable music player and installed the mobile version of Foobar2000 on it and it works great with Opus. running a benchmark (in Foobar2000 mobile on the phone) on the Opus files I made(from FLAC of course), with one CPU core, it decodes the Opus files a little over 40x real-time. it sips battery to as I used it for roughly 40min-1hr earlier and the phones battery only dropped about 3% or so.

I got a 8GB MicroSD card in the phone so in order to fit my entire music collection in it, using Opus was even more beneficial as before my general music collection took up roughly 10-11GB with 128kbps AAC(for more important music)/96kbps AAC(for less important music). but now, while I don't have everything in the phone yet, it's a little less than 4GB with the 64kbps/80kbps Opus combo. I would imagine if I got everything on it, probably won't go over about 5GB.

p.s. funny thing is... I had that old phone no one was using laying around for a little while now but I never even thought to use it for Opus playback on the go as it just popped into my head to try it and it worked great.

side note: I was recently playing with AAC and I was surprised that AAC-LC @ 64kbps that TVBR mode sounds noticeably better than CVBR mode and not only that the CVBR file was actually a bit higher bit rate than the TVBR file. like when ABXing, without even finishing the test, it was pretty easy for me to tell what was the FLAC file and what was the CVBR file given the CVBR file had a muffled sound to the overall sound where as with the TVBR file that was not there which makes it more difficult to tell the TVBR from the FLAC as I got to pay more attention to random artifacts as it's not as obvious since the TVBR sound has a similar clarity to the FLAC in a basic sense which is missing in the CVBR file which make that one easy to spot. but I noticed in Foobar2000 when encoding 64kbps Apple AAC files is that when using TVBR it does not attempt to use any AAC-HE mode (or the like) where as when using CVBR it wants to use that AAC-HE mode as I had to uncheck that option so it used AAC-LC.

@Anakunda

Quote
Interesting so many users prefer 128k over 96. Is that because of hearing true artifacts or to ensure sufficient buffer above the point of transparency?

Yeah, I would not be surprised if for some it's sort of a safety buffer especially with Opus given it seems to do quite well at 96kbps. hell, I would imagine I might even be able to claim that Opus @ 80kbps might be roughly equivalent to Apple AAC @ 96kpbs(?).

but in general I feel with modern encoders anything above 128kbps basically loses efficiency for sure as it seems like once you go beyond that, the gains are pretty much minimal if not very minimal. so basically... I think in most situations 128kbps is more than enough bit rate for quality sound.

but anyways, I can't imagine many disliking 96kbps Opus given the sound tests from 2014 show it scores pretty darn good... https://hydrogenaud.io/index.php/topic,106911.0.html ; so given that test, which is 96kbps setting for Opus, it seems like beyond 128kbps would be overkill and mostly a waste of disc space for most people. that's kind of why I see Opus to be mainly worth using in the 96kbps and lower ranges since that's when Opus is at it's best as at the higher bit rates (say 128kbps or higher, especially higher) it seems like you can just pretty much pick whatever format you want and they are all roughly the same.

as for myself... I seem to be similar to some others around here where 80kbps (for Opus) is pretty much high enough for me, especially when I am trying to squeeze the file size down as much as I can etc. although 64kbps is still quite usable for me even though I went with 80kbps as a little bit of a safety buffer for me on my more important music.

but at the end of the day... I could see how many would see the 128kbps rate as the 'just use it and forget about it' setting as if you rip your music collection at that rate you won't need to re-rip it again for lack of quality and yet it's still efficient. that's sort of why I got the 'I suggest 128kbps for most people' in my signature for Apple AAC and one could probably apply that to Opus to (even though Opus @ 96kbps might be close enough to the general 128kbps option) as 128kbps seems to be that setting to where it's that great balance between efficiency, but not taking any shortcuts on sound quality either.

p.s. I voted for the 64kbps setting in the poll but I probably should have went with 80kbps especially if Opus @ 80kbps is roughly equivalent to Apple AAC @ 96kbps as it seems like with Apple AAC that 96kbps is sort of a minimum around here for quality sound for Apple AAC. still, Opus @ 64kbps is still quite respectable if one is a bit more concerned with file size than sound quality but not sacrificing overall sound quality too much.
Title: Re: What is the bitrate of your Opus files?
Post by: ThaCrip on 2018-05-24 01:42:32
UPDATE: while I already mentioned I voted for 64kbps, which ain't bad for the bit rate, it seems like 96kbps is what I would vote for now since it's a safe setting for most people and I figure it's not worth gambling (on sound quality loss) on the lower bit rates for important music to squeeze a little extra space savings and Opus @ 96kbps scores very well in listening tests so there is no real need to use higher than 96kbps with Opus in general.

