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Topic: Point of transparency of Opus 1.2 (Read 10591 times) previous topic - next topic
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Re: Point of transparency of Opus 1.2

Reply #25
Did some Foobar2k ABX testing using the "Bachpsichord" and "Applaud" samples:

Bachpsichord sample*
  Opus@64kbps          : Guessing Probability 0.0%
Applaud sample*
  Opus@64kbps, @96kbps : Guessing Probability 0.0%
Well, the more interesting question (at least to me) is: what an Opus bitrate setting does it take to have a) applaud, b) barpsichord being transparent to you.
lame3995o -Q1.7
opus --bitrate 140

Re: Point of transparency of Opus 1.2

Reply #26
Could someone please point me to where I can download these 'killer' samples? I'd like to try some ABX myself.

Also, OgGy, what made these so easy to identify? Is it pre-echo, hf roll off, something else?



Re: Point of transparency of Opus 1.2

Reply #29
... Anyway, as from opus@112kbps it becomes more difficult to ABX the samples, please find the results attached.
Thank you for testing.
Intereting as you get at 7/8 even @160 kbps with the applaud sample. Would you call the issue negligible at this bitrate? (I'm on holidays ATM and can't try for myself).
lame3995o -Q1.7
opus --bitrate 140

Re: Point of transparency of Opus 1.2

Reply #30
Actually, I believe I said that already in an other post but Chinese car stereos, mostly those cheap ones on ebay have a tendency to support open source codecs. Even though mine didn't advertise that it did, it supports APE, FLAC, OGG and OPUS. If you happen to own one of those I would suggest you to do a test. While on the outside some of them may look identical the internals might differ and they may support more or less codecs than the ones that they advertise.

I have owned two Chinese headunits (Android 4 + 5), and both were fucking horrendous. Constant issues with both software and hardware. Neither unit was what I would consider cheap, being around the £250 mark. The sounds quality was some of the worst I've eve heard (no, I didn't ABX).

The problem with using a non branded unit as suggested is that you get hardware which (in my opinion) has very little testing, and low test standards. The software is always junk. The reason good manufactures are limited to a small amount of formats is two reasons:

1) They are limited by available chips sets which are automotive grade. The Chinese ones tend just to use phone / tablet innards.
2) They need to limit the amount of support cost for the unit. I'd guess more formats means more customer support calls.

I've now moved to a Sony Apple Car Play unit now, which is of course, super limited in what it supports. But what it does, it does well.

Attached is a picture of the first Chinese unit I had. Looked ok, worked horribly.


These weren't the ones I was referring to. Anything Chinese Android based is terrible. What I was referring was basic 1DIN car stereos that go as much as 20 bucks on Ebay. I got one that actually plays all those formats I mentioned OPUS included, but an identical looking one that a friend of mine got didn't.

Re: Point of transparency of Opus 1.2

Reply #31
... Anyway, as from opus@112kbps it becomes more difficult to ABX the samples, please find the results attached.
Thank you for testing.
Intereting as you get at 7/8 even @160 kbps with the applaud sample. Would you call the issue negligible at this bitrate? (I'm on holidays ATM and can't try for myself).


Well @160kbps it is almost negligible but it suprises me how difficult it is to encode.  If I'm not mistaking the Opus Encoder uses only short blocks so that should not be the culprit ?

Re: Point of transparency of Opus 1.2

Reply #32
The reason good manufactures are limited to a small amount of formats is two reasons:

1) They are limited by available chips sets which are automotive grade. The Chinese ones tend just to use phone / tablet innards.
2) They need to limit the amount of support cost for the unit. I'd guess more formats means more customer support calls.
Boy! I'd love to know why chip sets manufactures insist on supporting almost-defunct (and, at least over here, unpopular) WMA and not AAC or Vorbis instead.
Listen to the music, not the media.

Re: Point of transparency of Opus 1.2

Reply #33
The reason good manufactures are limited to a small amount of formats is two reasons:

1) They are limited by available chips sets which are automotive grade. The Chinese ones tend just to use phone / tablet innards.
2) They need to limit the amount of support cost for the unit. I'd guess more formats means more customer support calls.
Boy! I'd love to know why chip sets manufactures insist on supporting almost-defunct (and, at least over here, unpopular) WMA and not AAC or Vorbis instead.

Because these were likely the prominent formats when the chipset was validated. Besides, no one in the real world knows what Vorbis is. These people are trying to sell mass market products, not appeal out out lying audio nerds like us.

Re: Point of transparency of Opus 1.2

Reply #34
Boy! I'd love to know why chip sets manufactures insist on supporting almost-defunct (and, at least over here, unpopular) WMA and not AAC or Vorbis instead.

Because these were likely the prominent formats when the chipset was validated. Besides, no one in the real world knows what Vorbis is. These people are trying to sell mass market products, not appeal out out lying audio nerds like us.
I guess it's something along those lines, and yes, you were right in pointing out Vorbis lack of consumer outreach.

But let us not forget that, outside Windows Media Player, WMA is not that popular either. So I wonder if there's also Microsoft's own doing in keeping such a supersed format alive for so long.
Listen to the music, not the media.

Re: Point of transparency of Opus 1.2

Reply #35
How does transparency of opus at 96 kbps compare against vorbis at 112 kbps (nominal bitrate in both cases)? I know this varies from person to person, but I would like to know forum members' opinions on this.