I recently re-converted my FLAC collection to 96kbps (was using 80kbps) just to play it safe (sound quality wise) for my more important music but I still left the less important music at 64kbps (that combo gives me ample room for adding more music to the 8GB MicroSD card in the future).

NOTE: one song I set to 96kbps, had a average bit rate of 138kbps (i.e. 'They Broke His Pelvis' track from the Drive (2011) soundtrack). but my overall music collection (1,205 songs) averages 99kbps so far which is about expected since it's around 96kbps but it's a bit surprising to see 138kbps from the 96kbps setting. only about 4 songs cracked 130kbps+.

p.s. if I wanted to really nitpick and squeeze out every last drop out of Opus I 'may' be able to try going between the 80 and 96kbps setting to 88kbps, but it's not really worth messing with for the little storage space savings and we know 96kbps is a strong sound quality setting given the tests around here. so for anything important I think 96kbps is going to be my default Opus setting now as it should be a safe setting that I can say, 'use it and forget about it'.
Title: Re: What is the bitrate of your Opus files?
Post by: ThaCrip on 2018-05-26 10:21:56
96kbps is transparent to me. What I noticed is that up to 96kbps you get solid improvements for every 32kbps interval you give to the bitrate. After 96kbps, even if there is a difference for somebody, I bet the quality gain is less effective than the one given below 96kbps in 32kbps intervals. Not that there might be no quality gain, but most possibly not quite as big as the one you get for 32kbps intervals below 96kbps.

Yeah, I think what you say there would be difficult to disagree with given listening tests around here (which should be a pretty good estimate of Opus quality) because going by 32kbps bit rate increases, 32/64/96/128/160 etc, it seems like once you hit 96kbps things tend to largely peak in sound quality to where going higher, the sound quality gains tend to be minimal, and once you hit 160kbps seem to be pretty much the limit and going any higher seems to be largely overkill/waste of storage space (based on some comments I have read around here). so I kind of assume the difference between 96kbps vs 160kbps is minimal(if not very minimal) overall and probably requires optimal listening conditions etc to notice it. like it becomes more of a the thought of them being able to ABX it (at 96kbps vs say 128kbps or 160kbps) more than the difference actually bothering them (because the difference is faint) when just sitting back and enjoying the music.

so based on what your saying it might be roughly something like this, sticking to the 32kbps each increase standard...

32kbps to 64kbps = biggest gap in sound quality.
64kbps to 96kbps = a decent gap in sound quality. (largely cleans up the already pretty good sound to where artifacts should be pretty minimal at this point(96kbps))
96kbps to 128kbps = small gap in sound quality.
128kbps to 160kbps =smaller gap in sound quality.
160kbps to 192kbps or higher = smallest gap in sound quality. probably next to nothing in sound quality(?). basically efficiency is pretty much shot any higher than 160kbps from the looks of things.

so basically 96kbps offers the most sound quality for the bit rate basically (especially sticking to the 32kbps increase standard) which pretty much makes it that 'sweet spot' for Opus. I just said 'pretty much' just to leave a little lee-way in there as if someone disagreed with me, it can't be more than one setting either way of 96kbps sticking to the 32kbps (up or down in bit rate) standard. so in other words, the 'sweet spot' for just about everyone, who has a concern for efficiency, would be basically one of the following settings... 64kbps/96kbps/128kbps. so basically 128kbps is for those who are a bit more concerned with sound quality than storage space/efficiency and 64kbps is for those a bit more concerned with storage space than sound quality where as 96kbps is basically that great balance between the two. so while 160kbps is still a respectable choice, I don't really think someone could argue in favor of 160kbps in terms of efficiency as while it's probably a solid option for those who want maximum sound quality without getting too crazy with the bit rate, so it's not a total loss of efficiency, it does tend to take a solid hit in efficiency for minimal sound quality gains which makes it a little too high if you ask me since I sort of see 128kbps as a bit of a safety buffer for the already strong 96kbps setting (so it's not too surprising to see 128kbps the current leader in the poll with 96kbps being the 2nd choice) but even that already comes with a 25% increase in storage space etc.
Title: Re: What is the bitrate of your Opus files?
Post by: Klimis on 2018-05-26 13:28:08
Until recently I was using 96kbps for Opus but I noticed that over 10000Hz or 12000Hz alot of the stereo field gets centered (Something similar happens with Vorbis at those bitrates) so I jumped to 128kbps where I notice nothing. It just cant be my imagination.
Title: Re: What is the bitrate of your Opus files?
Post by: IgorC on 2018-05-26 20:00:32
More likely it's Intensity Stereo (IS).
IS is beneficial for bitrates  less than 130 kbps.
IS is applied on frequency range of 12-20 kHz (at 96 kbps), 15.6-20kHz(128 kbps) and it's completely deactivated at 130+ kbps.
 
https://tools.ietf.org/html/rfc6716
Intesity stereo (table 66)
Frequency bands (table 55)
 https://people.xiph.org/~xiphmont/demo/celt/bands.png

Title: Re: What is the bitrate of your Opus files?
Post by: ThaCrip on 2018-05-27 02:53:46
@Klimis

Quote
stereo field gets centered

Maybe this is a bit of a noob question, but when you say that, do you mean that how some stereo music sound switches from left to right speakers normally that it's less like that and plays more in the center (so is played through both speakers when it's normally more one or the other)?

if that's the case, that would not bother me as I generally prefer the general music to be in both speakers anyways.
Title: Re: What is the bitrate of your Opus files?
Post by: kode54 on 2018-05-27 03:03:33
Maybe it collapses a phase offset between the two channels. I always hated weird phase offsets anyway, but that sounds like a bug.
Title: Re: What is the bitrate of your Opus files?
Post by: Klimis on 2018-05-27 13:04:56
More likely it's Intensity Stereo (IS).
IS is beneficial for bitrates  less than 130 kbps.
IS is applied on frequency range of 12-20 kHz (at 96 kbps), 15.6-20kHz(128 kbps) and it's completely deactivated at 130+ kbps.
 
https://tools.ietf.org/html/rfc6716
Intesity stereo (table 66)
Frequency bands (table 55)
 https://people.xiph.org/~xiphmont/demo/celt/bands.png


I believe that's it.
It just feels like there is way less Stereo information above 12kHz.
It took me a while to notice it at 96kbps but now I can hear it on tracks with weird panning effects. At 128kbps though I hear nothing, I guess it's way above the threshold of what I can perceive as stereo or mono information. BTW as I said I can hear it also on Vorbis files, it's even more noticeable on those. I guess other that Xilph's codecs I don't hear anything at those bitrates (like AAC).
Title: Re: What is the bitrate of your Opus files?
Post by: IgorC on 2018-05-27 22:26:58
Several years ago I've tested intensity stereo (IS) at different start bands (18,19 and 20) on 1.1 alpha version. Results were that default 19 start band at 96 kbps was the most optimal.

IS codes stereo audibly lossy at high frequencies  but it saves bits which can be used at lower frequencies and those are  considerably more audible.  In a few words, default IS behavior brings more benefit than harm in Opus encoder.

(All three Vorbis, Opus and AAC code HF stereo by implementing intensity stereo or similar techniques. Vorbis is the worse that's for sure.  Not sure about Opus vs AAC however even the highest quality AAC encoders present audibly stereo artifacts as well (at 96 kbps)).
What important is a big picture. Opus still performs better than any AAC encoder at 96 kbps. Types and origins of artifacts may be different.

P.S. I'm not sure but I think there were some enhancements to IS (variable threshold ?).  Variation of artifact can be more audible than if artifact was constant.
Title: Re: What is the bitrate of your Opus files?
Post by: ThaCrip on 2018-08-04 09:57:17
After some more testing recently I seem to have settled on Opus @ 64kbps as that seems to be the point where the sound quality reaches a solid/stable enough point on a wider range of music I have on my PC's Klipsch Pro-Media speakers (for home usage) along with my Sony MDR-NC7 headphones on the Huawei y336-A1 device (for portable usage) and basically determined between both of those that 64kbps seems to be that bit rate where the sound quality is more stable across the music I tested as going down to 48kbps seems to be a little too much of a drop off in sound quality with certain songs etc on the PC speakers and increasing bit rates beyond 64kbps does not seem to be enough of a improvement(especially on my headphones/Huawei device) to justify the extra bit rate.