Re: Point of transparency of Opus 1.2

Reply #36
How does transparency of opus at 96 kbps compare against vorbis at 112 kbps (nominal bitrate in both cases)? I know this varies from person to person, but I would like to know forum members' opinions on this.
You'll learn with time (the sooner the better, so, in case you haven't yet, you should read this community's TOS ASAP) that, the very scientific empirical method which HA abides by (unlike the average "feel the force, Luke" audiophile website) will show you that, asking about whether a listening test comparing this or that format has ever been carried out (which, in your case, a simple search will tell you in a jif) - or even better: conducting yourself an ABX listening test - are totally valid under said guidelines - more specifically TOS #8.

Other than that, and hopefully, you'll grow accustomed to the fact that, over here, opinions regarding anyone's perception of quality are utterly worthless (because, let's face it, they're just that), unless properly corroborated by the afore-mentioned tests' results. 

So much so that any answer to that, without said results, would mostly be in direct conflict with TOS 8 - not to mention a contracdition per se, since, as you mentioned yourself: it "varies from person to person".
Listen to the music, not the media.

Re: Point of transparency of Opus 1.2

Reply #37
How does transparency of opus at 96 kbps compare against vorbis at 112 kbps (nominal bitrate in both cases)? I know this varies from person to person, but I would like to know forum members' opinions on this.
You'll learn with time (the sooner the better, so, in case you haven't yet, you should read this community's TOS ASAP) that, the very scientific empirical method which HA abides by (unlike the average "feel the force, Luke" audiophile website) will show you that, asking about whether a listening test comparing this or that format has ever been carried out (which, in your case, a simple search will tell you in a jif) - or even better: conducting yourself an ABX listening test - are totally valid under said guidelines - more specifically TOS #8.

Other than that, and hopefully, you'll grow accustomed to the fact that, over here, opinions regarding anyone's perception of quality are utterly worthless (because, let's face it, they're just that), unless properly corroborated by the afore-mentioned tests' results.

So much so that any answer to that, without said results, would mostly be in direct conflict with TOS 8 - not to mention a contracdition per se, since, as you mentioned yourself: it "varies from person to person".

Hmm. Maybe I asked the wrong question.

What I should have said: "I know this varies from person to person, but I would like to know the results of forum members' personal listening tests."

FYI I checked to see if relevant public listening tests had been carried out and they haven't. This is hardly surprising considering I am asking about a specific pair of codecs at non-identical bit rates.

I could carry out ABX tests of my own and maybe I will. However, I would also be interested to see some kind of a sample of results across different people.

Re: Point of transparency of Opus 1.2

Reply #38
I guess you are asking if the point of transparency of Vorbis is 112k for peope who consider Opus transparent at 96 kbit.
I can tell you for me, I'm 42 yrs old, and last time I've tested other codecs (mp3, aac, voris) the point of transparency was at 128k. That was few years ago, and I haven't tested them since, I am happily using them at slightly bigger bitrate (usually VBR which ranges from 100 to 150 k). Two months ago I've tested Opus, and it was seemingly transparent even at 64 k, and as safety net I've been encoding it at 80 k. But I am using it only for recorded movies and tv shows, which have mixed speech and music. For that it's more than perfect... for me :)

Re: Point of transparency of Opus 1.2

Reply #39
Playing around with some 'QUICK ABX testing' on my PC, which has Klipsch Pro-Media speakers(which are better than average PC speakers for sure(i have had them since the early 2000's)), i started off at 32kbps and then went to 48kbps and then stopped at the 64kbps setting in that, without actually finishing a ABX test, i simply did a QUICK test without spending too much time and it seems once i hit 64kbps i lose confidence in being able to more easily notice the FLAC file vs the Opus 64kbps file by simply clicking back and fourth between Sample A and Sample B to where i can tell it's noticeably more difficult once i hit that point to where i lose confidence in claiming i can quickly spot the FLAC and Opus file without actually completing a ABX test.

so in other words... once i hit the 64kbps setting it's not easy for me to detect artifacts anymore, especially when spending little time without focusing TOO much on things. because as others have mentioned once you start to strain on finding artifacts that's probably a good general guideline of a minimum bit rate you would consider using for general listening to the music straight up to enjoy it. because it appears some people around here can go beyond 128kbps Opus occasionally but i figure at that point you got to be more in that hardcore nitpicking level to where it's almost a non-issue when just straight up enjoying your music if by some chance some minor artifact turns up very briefly on a random song you got as to me it's not worth loading up on excessive bit rate just to 'maybe' clean up that semi-rare artifact that turns up if say the vast majority of music is either transparent or close to transparent to most people at say 96-128kbps range.

so given that info... i suspect ill be very similar to those who mentioned the 80kbps being hard to spot artifacts crowd of people that IgorC mentioned in here. who knows if there would be much of a difference for me if i tested with headphones. even if there is, i can't see myself going all that much higher with the bit rates in Opus especially assuming what was mentioned in this topic that Opus @ 96kbps is 'approaching transparency' is a good ball park figure.

p.s. for whatever it's worth ill be 38 years old later this month.
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).

Re: Point of transparency of Opus 1.2

Reply #40
hi
may i ask you about your settings?
do you use vbr or cbr
thanks


 

Re: Point of transparency of Opus 1.2

Reply #41
Nowdays there is no reason to go with CBR or ABR (unless for very particular reason like radio streaming with limited network speeds)

VBR is highly preferred for last 10+ years
VBR is both, more bitrate efficient and higher quality (true for any good lossy codec)

 
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