like some music seems decent enough @ 48kbps but then others seems to be a bit more so-so (I am using Opus v1.3RC (the one NetRanger posted July 28th 2018)), but that problem seems to disappear at 64kbps. plus, another bonus with 64kbps is that I can fit all of my music on a 8GB MicroSD card with a fair amount of space left over for future expansion.

so what I voted for, which is 64kbps, is what I am likely going to stick with for general Opus encoding bit rate for lossy music especially on-the-go with my headphone/smart phone setup. sure, if I was going to make more of a proper archive for lossy music with Opus I would likely use 96kbps (maybe 128kbps tops) as that seems more of a safe minimum to cover more of a wider range of hardware. but 64kbps seems to be a high enough bit rate that I doubt ill hear any more obvious sound quality drop offs over a wider range of music (and probably still won't sound too bad for many straight up). but who knows, if I had higher quality headphones maybe I would feel a bit differently but I think my headphones are more in the average range where as my PC speakers are in the above average range.

also, I can't say for sure at the moment but my general impression given my testing lately is that when playing Opus @ 48kbps it seems a bit easier to spot artifacts with my PC's speakers than it is with the same files on my headphones on the Huawei device for music on-the-go.

p.s. so my previous post with me wanting to change my vote from 64kbps to 96kbps, I retract that statement, especially for music on-the-go with average range of headphones. so that 'playing it safer' with 96kbps etc that I was mentioned... while it's probably still true to some degree, given my more recent testing, the sound quality improvement beyond 64kbps are basically minimal with my hardware (i.e. Klipsch Pro-Media speakers (above average speakers) and Sony MDR-NC7 headphones (average range of headphones) on the Huawei device) which makes 64kbps a great balance of sound quality to file size for those of us with average range of headphones and a pretty good set of speakers.
Title: Re: What is the bitrate of your Opus files?
Post by: aguacaliente on 2018-08-09 21:23:41
I have 1309 Opus files, all mid-60's R&B, on a flash drive to play at work using fb2k.   I set at 80kbps to encode.  The actual bitrates for the 777 mono files ranged from 52-74 and averaged 66.  Bitrates for the 532 stereo files ranged from 71-110 and averaged 79.
Title: Re: What is the bitrate of your Opus files?
Post by: Porcus on 2018-08-09 22:46:27
For in-car use (cell phone -> bluetooth), I have a strange mix from lossless all the way down to Opus 48. The reason is in part laziness (just copying CD rips from my hard drive rather than encoding) and in part hurry - encoding to opus 48 to save transfer time. Fidelity in car isn't really crucial to me, and because I am really impressed at how much music you can get into low bitrates, I will probably go 40 next time ... if I remember to fix the preset. (Encoding metal at "32" gives me 40, it seems. Edit: the "48" isn't 48, it is somewhere in the fifties.)

I think it's interesting to encode some music at 6kbps -- the very lowest bitrate Opus supports -- just to truly hear the codec in action.

Yes, it will have artifacts and be rather noisy, with severely reduced frequency range. But it is absolutely amazing how much of the music still comes through. You can pick out bass lines and most of the melody, and the vocals are intelligible.

Yeah. But 6 kb/s is just for the hell of it. Kinda like 32 kb/s MP3 was back in the day.
That said, you surely got intelligible (but noisy) voices with the GSM "half-rate" voice codec at 5.6 kb/s, a codec about the age of MP3. Bearing that in mind, it is not that surprising to hear a bit more music from a twenty-five years more modern codec - that is not constrained to battery-frugal encoding on a 90s phone CPU.
Title: Re: What is the bitrate of your Opus files?
Post by: IgorC on 2018-08-10 21:53:26
(Encoding metal at "32" gives me 40, it seems. Edit: the "48" isn't 48, it is somewhere in the fifties.)
Hm, that's strange.  What kind of metal do You listen?
Opus encodes metal genre at lower bitrate than nominal one.
I got always few/several kbps less on my collection of hard rock, speed/thrash/heavy metal.

- b 32 gives me 30-31 kbps
- b 48  gives 46 kbps
so on ....


Title: Re: What is the bitrate of your Opus files?
Post by: Sajadi on 2018-08-11 13:21:44
256 kbps - because with that rate i am 100% on the secure side of sound quality - and works great for converting Amiga/C64 music too.
Title: Re: What is the bitrate of your Opus files?
Post by: Porcus on 2018-08-11 14:57:49
Hm, that's strange.  What kind of metal do You listen?
Opus encodes metal genre at lower bitrate than nominal one.

Huh?  I don't anymore remember what I tested on then, but I absolutely cannot reproduce. Thanks for the heads-up.

The worst I encountered by doing some random testing right now, was Until Death Overtakes Me: nominally 29 (which was the "low" setting I had tested and stored) - actually 33.
"Corpus": all the tracks that Stijn van Cauter released under the UDOM moniker in FLAC format at Archive.org. Check out his works at
https://archive.org/details/nulll-records and http://nulll.net/udom/
Title: Re: What is the bitrate of your Opus files?
Post by: ThaCrip on 2018-08-12 03:42:05
256 kbps - because with that rate i am 100% on the secure side of sound quality - and works great for converting Amiga/C64 music too.

Anything beyond 192kbps is overkill with Opus given the info on the Wiki page...

-96kbps  = 'approaching transparency'
-128kbps = 'very close to transparency'
-160-192kbps = 'Transparent with very low chance of artifacts (a few killer samples still detectable)'

bottom line... the vast majority of people would likely want to use one of those three settings (i.e. 96kbps/128kbps/160kbps) or so if they are more concerned with sound quality but still want some level of efficiency. or I could say this.... I am confident the vast majority of people would not really need more than 128kbps for listening to music on-the-go and on most equipment, like headphones/speakers.

but with all of that said... thanks for your input ;)

p.s. personally... I think in most situations (most headphones/speakers etc) 96kbps is the sweet spot of Opus. or I might even say this... 64kbps = for someone more concerned with storage space but still wants a passable level of sound quality on your typical set of speakers/headphones. 96kbps = for general usage. 128kbps = for the more sound quality conscious types. it's unlikely 128kbps is not high enough for the vast majority of people given the Opus wiki info as 128kbps says 'very close to transparency' which means one has to nit pick beyond this level of sound quality which is why I feel using bit rates beyond 128kbps with Opus are mostly a waste of storage space, especially if you got a lot of music.
Title: Re: What is the bitrate of your Opus files?
Post by: Sajadi on 2018-08-12 11:32:56
Anything beyond 192kbps is overkill with Opus given the info on the Wiki page...

-96kbps  = 'approaching transparency'
-128kbps = 'very close to transparency'
-160-192kbps = 'Transparent with very low chance of artifacts (a few killer samples still detectable)'

In most cases yes, but 256 kbps is for me the best and reasonable value to convert for example C64 sid files or chiptunes in general - At that level i am unable to hear any differences anymore in most cases.

But yeah, for the majority of other music, 160-192 kbps is more than enough :)
Title: Re: What is the bitrate of your Opus files?
Post by: yourlord on 2018-08-15 20:27:41
I do 112kbps these days. I used to do 96kbps and would still be perfectly happy there, but I got to where every once in awhile I could notice an odd artifact here and there. Storage space isn't much of a concern these days so I just bumped to 112k and haven't noticed anything since. The majority of my music is metal, mostly heavy/thrash/death/power/every other subsubsubgenre, and some classical and opera.
Title: Re: What is the bitrate of your Opus files?
Post by: ThaCrip on 2018-08-16 01:00:24
The majority of my music is metal, mostly heavy/thrash/death/power/every other subsubsubgenre, and some classical and opera.

I am surprised you can listen to 'Death Metal' as that music is horrible, but yet, you still like Classical. maybe I am mistaken, but I would not expect to find many people who like Classical liking Death Metal or vice versa.

I see Classical and Death Metal as polar opposites as I always thought that Classical music is the closest music one can get to Heaven and Death Metal is the closest music one can get to hell as Death Metal just screams negativity.

basically... Death Metal is the only music I cannot stand. because while there is other music I don't care for that's the only one that stands out in a negative way.

with that said... thanks for your input.
Title: Re: What is the bitrate of your Opus files?
Post by: Musique-Rabbit on 2018-08-16 02:13:18
For music (especially on-the-go)...
-I suggest Opus @ 96kbps (or... 64kbps minimum, 128kbps maximum). *preferred choice*
-I suggest AAC(Apple) @ 96kbps (q45 TVBR) or 128kbps (q64 TVBR). *secondary choice*
-I use Foobar2000 (/w Encoders Pack etc) to convert FLAC to Opus/AAC(Apple).

Mine is exactly the same as that of ThaCrip.
Title: Re: What is the bitrate of your Opus files?
Post by: Deathcrow on 2018-08-16 10:13:07
I am surprised you can listen to 'Death Metal' as that music is horrible, but yet, you still like Classical. maybe I am mistaken, but I would not expect to find many people who like Classical liking Death Metal or vice versa.

I see Classical and Death Metal as polar opposites as I always thought that Classical music is the closest music one can get to Heaven and Death Metal is the closest music one can get to hell as Death Metal just screams negativity.

There's plenty of people in the metal scene who listen to and enjoy classical music, who also like Death Metal - and so do I. I'd be careful when your personal taste and confusions make your judgment of other people flawed. I assume Classical Music might very well be the second most popular genre among Death Metal fans. This shouldn't come as a surprise, considering the large amounts of orchestrated albums and live shows performed by Metal artists. Just a few examples to illustrate my point:

Satyricon (https://www.youtube.com/watch?v=pwU22xcDiJ4)

Dimmu Borgir (https://www.youtube.com/watch?v=Cg6n3ZhKwt4)

Apocalyptica (https://youtu.be/_up0o5a6tfM?t=2516)

Rage (https://youtu.be/cTqPCVl18Z4?t=924)

In fact there exists an entire Death Metal Symphony by Waltari:

Death Metal Symphony (https://www.youtube.com/watch?v=5CWC8ic3Puc)

But (Death) Metal really doesn't need its Classical influences to be legitimized, incredible compositions (https://www.youtube.com/watch?v=lGEoJLIIuow) can stand (https://www.youtube.com/watch?v=LnGbYQpK0ts) proudly on their own (https://www.youtube.com/watch?v=zRI5ajsKRFM) two feet (https://www.youtube.com/watch?v=_HAt8ETevVE).

Sorry for the tangent, but this needed to be addressed.
Title: Re: What is the bitrate of your Opus files?
Post by: milesrotaru on 2018-08-16 13:47:33
256 kbps - because with that rate i am 100% on the secure side of sound quality - and works great for converting Amiga/C64 music too.

If you're fine with that bitrate you may as well just use a time domain subband codec like MusePack or hell, even MP2, and enjoy the perfect temporal resolution. Throwing more bits at a transform codec doesn't do much to fix their fundamental shortcomings beyond 192 kbps.
Title: Re: What is the bitrate of your Opus files?
Post by: Duceboia on 2018-08-16 19:19:07
Count me in!  I love my Black/Death Metal but I love Mahler too.
Title: Re: What is the bitrate of your Opus files?
Post by: IgorC on 2018-08-16 21:18:44
If you're fine with that bitrate you may as well just use a time domain subband codec like MusePack or hell, even MP2, and enjoy the perfect temporal resolution. Throwing more bits at a transform codec doesn't do much to fix their fundamental shortcomings beyond 192 kbps.
Is there any  recent blind test which  indicates superiority of MPC over other codecs?

I've found only these old tests:
https://hydrogenaud.io/index.php/topic,36465.msg321547.html#msg321547
(http://audiotests.free.fr/tests/2005.08/HQ180/HQ180results.png)

And  this old one
http://listening-tests.freetzi.com/html/Multiformat_128kbps_public_listening_test_results.htm
(http://listening-tests.freetzi.com/html/Multiformat_128kbps_public_listening_test_results_files/plot18z0.png)


Title: Re: What is the bitrate of your Opus files?
Post by: foxyshadis on 2018-08-17 10:55:49
256 kbps - because with that rate i am 100% on the secure side of sound quality - and works great for converting Amiga/C64 music too.

If you're fine with that bitrate you may as well just use a time domain subband codec like MusePack or hell, even MP2, and enjoy the perfect temporal resolution. Throwing more bits at a transform codec doesn't do much to fix their fundamental shortcomings beyond 192 kbps.
I don't understand at all what you call out as time-domain, when your examples of MP2 and MPC are both frequency-domain.
Title: Re: What is the bitrate of your Opus files?
Post by: IgorC on 2018-08-17 15:48:11
Here is  a personal test @200 kbps Opus/Musepack/Apple AAC/Vorbis/MP3 of HA member, StreveForteRio
https://translate.google.com/translate?hl=en&sl=ru&tl=en&u=https%3A%2F%2Faudiophilesoft.ru%2Fnews%2F200_kbps_abc%2F2014-06-27-105

Avearge results:

Opus - 5 (all samples are transparent)
Musepack - 5 (all samples are transparent)
Apple/QAAC - 4.6
Vorbis - 4.4
LAME - 3.6
Title: Re: What is the bitrate of your Opus files?
Post by: milesrotaru on 2018-08-18 06:46:01
I don't understand at all what you call out as time-domain, when your examples of MP2 and MPC are both frequency-domain.

Well they both use a simple filter to split the spectrum into 32 bands but each band is PCM coded. A full blown FFT can be used for psychoacoustic decisions but that data is discarded.
Title: Re: What is the bitrate of your Opus files?
Post by: Sajadi on 2018-08-18 23:29:36
If you're fine with that bitrate you may as well just use a time domain subband codec like MusePack or hell, even MP2, and enjoy the perfect temporal resolution. Throwing more bits at a transform codec doesn't do much to fix their fundamental shortcomings beyond 192 kbps.

Still does not change the fact that i love to convert with Opus - it has become my favorite Open Source codec. Flawless in every kind of ways :)
Title: Re: What is the bitrate of your Opus files?
Post by: firechip on 2018-12-24 06:56:53
320 kbps vbr. This matches the same file size as mp3 320 but with much higher quality. Even then if you cherry pick your songs you can still guess the flac. I like keeping 320 as the standard number.
Title: Re: What is the bitrate of your Opus files?
Post by: m14u on 2018-12-24 08:21:34
320 kbps vbr. This matches the same file size as mp3 320 but with much higher quality. [...]
sorry, can't refrain:
x kbps vbr. This matches the same file size as mp3 x but with much higher quality
    there x>0
;)
Title: Re: What is the bitrate of your Opus files?
Post by: includemeout on 2018-12-25 00:16:04
320 kbps vbr. This matches the same file size as mp3 320 but with much higher quality. [...] I like keeping 320 as the standard number.
 
Which, in this particular case-  i.e, not being properly backed up by a blind test - quite possibly translates into an overkill as well as a TOS #8 infrigement.
Title: Re: What is the bitrate of your Opus files?
Post by: magicgoose on 2018-12-25 11:47:39
`--bitrate 128 --no-phase-inv`
128 because 96 is where it starts to be transparent for me and I'd like to have a little bit of safety margin
--no-phase-inv because from what I've read I definitely don't want out of phase sounds; if it decides it not worthy to encode sound location the it'd better be just normal mono instead of out of phase mono. Opus encoder will probably not use this trick at this quality level anyway, but this option shouldn't hurt either way...
Title: Re: What is the bitrate of your Opus files?
Post by: seventhstar on 2019-01-23 19:36:25
`--bitrate 128 --no-phase-inv`
128 because 96 is where it starts to be transparent for me and I'd like to have a little bit of safety margin
--no-phase-inv because from what I've read I definitely don't want out of phase sounds; if it decides it not worthy to encode sound location the it'd better be just normal mono instead of out of phase mono. Opus encoder will probably not use this trick at this quality level anyway, but this option shouldn't hurt either way...

Then it is worth using --no-phase-inv? Disables the use of phase inversion for intensity stereo. Because that exchanges some stereo quality for a higher quality mono down mix, which they say is useful when you encode stereo audio that will probably become mono after decoding.
It reminds me of the discussion of stereo vs. joint stereo vs. intensity stereo.
Title: Re: What is the bitrate of your Opus files?
Post by: David Swanson on 2019-01-25 21:21:07
One metric I use for lossy codecs is the 1MB/minute rule.  Regardless if its Opus, AAC-itunes, Vorbis or LAME, to my ears, whatever the latter codecs, it is fine.  Anything greater 1MB/Min vbr encoding in my opinion, is diminishing return to quality/storage consumption.
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